3:3 Li; :7 t * g 1,.“ '1 $51,»! : . [I EVE RUB: v,_: r ”i w .7 Umfivcsz“? [3 W OVERDUE FINES: \ 25‘ 9" do Der item RETURNING L18 my MATERIALs; W return to remov charge from circulation recor- METHODS OF NET ENERGY ANALYSIS AND ITS APPLICATION TO ENERGY PRODUCING SYSTEMS FOR COMPARISON OF ALTERNATIVE ENERGY RESOURCES BY Richard Neal Chapman A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Chemical Engineering 1981 ABSTRACT METHODS OF NET ENERGY ANALYSIS AND ITS APPLICATION TO ENERGY PRODUCING SYSTEMS FOR COMPARISON OF ALTERNATIVE ENERGY RESOURCES BY Richard Neal Chapman A methodology for the energy analysis of energy supply systems based on a combination of process and input-output analysis was developed and applied to a coal gasification complex, central receiver power stations, solar derived pro- cess heat, crOp production and the production of alcohol from corn. Acceptable analyses of fossil fuel based energy supply systems, conventional nuclear power stations, etc., were found in the literature. Results of the analyses of implementable alternatives and conventional systems are tabulated below: Smmary of Analyses Results Overall Maximum Process Resource Expansion Efficiencya Utilizgtion Rate System ( % ) Factor (%/year) gasoline from crude oil1 82.6 1.11 6311:; gasoline from coal1 61.0 1.49 60b gasoline from oil shale1 57.8 1.58 60 alcohol from corn2 110.0 0.00 40b electricity fran crude oil1 27.9 3.48 63b electricity frcm coal1 28.8 C 3.37 C 63 nuclear pacer stationa 34.1(790.0) 2.74(0.00) 84 central receiver power station“ 220.0 0.00 8b natural gasl 82.9 1.21 67b pimline gas from coal! 60.0 1.63 67 solar derived process heats 310.0 0.00 18 a .. E subsidy Overall Process Efficiency = EO/(BR+ES) resalroe E output . . . = ER m 0 Resource Utilization Factor ER/EO b - based on 0.05 capital requirement factor, 30 year system lifetime c - assures the energy ccntent of uranium to be freely available Richard Neal Chapman The energy flows into an energy supply system are mea- sured in units of primary energy (i.e., units of fossil fuel equivalents). The overall process efficiency is a measure of the total primary energy embodied in the energy produced and the resource utilization factor is a measure of the quantity of resource (that is converted into a useful energy product) utilized per unit energy produced over the lifetime of an en- ergy supply system. The total energy subsidy required by an «energy supply system is comprised of an initial capital energy investment followed by a continuous operational energy input (aver the lifetime of the system. The expansion of an energy smlpply system (i.e., the increase in the energy production by a: specific technology) requires a re-investment of the energy pnnoduced as the capital investment for the construction of nmxre facilities. Assuming a total re-investment of the annual enuergy produced, the maximum expansion rate measures the max- inunn annual increase in energy production a specific technol- oggr.is capable of achieving. In a growth oriented industrial socixaty, alternative technologies producing high quality ener- gyr Li.e., electricity and fuels) must have expansion capabil- ities; similar to their fossil fuel based counterparts if they are t1) operate as independent energy supply systems. jLiquefaction technologies utilizing coal and oil shale require: 34 and 42 per cent greater resource depletion respec- tively compared to crude oil for the production of the same quantity of gasoline due to less efficient conversions of Richard Neal Chapman resources to products. Alcohol from corn does not require the utilization of a non-renewable resource, but production is realistically limited to the annual domestic corn surplus which amounts to about 2 per cent of the annual gasoline con- sumption by surface vehicles in the United States? The lack of attractive alternatives for the production of liquid fuels suggests consideration of an electric mass-transit system. For example, an electric mass-transit system subsidized by conventional nuclear power plants could conserve 94 per cent of the crude oil resources or 96 per cent of the coal re- sources required for the provision of the same transportation service (assuming conversion efficiencies of 0.5 and 0.9 for the conversion of liquid fuels and electricity respectively to transportation work) The obvious alternative for the production of electricity from crude oil and natural gas is the increased production of electrcity from coal. Increased production of electricity from conventional nuclear power plants is limited by natural 0235 resources. It is estimated that the domestic U235 re- sources will be depleted in 40 years at the present rate of Utilization for fabrication of light water nuclear fuel rods. Central receiver power stations could conserve 87 per cent of the crude oil resource required for the production of the Same quantity of electricity, but are severely expansion rate limited compared to fossil fueled power plants (i.e., a Ciifference of an order of magnitude in the respective . u.“ .- I ..Q.ol . . ..¢a.1 ...-~ p Iov~~ v..., — .I‘v "o. -~. .. '....- u. 5“.» 'Ov - ‘ D On... IQ.. ll. III " o- u 9v 4:: I Richard Neal Chapman maximum expansion rates). Therefore, central receiver power stations are unacceptable as independent energy supply sy- stems in the context of a growth oriented industrial society. This suggests the use of the central receiver concept in the repowering of existing fossil fueled power plants in which a portion of the heat load of the turbogenerator is solar de- rived. Unfortunately, the central receiver concept is re- stricted to the southwest and western portions of the United States. In 1979, 56 per cent and 20 per cent of the energy con- sumed by the industrial and residential/commercial/non—energy sectors respectively of the United States was natural gas comsumed primarily in the production of process or domestic heat. The energy supply system which produces the process heat consumed in the manufacture of investment products such as concrete and steel (as opposed to end-use products) must have an acceptable expansion capability in order to allow the growth of the industrial sector. However, the expansion ca- pabilities of systems producing low grade process or domestic heat are not important characteristics. In such applications, solar derived process heat can conserve 73 per cent of the natural gas resource required to produce the same quantity of heat. However, solar derived process heat applications are location limited. Pipeline gas can be synthesized from coal, laut an increase of 35 per cent in the resource utilization cnompared to natural gas for the production of the same .‘po - c an... - us- 0.. ~‘ n... al- 2:- Richard Neal Chapman quantity of gas is required. It is clear that the total replacement of the domestic crude oil and natural gas utilization can be accomplished only through the extensive utilization of coal resources. However, the replacement of domestic crude oil and natural gas utilization by the year 2010 with coal derived products could deplete domestic coal reserves by about 2030. It is also clear that fossil fuel resources can be conserved through the implementation of solar derived liquid fuels, electricity and process heat and nuclear derived electricity. The trans- ition of energy supply from a fossil fuel based network of energy supply systems to a network of long-term technologies capable of replacing the utilization of fossil fuels will re- quire the availability of sufficient quantities of the energy products necessary to construct the long-term network of energy supply systems. The coal reserves are the only dom- estic energy resources capable of supplying such quantities of energy products. The extensive utilization of domestic coal reserves to replace the domestic utilization of crude oil and natural gas will not allow sufficient time to develop, construct and implement the technologies capable of replacing fossil fuels. Conservation of fossil fuel resources must be maximized to provide the greatest possible amount of time for the development, construction and implementation of fos- sil fuel replacement technologies. It is recommended that the consequences of proposed energy policies be quantitatively cal- - Richard Neal Chapman assessed through the dynamic energy supply modeling of the transition era in order to select the policy which maximizes the conservation of fossil fuels. 1Chapman, R.N., "Methods of Net Energy Analysis and Its Application to Energy Producing Systems for Comparison of Alternative Energy Resources," M.S. Thesis, Department of Chemical Engineering, Michigan State University, East Lansing, MI, Feb. 1981, p. 174. 2Ibid., p. 110, 500 mile coal delivery, 500 mile alcohol delivery. 3Ibid., p. 129, Rotty, system 2. I'Ibid., p. 96, design report 1, 500 mile prototype component delivery, 30 year system lifetime. 5Ibid., p. 100, system II, 5 per cent utility requirement. 6Chambers, R.S., Herendeen, R.A., Joyce, J.J. and iPenner, P.S., "Gasohol: Does It or Doesn't It Produce 2Positive Net Energy," Science, Vol. 206, Nov. 1979, pp. 789-795. To Barb and Bryan. ii ACKNOWLEDGMENTS I wish to express my deepest appreciation and gratitude to Dr. Martin Hawley and Dr. Herman Koenig for their support and guidance, to David Reister and the staff at the Institute for Energy Analysis, Oak Ridge Associated Universities, for their co-operation and assistance, and to Barbara Joan Chapman, whose invaluable time and effort made this Thesis a reality. iii TABLE OF CONTENTS LIST OF TABLES Xi LIST OF FIGURES xxiii CHAPTER 1. CONCEPTS, DEFINITIONS AND USES OF ENERGY ANALYSIS AND THE OBJECTIVE OF STUDY Introduction 1 Energy Analysis and the Energy Crisis 2 Objective of Study 5 Definitions and the Basis of Energy Analysis 7 Summary 12 CHAPTER 2. DEVELOPMENT OF METHODOLOGIES Introduction 14 Process Analysis 15 Input-Output Analysis 20 CHAPTER 3. APPLICATION Energy Analysis Applied to Industrial Processes 34 Data required 34 Definition of nameplate processing system 37 Determination of the energy inputs and outputs of the system 38 Energy analysis results 59 Example of Energy Analysis Application: Energy Analysis of a Coal Gasification Complex 68 Comments 68 Summary of energy analysis 69 Basis of analysis 72 iv M‘s-n- - .- v... o.- . pov- .h- 5. fl) ru '1 (I! (I) Determination of energy inputs of the system 78 Determination of energy outputs of the system 89 CHAPTER 4. SUMMARY OF ENERGY ANALYSES Introduction 91 Summary of Energy Analysis of Central Receiver Power Stations . 91 Description of system 91 State of system outputs 92 Energy inputs and outputs of system 93 Energy parameters of system 95 Summary of Energy Analysis of Systems Supplying Industrial Process Heat from Solar Radiation 95 Description of system 95 State of system outputs 98 Energy inputs and outputs of system 98 Energy parameters of system 98 Summary of Energy Analysis of Crop Producing Systems 101 Description of system 101 State of system outputs 101 Energy inputs and outputs of system 102 Energy parameters of system 102 Summary of Energy Analysis of the Production of Alcohol from Corn 102 Description of system 102 State of system outputs 107 Energy inputs and outputs of system 107 Energy parameters of system 107 v gu‘ n-c - . a '01 .ll-‘ a ‘ -1 a... ‘v A‘- a ‘. U h ‘ ~~c 5‘ _ a \I v a .1 n " ‘: J. ‘~. .‘c._ . .7 , ‘h u o.‘ o.‘ ‘o ‘ 0"- : n o“ 1. ~- ~. ‘0 .I n ‘ .1 “ A \‘~ U. I c v A I v a *. R .1 ‘V 0 ‘§ '» b. o.‘ u CHAPTER 5. BACKGROUND AND HISTORY OF ENERGY ANALYSIS APPLICATIONS Introduction Summaries of Individual Analyses Nuclear fuels Solar energy Summaries of Comprehensive Energy Analysis Studies Energy supply systems based on fossil fuels Ocean Thermal Energy Conversion (OTEC), in-situ oil shale processing, fluidized bed coal combustion versus conventional coal combustion and municipal waste disposal Nine electricity generating systems CHAPTER 6. CONCLUSIONS, IMPLICATIONS AND RECOMMENDATIONS Introduction First Level of Energy Analysis Implications Solar Energy Nuclear energy Fossil fuels Second Level of Energy Analysis Implications Comments Comparison of alternative and conventional energy supply systems for the supply of specific end-use products Discussion of the provision of transportation services Electricity He at vi 111 114 114 128 168 168 175 181 187 189 189 206 208 210 210 213 213 221 224 v . Third Level of Energy Analysis Implications General characteristics of a future energy supply scenario: transition into a new era Dynamic energy analysis Recommendations for Future Efforts in Energy Analysis Comments Development Application Interpretation APPENDIX A. ENERGY ANALYSIS OF CENTRAL RECEIVER SOLAR THERMAL POWER STATIONS General Approach Description of Data Comments High efficiency collector system Lower efficiency collector system Determination of Energy Embodied in Prototype Components General approach for extension of process analysis to prototype component manufacturing systems Definition of nameplate processing systems responsible for the manufacture of prototype components Application of process analysis to the prototype component manufacturing systems Application of input-output analysis to prototype component manufacturing systems Application of the disaggregation of the energy intensity coefficients to prototype component manufacturing systems vii 229 229 233 242 242 243 243 244 245 249 249 249 251 251 251 253 254 261 274 Definition of the Nameplate Processing System Application of Process Analysis Comments Inputs Outputs Application of Input-Output Analysis Application of the Disaggregation of Energy Intensity Coefficients APPENDIX B. ENERGY ANALYSIS OF THE PRODUCTION OF INDUSTRIAL PROCESS HEAT FROM SOLAR RADIATION General Approach Description of Data Estimation of Energy Embodied in Collectors General approach to the estimation of the energy embodied in solar collectors Application of process analysis to solar collectors Application of input-output analysis to solar collectors Summary of the results of the application of input-output analysis to solar collectors Application of the disaggregation of energy intensity coefficients to solar collectors Definition of Nameplate Processing System Application of Process Analysis Inputs Outputs Application of Input-Output Analysis Summary of the Results of Input-Output Analysis Application of the Disaggregation of Energy Intensity Coefficients viii 277 277 277 277 283 284 291 292 295 295 295 297 302 302 302 310 311 311 314 315 319 320 to. APPENDIX C. ENERGY ANALYSIS OF CROP PRODUCING SYSTEMS General Approach 321 Description of Data 325 Definition of Nameplate Processing System 326 Application of Process Analysis 328 Nameplate processing system 328 Extension of process analysis 334 Application of Input—Output Analysis 339 APPENDIX D. ENERGY ANALYSIS OF ALCOHOL PRODUCTION FROM CORN General Approach 344 Definition of Nameplate Processing System 345 Application of Process Analysis 346 Inputs 346 Outputs 350 Extension of Process Analysis 351 Energy subsidy and content of delivered corn 351 Energy required for delivery of coal and products of system 352 Application of Input-Output Analysis 353 Application of the Disaggregation of Energy Intensity Coefficients 358 LIST OF REFERENCES Chapter 1 359 Chapter 2 360 Chapter 3 361 Chapter 4 362 Chapter 5 364 Chapter 6 367 ix Appendix Appendix Appendix Appendix 370 371 373 374 on. u 3.11. LIST OF TABLES Total primary energy consumed per dollar spent for 1960-1978 List of energy inputs to the first level of energy analysis of a generalized industrial process List of industrial sectors responsible for production of common industrial equipment (2) Trade and transportation margins for sales to final demand of the coal producing sector (2) List of trade and transportation sectors (2) Total requirement for delivery of coal input Trade and transportation margins for sales to final demand for sector 4006 (2) Trade and transportation cost for a non- energy product input from sector 4006 of 1,000,000 $1967 producer's cost and 1,063,830 $1967 purchaser‘s cost Suggested format for reporting of energy analysis results Definitions of energy analysis parameters Comparison of energy parameters for systems with internal and external utilities supply Comparison of energy gain and total energy subsidy as a function of position in the trajectory 32 40 49 51 52 52 53 55 60 63 65 67 3.13. 3.14. 3.18. 3.27. Secondary products of coal gasification process Properties of Navajo coal (4) Properties of the synthetic pipeline gas (4) Energy inputs of the system Energy outputs of the system (4) Energy parameters of coal gasification complex List of nameplate processing units (4) Quantities of energy inputs 1 and 2 (4) Energy inputs 4 and 5 (4) Energy inputs 6, 7, 8 and 9 (4) Energy requirements for the transportation of coal Deflation of cost data (lifetime investments) Deflation of cost data (annual investments) Trade and transportation margins Modification of purchaser's prices into producer's prices, and the conversion of the producer's prices into primary energy (lifetime energy investments) Modification of purchaser's prices into producer's prices, and the conversion of producer's prices into primary energy (annual energy investments) Trade and transportation margins (2) Conversion of energy flows into primary energy (annual energy investments) xii 70 70 71 73 74 75 77 79 80 81 82 83 83 84 85 86 86 87 .0- cl.- 0'.- ‘1 ‘.. Disaggregation of the energy intensity coefficients for sector 1100 (3) Energy inputs 3 and 10 Energy input 11 Energy outputs of the system Annual energy inputs required by system 1 (3) Annual energy input required by system 2 (3) Energy parameters of systems analyzed (3) Annual energy inputs of solar industrial process heat systems (5) Annual energy outputs of solar industrial process heat systems (5) Energy parameters of solar industrial process heat systems assuming a 100 mile transportation distance for collector delivery (5) Energy inputs of crop producing systems (7) Energy outputs of crop producing systems (7) Energy parameters of crop producing systems (7) Secondary products of the alcohol plant Energy inputs of the alcohol plant (9) Energy outputs of the alcohol plant (9) Energy parameters of alcohol production based on an energy resource of solar radiation (9) Fuel cycle parameters of nuclear power plant designs analyzed by P. F. Chapman (5) Jdii 88 88 89 90 93 94 96 99 99 100 103 104 105 106 108 108 110 115 5.16. 5.17. Enrichment energy requirements reported by the various authors Lifetime energy inputs to systems analyzed by P. F. Chapman (5) Lifetime energy inputs to systems analyzed by Rombough (8) Lifetime energy inputs to 1000 MW(e) nuclear power plants analyzed by Rotty, et a1. (7) Parameters of nuclear power plant systems analyzed by Rotty, et a1. (7) Lifetime quantity and energy content of natural uranium required by the systems analyzed by Rotty (7) Lifetime energy outputs of nuclear power plant analyzed Energy parameters of nuclear power plant systems analyzed Lifetime energy inputs of solar thermal electric systems Lifetime energy outputs of solar thermal electric systems Energy parameters of solar thermal electric systems Characteristics of solar energy supply systems analyzed by Wagner (26) Lifetime energy inputs to the systems analyzed by Baron (2) Lifetime energy outputs of systems analyzed by Baron (2) Annual energy inputs to systems analyzed by Wagner (26) Annual energy outputs and energy savings of systems analyzed by Wagner (26) 120 122 123 124 125 126 127 129 134 134 136 137 139 140 140 141 5.32. Energy parameters of solar domestic energy supply systems Transportation distances for delivery of biomass to processing site (22) Energy inputs required for corn production reported by Pimentel (20) Energy outputs of corn production reported by Pimentel (20) Energy requirement for production of forest biomass reported by Blankenhorn (22) Energy parameters of corn production system analyzed by Pimentel (20) Energy parameters of forest biomass production systems analyzed by Blankenhorn (22) Description of systems analyzed Energy inputs and outputs of alcohol producing systems Energy parameters of alcohol producing systems Energy requirements and potential energy outputs of photovoltaic cells manufactured during a one-year period Energy parameters of the production of photovoltaic cellsa Description of fossil fuel trajectories analyzed by Mechler (28) Energy parameters of fossil fuel resources in terms of various end used (all trajectories are based on 1 x 109 Btu/yr resource requirement) (28) Energy parameters and outputs of systems analyzed by Perry (29) 142 145 148 148 149 150 151 158 161 163 166 167 170 174 180 Description of systems analyzed by Pilati (30) Lifetime energy requirements per Btu lifetime energy output of systems analyzed by Pilati and Richards (30) Energy parameters of systems analyzed by Pilati and Richards (30) Breakdown of the capital energy subsidy of central receiver power stations (9) Energy gains and the breakdown of the total energy subsidies of the production of corn and slash pine (15) Breakdown of the energy subsidy required for the production of alcohol from corn (16) Breakdown of the energy subsidies of a 1000 MW(e) BWR (0.3 tails assays with and without fuel recycle) and a coal fired power plant and the energy gains of each system Comparison of liquid fuel supply systems Comparison of electricity producing systems Comparison of process and space heating, and domestic hot water supply Comparison of the relative primary energy consumed per unit of transportation work provided by various energy supply systems Embodied energies and end-uses of electricity produced by various systems Primary energy embodied in the heat products of various supply systems Definition of energy supply model parameters 182 185 186 194 201 204 206 214 215 217 220 223 226 235 Constitutive relationships for dynamic energy supply model Energy balances for dynamic energy supply model Analogies between manufacture of prototype components and established industries Raw materials required for fabrication of the 23,310 heliostats described in design report 1 (1) Raw materials required for fabrication of one heliostat described in design report 2 (2) Energy required for heliostat delivery Raw materials required for fabrication of the 15 receivers described in design report 1 (1) Raw materials required for fabrication of the 3 receivers described in design report 2 (2) Energy required for delivery of receivers described in design report 2 Raw materials required for fabrication of the 15 towers described in design report 1 (1) Raw material requirements for fabrication of the 3 towers described in design report 2 (2) Deflation of heliostat cost data reported in design report 1 Deflation of heliostat cost data reported in design report 2 Trade and transportation margins Jodi 238 239 252 255 256 256 258 259 259 260 260 262 262 263 1;.j13. Producer's prices and embodied energies of raw materials required for fabrication of the 23,310 heliostats described in design report 1 Producer's prices and embodied energies of raw materials required for fabrication of one heliostat described in design report 2 Deflation of receiver cost data reported in design report 1 Deflation of receiver cost data described in design report 2 Trade and transportation margins Producer's prices and embodied energies of raw materials required for fabrication of the 15 receivers described in design report 1 Producer's prices and embodied energies of raw materials required for fabrication of the three receivers described in design report 2 Deflation of tower cost data reported in design report 1 Deflation of tower cost data reported in design report 2 Trade and transportation margins Producer's prices and embodied energies of raw materials required for fabrication of the 15 towers described in design report 1 Producer's prices and embodied energies of raw materials required for fabrication of the three towers described in design report 2 Summary of results of input-output analysis applied to prototype components xwiii 264 265 266 267 267 268 269 270 270 271 271 272 273 A,.2223 . A.2259 - A-33 A-34 A-35 Disaggregation of the auto-industry's energy intensity coefficient (sector 5903) (3) Disaggregation of the boiler shOp industry's energy intensity coefficient (sector 4006) (3) Disaggregation of the new construction industry's energy intensity coefficient (sector 1103) (3) Energy embodied in non-delivered prototype components fabricated at the manufacturing site Remaining components and general facilities required by the system described in design report 1 (1) Remaining components and general facilities required by the system described in design report 2 (2) Raw materials required by the system described in design report 1 (1) Maintenance requirements Energy outputs of systems Deflation of cost data reported in design report 1 Deflation of cost data reported in design report 2 Trade and transportation margins (sales to final demand) (5) Producer's prices and embodied energies of remaining components, general facilities and maintenance services required by the system described in design report 1 Producer's prices and embodied energies of remaining components, general facilities and maintenance services required by the system described in design report 2 274 275 275 276 279 281 282 283 283 285 286 287 288 289 Summary of the application of input- output analysis Energy required for the installation of components at the system site Description of solar collectors analyzed (6) Description of system analyzed (2) Raw materials required for fabrication of the collectors analyzed Energy required to deliver collectors Deflation of collector cost data Trade and transportation margins Producer's prices and embodied energies of raw materials required for collector fabrication Summary of results of the application of input-output analysis to the solar collectors Energy embodied in the non—delivered collectors fabricated at the manufacturing site Collectors required by the systems analyzed Remaining components required by the systems analyzed (2) Annual maintenance requirements (2) Annual energy outputs of systems analyzed (2) Deflation of remaining component and maintenance cost data Trade and transportation margins (7) (sales to final demand) 290 291 294 296 298 301 303 305 306 308 309 312 313 314 314 315 316 Producer's prices and embodied energies of remaining components and maintenance requirements Annual energy embodied in delivered utility requirements Summary of the results of input- output analysis Energy embodied in the installed, non- delivered components of the systems analyzed Energy embodied in various fertilizers, agricultural chemicals and seeds reported by Roller and Keener (2) Expected yields, location of production, energy contents, growth cycles and moisture contents of the crOps analyzed Weights of specific farm equipment and the quantities (i.e., number of units) of each unit required for production of the crops analyzed (2) Total weight and the purchaser's price of equipment required for production of the crOps analyzed from 162 hm2 per growth cycle (2) Quantities of seed, fertilizer, and chemicals required for production of crops analyzed (2) Quantities and energy contents of utilities required for production of crops analyzed (2) Energy outputs of crop producing systems Energy embodied in the non-delivered raw materials required for crOp production Weights of capital, raw material and utility inputs for crop production and the energy required for delivery of the inputs 317 318 319 320 323 327 329 330 331 332 333 334 336 D.10. Weight to be transported and the energy required for transportation of the crOps analyzed Utility requirements for drying and chipping of crOps analyzed Deflation of equipment cost data Producer's prices and embodied energies of non-delivered equipment required for crop production Energy contents and embodied energies of the non-delivered utilities required by the nameplate processing system for crOp production Energy contents and embodied energies of the delivered utilities required for crop processing (i.e., drying and chipping operations) Definition of operations required for production of alcohol from corn (1) Purchaser's prices of required components and field materials (1) Raw material requirements (1) Utility requirements Energy outputs of alcohol plant Energy content and subsidy of delivered corn (15 per cent moisture content) (7) Energies required for delivery of coal and the system's products Deflation of cost data Trade and transportation margins Producer's prices and embodied energies of required capital and raw materials 337 338 340 341 342 343 347 348 349 350 351 351 352 353 354 356 1).;Ll. .D..112. Energy embodied in utilities Energy required for delivery of utilities (excluding coal) LIST OF FIGURES First and second levels of energy analysis (- - - first level, second level) Trajectory of electricity produced from coal Definition of the energy balance used in input-output analysis Generalized material and energy flows of an industrial process Coal gasification trajectory Energy flows of an energy supply system System with external supply of utilities System with internal generation of utilities Trajectory I Trajectory II Energy supply model Definition of nameplate processing system for manufacture of prototype component xxiii 357 357 10 17 22 39 44 62 64 65 66 66 241 253 CHAPTER 1 CONCEPTS, DEFINITIONS AND USES OF ENERGY ANALYSIS AND THE OBJECTIVE OF STUDY Introduction Industrial Revolution - the change in social and ec2c>11<3mic organization resulting from the replacement of hiar1Ci tools by power tools and machines and the development Of large scale industrial production (Webster). The energy crisis now facing the United States, alléi ‘the western industrialized world, exists because of the t1Z‘Eil”lsition from a society dependent upon human and animal e1"lelli‘gy to a society dependent upon thermal and electrical e‘16-3—‘1t‘gy currently produced primarily from fossil fuels. In reality, society has changed from a self-sufficient system (j-~€E.., society consumed only what it could produce) to a 1101'l‘s.elf-sufficient system. Initially, the fossil fuel resources seemed to be infinite. However, the energy supply was all too easily tapped and the industrial society grew as Quickly as man could extract the energy from the earth. AS the industrial society grew out of control, the eventual depletion of its fuel became evident as was foreseen in 1912 1Wthe Nobel prize-winning physicist Frederick Soddy (1). 1 Civilization as it is at present, even on the purely physical side, is not a continuous self- supporting movement. It becomes possible only after an age-long accumulation of energy, by the supplementing of income out of capital. Its appetite increases by what it feeds on. It reaps what it has not sown and exhausts, so far, without replenishing. Its raw material is energy and its product is knowledge. The only knowledge which will justify its existence and postpone the day of reckoning is the knowledge that will replenish rather than diminish its limited resources. Sixty-eight years later, society is beginning to realize the problem it faces. Society has grown into a giant energy sink, increasingly consuming energy at a rate of 3.5% per year (2) from a finite well of fossil fuels while producing no energy itself. This growth rate is further aggravated by the fact that each new Btu of energy extracted :Erom the earth requires the investment of more energy than tJie previous Btu (3) and that a Btu from coal, the energy resource which is supposed to replace petroleum resources 113 the short-term future, requires more energy to extract £31161 process than a Btu from petroleum to produce the liquid fuels that society is dependent upon (4) . Thus, the energy sulzplply projections are overestimated, possibly seriously overestimated. Energy Analysis and the Energy Crisis The "energy crisis" which now confronts the United States can be stated as follows: The exhaustion of fossil fuel based energy, which 13 Presently the backbone of society, grows near and a 9°11<=y for the implementation of alternative energy 3 technologies is yet to be developed. The remaining supply of fossil fuels must be used for the following purposes: 1. To develop and implement an alternative energy supply system to eventually replace fossil fuels. 2. To sustain society at an acceptable standard of living until the alternative energy supply systems can replace fossil fuel based energy. Currently, economic evaluations of alternative energy supply systems serve as the basis for energy policy formulation. Economics assumes the existence of an infinite dollar supply and, thus, an infinite energy supply. Traditional economics cannot deal with the depletion of investment rwasources. Furthermore, an economic analysis is not a pnxrely physical evaluation due to the distortion of the VEiJJJe allotted to products based on human values, govern- nnerrtal price regulation and tax incentives, etc. Thus, economics cannot be relied upon as the basis for an energy policy that will allow the transition of society from fossil fuel dependence to a renewable energy resource wistlucyut destroying the industrial nature and the high standard of living of the present society. Energy analysis 3311 éijxi in the developing of a competent energy policy. The fOllowing paragraphs discuss the uses of energy analysis in 'tllEB context of the energy crisis facing the United States. The immediate energy supply crisis is the depletion 0f Crude oil resources. It is not clear that this country 4 can implement a policy to enable an orderly transition from a liquid fuel dependence to an alternative energy supply system without a significant decrease in the standard of living. The probability that an orderly and comfortable transition from liquid fuels is unlikely rests with the lack of a viable alternative energy resource for the production of liquid fuels. This statement is based on energy parameters, which result from energy analyses, of alternative energy systems that produce liquid fuels. The energy parameters allow a comprehensive comparison of energy supply systems that are being con- sidered for a specific end use, which is one of the tools :necessary for policy decision that energy analysis can provide. The depletion of petroleum is only the immediate ;pfluase of the overall energy crisis. Furthermore, evidence eeacists which suggests that this short-term crisis can only 1363 .resolved through the use of the United States' vast coal resources, the immediate implementation of light water nuclear power stations and solar energy when applicable. However, these energy supply systems are only interim SOlutions to the energy crisis. The long-term solution will necessarily be based on a renewable energy resource such as solar, or on resources which by definition may not be renew- au3163. but offer a supply of energy from an unlimited resource, Such as the nuclear breeder concept and fusion. The con'E'tlnlction and implementation of any energy supply system 5 capable of sustaining society requires an enormous invest- ment of energy. Thus, the transition to a renewable energy supply system places a tremendous load on the interim energy supply system. The development of a long-term energy transition policy must begin now to insure that sufficient energy is available to construct the long-term energy supply system. Energy analysis can be used to predict the feasibil- ity of a transition energy supply policy through a dynamic energy supply and demand model. Using the energy parameters obtained from energy analysis and a proposed energy supply scenario, the dynamic model will predict the energy available for consumption given an annual energy supply system growth rate, or, in the opposite sense, the model will predict the energy available for investment given an end-use consumption requirement. Both modes of operation of the dynamic supply and denand model predict the transition behavior of an interim energy supply system. Thus, the model will predict whether or not the interim energy supply system is capable of both SuStaining society and constructing the long-term energy SuPplysystem. Objective of Study The ultimate objective of this study is to provide information and insight essential to the develOpment of a competent present and future energy policy. These inputs to energy policy formulation are the interpretations and :hWRlications of the results of energy analyses applied to proposed alternative energy supply systems. The study is three-phased in nature. First, it is necessary to define a methodological approach for the energy analysis of produc- ing systems which can be applied consistently to all systems analyzed. Secondly, the methodology is to be applied to alternative energy supply systems, or to search out analyses already performed that are acceptable under the definition of the approach outlined. The energy supply systems that are believed to be possible candidates as energy alterna- tives are listed below: 1. Coal a. for the production of electricity b. gasified to produce high Btu pipeline gas c. liquefied to produce a synthetic crude oil 2. Solar a. collection of radiation as heat for either direct use or for the production of electricity b. conversion of radiation directly to electricity (photovoltaics) c. conversion of wind directly to electricity d. conversion of solar radiation to stored chemical energy as biomass via photo- synthesis and the subsequent harvesting, collection and processing of the biomass for the production of solid or liquid fuels e. conversion of ocean thermal energy directly into electricity 3. Nuclear a. breeder reactors b. fusion Several of these alternatives are not analyzed due to lack of data (i.e. , breeder and fusion). The methodology must also be applied to the present energy supply systems for comparison purposes. The present energy supply systems considered are listed below. 1. Petroleum a. production of liquid fuels b. production of electricity 2. Natural Gas a. high Btu pipeline gas b. production of electricity 3. Coal a. production of electricity 4. Nuclear a. light water reactors The third phase of the study is to understand the implications of the results of energy analysis and to use the results as the basis for energy policy recommendations. This final objective of the study implies the development Of a dynamic energy supply model which can predict the implications of proposed energy policies and the dynamic behavior of proposed energy supply scenarios. Definitions and Basis of Energy Analysis (4, 6, 7, 8, 9) Energy analysis is the quantitative assignment of an €31lergy equivalence to all actions (which would not have occurred if the system were not in existence), and materials required to construct, maintain and operate all processes wltl'lin the system, and to all products of the system, over the useful lifetime of the system. Immediately, three questions arise which ultimately serve as the basis for the analysis. The questions are: 1. How are the energy inputs and outputs of a process determined? 2. How is an energy equivalence assigned to an input or output of a process? 3. What is the unit energy of an energy equiva- lence? The definition of the unit energy establishes a hierarchy of the various energy forms by adopting a specific form and amount of energy as the unit equivalence and defin- ing the relationship of other energy forms to this unit equivalency. The establishment of the inputs and outputs of a Process is a matter of convention. The convention suggested is based on the concepts of trajectories and levels of energy analysis. An energy analysis is applicable to any SYStem which involves inputs and outputs of some form of energy, Inputs are usually in the form of energy embodied in materials and equipment, an indirect input of energy, or as a direct use of energy, such as heat or electricity. The Outputs can be in the form of embodied energy, direct energy or inthe form of energy conservation (the energy saved becomes the energy output). ‘Phe energy analysis of a system is in reality the energyr analysis of many systems whose outputs are combined a . . nd eventually result in the system which is under 9 consideration. This interaction of multiple systems defines the trajectories of a specific system. The boundaries of the entire system are set by the definition of energy analysis. However, the boundaries of the many subsystems comprising the entire system are arbitrary (i.e., processes may be combined or isolated resulting in different subsystems of the entire system). This concept is discussed further in the methodology and application chapters. The analysis is begun by establishing some initial boundaries of the system under consideration (usually con- cerning a specific operation such as conversion of processed and delivered coal into electricity). This boundary defines the first level of energy analysis illustrated by the dotted boundary in Figure 1.1. Next, the systems responsible for the manufacture and delivery of the inputs required by the sYstem under consideration must be identified and their boundaries specified, thus defining the inputs to those SYStems. This is the second level of analysis illustrated by the solid boundary in Figure 1.1. (Note: Often the sYStemand the delivery of the system's products are consid- ered as separate systems. However, the system producing the prodfiurt and the delivery of the product are included in a lev‘fil of energy analysis.) The expansion of this network of S'.'3?stems results in horizontal (following the feed path) and Vertical (following the paths of direct energy usage, raw'materials and capital of each system) trajectories that: trace the system under consideration back to inputs 10 Aam>ma pcoomm III.Ho>mH umufim I I Iv pooh mfioooem mfiwfifim mflmzamcm mmumcm mo mam>ma cocoon pom umnflm .H.H Gunmen m s e e s e m s .l l l .1 l l l P w P wt 1 P wt .1 P n csmmmemmmmcmmmmcmm a . I . e . . I 1 awesome 1 3808.82 38m 0 8830: A moaosoonm memummm mcfloscoum msmummm mcflQSposm mewumwm ._. , s, e m m e _ a mm m _ i . on man ll of raw materials and energy extracted from the earth, and human labor (a free energy resource). This approach to energy analysis is known as process analysis. However, the rigorous use of this analysis becomes extremely complicated immediately after the first level and impractical after the second level. The enormous task of developing the required tra- jectories to complete the analysis via the process analysis approach can be replaced by an economic correlation of the energy flows between sectors of the United States' economy and the energies embodied in the output of each sector. The method is referred to as input-output analysis and is based on the economic input-output structure of the United States. The economy is grouped into 357 producing sectors and the dollar transactions between sectors as well as each sector's output are calculated for a specific year based on data obtained from the national census (5). The economic structure is calculated at five-year intervals with the data for the year 1972 being the most recent published. Using ‘this data, energy intensity coefficients for each of the 357 producing sectors are calculated in the form of a unit (embodied energy per unit measure of product (see Chapter 2 :Eor description of the calculation). The most recent avail- iable set of energy intensity coefficients are based on the .input-output data for the year 1967. The coefficients for 'the year 1972 are presently being generated and are 12 anticipated to be available in the summer of 1980 (10). The use of these coefficients incorporates a certain level of uncertainty in the results of the analysis (discussed in Chapter 2) but allows the completion of an analysis not feasible with process analysis alone. The basic strategy for an energy analysis is out- lined as follows: 1. Determine the inputs and outputs of the system under consideration by the use of process analysis to define the first level of the energy analysis. 2. Assign energy equivalaxxs to the inputs of the system by the use of the energy intensity coefficients from input-output theory. The energy output of the system is the energy content of the system's products (discussed in Chapter 3). The unit energy of an energy equivalence is a matter of convention. However, the unit energy of an energy equiv- alence must be well defined and used consistently throughout the analysis. The definition of a unit of primary energy is adOpted for this work (defined in Chapter 2) in order to be consistent with and allow the use of data from other sources such as the United States Bureau of Mines. Summary The energy crisis facing the United States is two- Phased and must be solved in two steps as follows: 1. Transition from a petroleum dependence to a coal, nuclear (light water) and solar (where applicable) dependence. 13 2. Transition from an interim energy supply system to a long-term energy supply system. The first transition cannot occur without significant conservation and a decrease in the United States' standard of living. However, it is possible to implement an orderly and comfortable transition to the long-term energy supply system with the proper energy policy. Planning for the second transition must begin now. It is clear that economics alone cannot give the information necessary to develOp either the short-term or long-term energy policies. Energy analysis can aid in the development of an energy policy through end-use comparison and the prediction of dynamic behavior of alternative energy supply systems. Energy analysis is the quantitative assignment of an energy equivalence to the inputs and outputs of a system. The unit energy of an energy equivalence is defined to be a unit of primary energy. The identification of the inputs and outputs of a system is accomplished through the process analysis of the first level of energy analysis. The energy equivalence is assigned to the inputs of the system through input-output analysis and the energy output of the System is the energy content of the system's products. CHAPTER 2 DEVELOPMENT OF METHODOLOGIES Introduction The methods used to perform an energy analysis vary widely from author to author usually without just- ification or documentation of the method used. Thus, by choosing the methodology cleverly, the results of an analysis can be made to yield the conclusion desired by the author. This use of energy analysis denies credi- bility to the results or conclusions that may be reached. For this reason, the science by and large has not been considered seriously as a tool in energy policy develop- ment. By precisely defining the methodologies used and documenting the analyses performed, the results and conclusions of this study can provide valid information for policy development as well as providing an under- standing of the implications of specific energy policy Options. There presently exists two basic approaches to energy analysis that are generally considered viable and acceptable. These are process analysis, the preferred and most accurate method, and input-output analysis. An energy analysis usually incorporates both methodologies l4 15 depending upon the characteristics of the system, and the amount and type of data available. The characteristics of the system will determine the extent of process analysis required, while the available data determine the extent possible for the use of process analysis. An article by P. F. Chapman (1) offers an excellent introduction to energy analysis methods. Process Analysis Although this method of energy analysis appears frequently in the literature (1, 2, 3), it is not clear where the approach originated nor is it clear as to how the approach developed. An introductory description of process analysis is contained in the Energy Analysis Handbook by Bullard, Penner and Pilati (3). The name adOpted for this method of energy analysis is perhaps more appropriate than often realized. That is, the analysis yields results applicable to a specific pro- cess only and not to its products. At first, the point made may seem trivial. It is, however, a very important basis of this analysis which is realized when attempts are made to compare "energetics" of a product produced by Several different processes, or when attempts are made to determine the energy embodied in a product of a process haVingmany products (such as an oil refinery). Since Embcess analysis is totally dependent upon the details of the specific process, the analysis can only be as complete ‘0‘ “V Ill .- v. 16 as the process description itself. Thus, great care must be taken when selecting a process description for analysis. The first step in the analysis is the selection of an apprOpriate process description. Next, it is necessary to draw a boundary around the process to define the inputs and outputs of the system allowing the development of the trajectories of the system. Consider, for example, the produCtion of electricity from coal (see Figure 2.1). As shown in the trajectory drawn, the boundary is drawn such that the inputs are in-place coal, direct energy use, and energy embodied in materials and capital, and the output is distributed electricity. Notice, as shown by the dotted lines, that the boundary is arbitrary. The in-place coal input can be replaced by a delivered coal, processed coal or extracted coal input depending on whether the energy embodied in the different types of coal inputs are known. In other words, the boundary must be enlarged until the energies embodied in the inputs are known. Also, note that vertical as well as the horizontal trajectories may be necessary so that the energies embodied in the inputs are known. The smallest boundary of Figure 2.1 includes the Electric plant and the distribution of electricity and represents the first level of analysis. To develop the Second level of analysis, not only would it be necessary t0 include the two previous horizontal steps, transportation and processing, all applicable vertical steps would need to 17 Hmoo Eoum couscoum huflowuuowam mo muouommmue .H.N musmflh anntal materials mantel materials drnxx aflnxal mananals duxct cagfial manauals dnxnt anntal Habanals dumxt dhect e I wHfifiHRxfimmfic Benoflfimeo mQRfimQHRH fisoefloflm H Roofifimeo 003m 6 18 be included (i.e., the production and transportation of direct energy used, materials and capital for the electric plant and distribution of electricity systems). The complexity of extending process analysis to higher levels of energy analysis should now be apparent. Thus, as noted in Chapter 1, process analysis of the higher levels of energy analysis is usually approximated by the use of energy intensity coefficients from input-output theory. However, the energy intensity coefficients are often inadequate especially when dealing with inputs from new technologies (i.e., heliostats for electricity from solar thermal derived heat) which may not be included in one of the industrial sectors. Also, the input-output method gives average energy intensities representing all production processes of a product which may not be suitable in some instances. Thus, process analysis is extended to as many of the higher levels as permitted by available data. This usually results in an extension of process analysis along the horizontal trajectory. While the specific definition of the unit energy Of the energy equivalence does not directly influence the use of process analysis, it does establish the basis for energy accounting. The basis for energy accounting defines a hierarchy among various energy forms as well as which energy forms are considered as countable energy inputs. A unit energy of primary energy used by the Bureau of l9 Mines is chosen as the energy equivalence for this study and is defined as follows: E = E p coal + E + on . crude Eelectric Primary energy where E P Ecoal E Btu's of coal (based on the higher heating value for coal) : I ' Ecrude - Btu s of crude Oil and natural gas from the well head (also based on the higher heating values of crude oil and natural gas) E . E The Btu equivalent for kwh of electricity electric a E The product of the percentage of electricity not produced from fossil fuels (i.e., from hydroelectric and nuclear fuels) and the combined heat rates of the hydroelectric and nuclear systems if replaced by the fossil equivalents. The Bureau of Mines uses the value of 0.6165 for a (5). Notice that this definition of an energy equivalence Places a zero value on energy from human labor. At first, this may seem to be erroneous. Energy analysis is the accounting of the energy required to perform all acts for a particular process which would not normally be done if the process were not in existence. The argument is made that human consumption of energy would not change whether the process were in existence or not. This statement is 20 clearly correct if we consider the role of humans in society. All industrial processes are ultimately in existence for human consumption either directly (such as foods) or indirectly to raise the standard of living for humans (such as housing, transportation or even environ- Viewed in this mental controls or wildlife preservation). light, any feedback of human energy to society is indeed a "free" energy form. Input-Output Analysis The first application of input-output theory to 'the United States' economic structure used the 1963 data arui the energy intensity coefficients were determined by Wright (4) . The method was then applied to data of the yenars 1963 and 1967 by Bullard and Herendeen (11) including several modifications of the data (to be discussed shortly). Priesently, the energy intensity coefficients generated by IBUJJlard and Herendeen at the Center for Advanced Computation, University of Illinois, for the year 1967 are those in use- The same group at the Center for Advanced Computation is now calculating the coefficients for the 1972 data, to be Published in the summer of 1980. An excellent review of input-output theory has been prePared by David Reister, Institute for Energy Analysis, Oak Ridge University (2) . The method may be thought of as a process analysis of 357 separate sectors based on ‘national average interactions. The trajectories of each 21 system are represented by a 357 x 357 matrix whose elements, X , correspond to the amount of product from sector i ij required to produce the gross output of sector j. Thus, 357 Z Xi' i=1 3 ‘to produce the gross output of sector j. is the total requirement from all sectors required The producing :sectors can be separated into energy and non-energy groups. (Fhe energy producing sectors are coal, crude oil and Iiatural gas, petroleum products, electric utilities and ggas utilities, and are designated as the first five sectors. {The energy production sectors require energy extracted from tihe earth, designated as Ek (k = 1,2,....,5). An energy kxalance may now be defined which states that the energy enfixodied in the output of a sector is the energy embodied irl inputs from other sectors, the energy extracted from the: earth and the energy embodied in the value added to the: output of that sector as shown schematically in Figure 2.2. Where : represents the energy embodied in a unit output h €ki 0f the ith sector of the kt is defined energy form. Eki as tfiie energy intensity coefficient. X. represents the gross output of sector j. V. represents the energy embodied in the value 3 added to the output of the jth sector. The element Vj is included because the value added 13 that included in the interaction matrix xij’ and 22 represents inputs such as land, labor, capital and employee compensation. Of the values added, capital is a valid energy input. The capital value added is reported in terms of purchases from the 357 sectors. 35 = Z i= 7 Vcap,j 1 Ski xcap,ij 3EY7 Z 8 .X.. e .X. i=1 kl ij k] 3 $ Ekj (k=l,2,...,5) Figure 2.2. Definition of the energy balance used in input-output analySis 23 The capital investment can be incorporated in the inter- action matrix by the appropriate modification of the interaction matrix elements. xij = Xij + Xcap.ij In order to calculate the energy intensity coefficients Eki' the elements Xij are assumed to be a function of Xj as follows: Xij = bij + aij Xj where: bij 5 fixed investment aij E marginal investment The current practice (as used in calculating the 11967 energy intensity coefficients) is to neglect the bij's arud assume the required input is directly prOportional to time output. This is recognized as a poor assumption when dealing with industrial-type producing sectors and may iJTtrnoduce uncertainty in the results. The energy balance may now be written as: 357 ..= .+ Ck] X:J Ekj 1:1 Ekl all Xj Another modification of the data is required. The (“IPENJt of sector j includes the amount of the products of sector j that are imported (designated as Pj) . Since no datii are available regarding foreign economic structures, time imported output of sector j is ignored by subtracting 24 Pj from Xj' All imported products are assumed to have the same energy intensity as their domestic counterparts. The energy balance m§y7now be written as: . X.-P. =E . + Z . .. .—P. k1 ( J 1) k1 i=1 8In all (X) 3) E (or in matrix notation for a specific energy form k: a (£2) = E + 2 a. (re) vehere: é-g E a diagonal matrix whose elements are ij-ij E E a 357 x 1 row vector with one non-zero element in one of the first five columns corresponding to the energy form under consideration It'll II 5 {(r-g) - g(X-§)} E: |m ,4.“ H l m |l>'< Hm H—I Noting that the kth energy form extracted from the earrth is the output of the kth sector (i.e., E = g_(;-;) Where 3 is a 357 x 1 row vector with unity as the only non— h zerr: element in the kt position, k = l, 2, 3, 4: 5) the energy balance may be written as: 2 (3'8) = g {(i-a)(x-g)} ( ) )-1 S: |m "H Hm In =g( "H No The energy intensity vector, 5, is calculated for eacri energy sector resulting in a 357 x 5 matrix of energy intensity coefficients, Eki' The five coefficients for eacfll sector are then summed into a single primary energy intlensity coefficient. +6 I = + O 0 8primary Ecoal crude o”:electriClty 25 The definition of primary energy is the fossil fuel equivalency of the energy consumed by the United States. This definition does not differentiate between renewable and non-renewable energy resources. However, the contribution by renewable energy sources is not a significant fraction of the energy consumed. Thus, the 'use of primary energy as the energy equivalence is acceptable .at this point in time. If alternative energy supply systems such as solar and nuclear energy do begin to contribute significantly to the supply of energy to the United States, -the»energy producing sectors will need to be expanded to :anlude possibly solar energy and uranium (nuclear energy) eruergy supply sectors. Ideally, the categorization of the ecxonomy into producing sectors should be absolutely com- prwehensive in the energy supply area. In that situation, elxectricity consumed would not represent any energy con- suunption not included in the other energy sectors (since elenetricity is not an energy resource), and the need for the a term would be eliminated. The data generated by the Department of Commerce is Imot in a form immediately useful for energy analysis purposes, as indicated by the modifications to account for caFNital and imported goods. Other potential limitations ofthe energy intensity coefficients obtained from input- on“iput theory, which result from the conventions used in cmmputing the data base, are as follows: 26 l. The data base is subject to inaccuracies from lack of complete coverage of an industry, restriction of data for proprietary reasons, and the use of data represent- ing slightly different time periods in the interaction matrix for various sectors. Furthermore, errors in the interaction matrix Q may generate disproportional errors in (L-g)-l. In short, it is not known if the data accurately represent the interactions of the 357 producing sectors. 2. The use of dollar flows to describe physical material flows may not be acceptable. In economics, it is well known that there are human values and other intangibles 'that influence prices of items that in no way reflect the Ighysical inputs to the production process. To assume that Chollar flows accurately represent energy flows is not reason- alale. There exist examples of similar items having widely vrirying energy intensities with no physical basis for the dis- anepancy. This has been dealt with for the five energy sec- tors by replacing dollar interactions with Btu interactions With data obtained from the census of Mineral Industries for 1967 (7) . 3. A major problem with input-ought methodology is ‘the inability of the coefficients to change with time ‘Vitfluout continually generating a completely new set of co- efficients from an up to date data base. As stated before, the data base is generated every five years (1963, 1967, 1972, etc.). However, it has typically taken the Department of Commerce six or seven years to publish the tables after the data base year. The coefficients presently used are 27 based on the 1967 census and are now thirteen years out of date. The coefficients based on the 1972 census will be available in 1980 and will immediately be eight years out of date. Typically, this problem is dealt with by employing price indices for the specific sector. Up to the year 1974, the recommended deflators are taken from a 1975 study jpublished by the Bureau of Labor Statistics (8). Included in the study are detailed price indices for a 129 sector (economy for the period 1958 to 1974. For 1975 and subsequent jyears an annual Bureau of Labor Statistics publication is tised, Wholesale Prices and Price Indices, Supplement 1976, IJata.for 1975 (now titled Producers Prices and Price Indices fcn: 1977 and following years) (9). Table 9 of this publica- tixon provides average price indices for SIC industries and Table 10 provides data for selected census product classes. Frtnm these two tables, price indices for either the exact indhastrial classification or a suitable similar classifica- ticui can be found excluding transportation, trade, construc- ticui and business and professional services sectors. Price ilkiixzes for services and structures are found in the Survey Of (Turrent Business, Table 21, for the appropriate year (10). Aside from the use of price indices, there are two Other methods suggested for "updating" the 1967 energy coef- ficxients. The Bureau of Mines annually publishes energy conSumption statistics for the United States. Included is tiue total amount of primary energy consumed in the United States during the year under consideration. The ratio of a... "4 .A b- “A. ..~ ‘3’ 28 the total primary energy consumed and the Gross National Product (GNP), which is the total output of all producing sectors or total sales to final demand, represents the national average of primary energy embodied per dollar spent for the year the data represent. If this ratio is known for both 1967 and the desired year, a correction can be uniformly applied to all sectors. This can also be thought of as applying a single price index based on current energy consumption. The final method suggested is to modify the 1967 interaction matrix and then generate a inew'set of coefficients for the desired year. It is ineasoned that the sectors most likely to change rapidly arms the energy sectors, coal, crude oil and natural gas, reafined petroleum, electricity and gas utilities. Sufficient arunual data can be obtained from the Bureau of Mines to up- derte these five rows of the transaction matrix (as was orig- irually done to change from dollar to Btu interactions) allowing the calculating of new energy coefficients. The 1963 data were adjusted to the year 1967 accord- inSI to the three methods suggested and the generated energy intensity coefficients were compared to the coefficients generated from the 1967 data (6) . The use of the price indices (either separate indices for each sector or a single ifulexfl were shown to update the 1963 coefficients poorly. HcDwever, modifying the energy rows of the interaction matrix was shown to yield fairly accurate updated coefficients. 29 4. As mentioned previously, the energy intensity coefficients are based on producer's prices. However, most often cost data for industrial processes are based on purchaser's prices. Therefore, trade and transportation costs must be subtracted from the purchase price and transferred to the corresponding sector as a separate required purchase. In preparing the 1967 I-O tables, trade (wholesale, retail and insurance) and transportation (rail, motor, water, air and pipeline) margins were estimated for purchases by each sector from all 357 sectors plus ten types of final demand. Thus, each sector has 357 sets of trade and transportation margins for purchases from other sectors, and another ten sets of margins for sales to final demand. Clearly in energy analysis, purchased equipment and materials could be sold to other sectors (i.e., the construction sector) or to final demand, and judgement must be used in choosing the proper margins. (Note: The average margins for sales to final demand are published along with the coefficients and the detailed margins are available on tape from the BEA.) Since updating the margins could be quite difficult, it is recommended to first deflate or inflate the cost data, then correct for trade and trans— portation. 5. As indicated, imported products are assumed to have the same energy intensity as their domestic counterparts. Imports which have domestic counterparts are referred to as competitive imports. However, directly allocated imports 30 (those which have no domestic counterpart) are also ignored in the interaction matrix and, therefore, have no associated energy intensity coefficients. This presents no significant limitation to the methodology since the amount of directly allocated imports to the United States is small. 6. The method is not capable of accounting for secondary products of the producing sectors. The problem arises when an establishment produces, as a secondary product amounting to less than 50% of total sales, the primary product of another sector. Consider an establishment whose primary output is primary aluminum which also produces aluminum castings as a secondary product. In the inter- action matrix, the aluminum castings are treated as a fictitious sale to the aluminum castings sector, thus accred- iting the primary aluminum sector for the sale as part of its gross output. The sale is then transferred to the gross output of the aluminum castings sector without transferring any of the corresponding inputs. Two sectors have now been accredited for the output of the same volume of product without increasing the input requirements of the aluminum castings sector. The energy intensity coefficient for the aluminum castings sector will now be smaller than it should actually be. This cannot be corrected for since the inputs responsible for the secondary product production are not known. Furthermore, even if the correct inputs could be identified and transferred, they do not represent the 31 necessary input as required by the sector the inputs are to be transferred to, to produce the same volume of product. 7. The manner in which the economy is disaggregated into the 357 producing sectors is not optimum for energy analysis purposes. For example, the dairy industry has been delegated 22 producing sectors, where the inorganic chemical industry is delegated a single sector. The classification assumes all products of the inorganic chemical industry have the identical embodied energies. Considering all the necessary modifications and inherent assumptions associated with the use of the economic input-output data to generate the energy intensity coef- ficients, the accuracy of the coefficients is suspect. In some instances, the lack of detail in the available data does not allow any meaningful use of the 357 sector level of dis- aggregation, denying exploitation of the method's greatest advantage. Thus, the need exists for another approach to analyzing the second and higher levels of energy analysis that could find use as a check on the input-output method as well as an Option to input-output analysis when the data will not allow proper use of the level of disaggregation. An alternative approach is to treat the economy as a single sector, with a single total energy consumption and total dollar output for the specific year in question. The total primary energy consumed (12) divided by the gross national product of the United States (13) for various years is used as the single sector energy intensity coefficient. The single 32 sector energy coefficients for the years 1960-1978 are listed in Table 2.1. Table 2.1. Total primary energy consumed per dollar spent for 1960-1978. Year E/GNP (Btu primary consumed) ( dollar spent ) 1960 87,512 1961 85,983 1962 83,527 1963 82,303 1964 80,281 1965 77,369 1966 74,303 1967 72,906 1968 70,956 1969 69,343 1970 68,017 1971 64,228 1972 61,165 1973 57,102 1974 51,207 1975 46,252 1976 43,457 1977 40,517 1978 36,666 The use of this ratio has the advantages of represent- ing the energy embodied per dollar purchaser's price for the specific year in question without any modification of the cost data. Both approaches to estimating the second and higher levels of energy analysis will have appropriate applications not only as a function of the data available, but as a function of the characteristics of the system as well. For example, in systems in which the dominant inputs are associated with extraction and delivery of the feed, such as fossil fuel 33 based systems, the energy embodied in the capital of the system is probably best estimated from the single sector energy intensity coefficient. However, when dealing with systems in which the capital energy investment dominates, such as a central receiver solar thermal power station, the use of input-output analysis is more appropriate. CHAPTER 3 APPLICATION Energy_Ana1ysis Applied to Industrial Processes Data Required Data concerning the construction, operation and maintenance of an industrial process are required in order to estimate the energy embodied in the inputs and outputs of that process. The data usually originate from an engineering process design in the following forms: 1. Process flow diagram including material and energy (thermal and electric) flows 2. Economic evaluation of the process including: i. Capital investment for purchase and instal- lation of materials and equipment, and construction of buildings and general facilities ii. Operation and maintenance costs 3. General and technical description of the process The accuracy of the energy analysis is directly dependent on the accuracy of the design data. Thus, the selection of an accurate and competent process design is necessary in order to perform an accurate energy analysis. The processing units included in the process design define the first level of energy analysis and the 34 35 data contained in the design quantitatively determine the inputs and outputs of the first level of energy analysis. In general, the inputs to the first level of energy analysis are categorized according to the producing sectors of the Standard Industrial Classification (1). This portion of the analysis is referred to as process analysis. The energies embodied in the inputs are determined by input- output analysis. The application of input-output analysis requires the inputs of the first level of energy analysis to be represented in a specific form (i.e., the data describing the inputs must be of a specific nature). An input can be categorized as either an energy input or as a material input (referred to as a non-energy input). Energy inputs must be expressed as either the thermal energy content of one of the following energy fuels: 1. delivered coal 2. delivered crude oil or natural gas from the well head 3. delivered petroleum products (i.e., after refining) 4. natural gas distributed by a gas utility or as electricity distributed by an electrical utility. Note that input-output analysis cannot be used to determine the energy embodied in a Btu of process heat. The energy inputs of the system are referred to as the utility require- ment of the system. 36 The material inputs (referred to as the raw material and capital requirements of the system) must be expressed as a dollar cost defined at a specific point in time (for example, 1977). In general, dollar costs of a material can represent either a producer's price (defined as the cost for the non-distributed product) or a purchaser's price (defined as the cost for a distributed product which includes the cost of the product itself, trade services and transportation requirements). Input-output analysis allows the conversion of the producer's price, expressed in 1967 dollars, of a product that can be represented by a producing sector listed in the SIC code (1), into a quantity of a specific form of energy with the use of an energy intensity coefficient. If the material is represented by a purchaser's price, the cost is separated into the producer's cost, trade cost and trans- portation cost through the use of trade and transportation margins. (Refer to the sections on application of process analysis and input-output analysis for details of these operations.) Thus, the specific year that the cost repre- sents must be known in order to select the apprOpriate price index to inflate or deflate the cost to 1967 dollars, and whether the cost is a producer's or purchaser's price must be known to allow the application of input-output analysis to non-energy inputs. The data describing the energy inputs and outputs of a system refer to the energy inputs and outputs for the 37 lifetime of the system. However, it is common to express utility and raw material requirements in annual rates and to amortize the capital requirement over the lifetime of the process. Definition of the Nameplate Processing System In general, the nameplate processing system refers to a subset of processing units of the entire system which are responsible for the major products of the system. For example, the nameplate processing system of a coal gasifi— cation system would center around the processing units that convert processed and delivered coal into high Btu pipeline gas. However, the nameplate processing system is not confined to this subset of processing units and it is advisable to expand the nameplate processing system to include as many processing units of which the design details are known. A common example of an expansion of the name- plate processing system is the inclusion of on site utili- ties generation processes. In order to expand the nameplate processing system, the system design must include facilities required for the transport of materials and energy between the processing units (i.e., pipelines, conveyor belts, small industrial motor vehicles, etc.). If the transportation system between the nameplate process system and the processing unit which is proposed to be included in the nameplate processing system unit is not specified in the design, the 38 expansion is not acceptable and the processing unit must be considered in the second level of the analysis. Determination of the Energy Inputs and Outputs of the System The general approach to the determination of the energy inputs and outputs of a system is outlined in Chapters 1 and 2. This section deals with the specifics of the application of process analysis, input-output analysis, and if required, the disaggregation of the energy intensity coefficients in the determination of the energy inputs and outputs of a system. The objective of this section is to provide a specific step by step procedure for an energy analysis which can be applied consistently to any system. Application of process analysis In the context of the approach to energy analysis presented in this study, process analysis is the quantitative determination of the raw materials, capital and energy flows into a system and the product flows out of a system. Process analysis requires the precise definition of system bound- aries. Once the boundaries are set, the amounts and forms of the inputs and outputs of the systems are either taken directly from the system design or estimated through the use of the disaggregation of energy intensity coefficients. The material and energy flows of an industrial process are generalized as shown in Figure 3.1. 39 feed t___. b rimar roduct . Nameplate p y p capital Processing I secondary products raw material System utilities _ waste products General Facilities Figure 3.1. Generalized material and energy flows of an industrial process Using Figure 3.1 as a model, a checklist of energy inputs for the first level of energy analysis of a general- ized industrial process can be generated as listed in Table 3.1. The inputs refer to the lifetime requirements of the system but it is acceptable to report the energy and raw material inputs per unit time (usually years) and amortize the capital energy inputs over the lifetime of the system. The term "required" energy represents all direct energy usage, energy embodied in materials used, and a por- tion of the energy embodied in equipment used based on the fraction of the equipment's useful lifetime depleted. Note that, even though the general facilities of the system do not produce any useful products, they are necessary for the operation of the system and are therefore valid energy inputs. 40 Table 3.1. List of energy inputs to the first level of energy analysis of a generalized industrial process 1. Primary energy embodied in the nameplate process equipment and materials 2. Primary energy required for the distribution (i.e., sales and delivery to nameplate process site) of the nameplate process equip- ment and materials 3. Primary energy required for land preparation, required on site assembly and construction, and installation of nameplate process equipment and materials 4. Primary energy embodied in feeds, raw materials and utilities 5. Primary energy required for distribution (i.e., sales and delivery to nameplate process site) of feed, raw materials and utilities 6. Primary energy required for distribution of primary and secondary products 7. Primary energy required for disposal of waste products 8. Primary energy embodied in the general facilities 9. Primary energy required for the distribution of the general facilities 10. Primary energy required for land preparation, required on site assembly and construction, and installation of general facilities 11. Primary energy required for the maintenance of the nameplate process equipment and materials, and general facilities Note that energy inputs 1-3, 8-10 and 11 represent the capital energy investment. 41 To complete the first level of energy analysis, the energy outputs of the nameplate processing system must be determined. However, there is not uniform agree- ment as to the definition of an energy product. The convention adopted for this study characterizes energy products according to the end use as a supply of useful energy to society. This definition includes all products that are either consumed in the production of work or pro- duced directly as heat or other forms of energy. Examples of energy products are fuels, foods (human and animal) and electricity. If the product is considered to be an energy product, its energy content is taken as its higher heating value. Notice that this definition of embodied energy is fundamentally different than that of the inputs. This is consistent with the definition of the net energy of systems as the energy available for use by society after deducting all the energy required to construct, Operate and maintain the energy supply system (not including the energy content of the energy resource utilized). Thus, a product may contain embodied energy by virtue of its manufacturing process, which must be considered if the product is used by a system, while it may not have any useful energy content. For example, petroleum products have an energy subsidy of 0.2157 Btu primary energy for every Btu of useful thermal energy content. At this point of the analysis, it is useful to develOp the horizontal trajectory of the nameplate 42 processing system. Recall that the horizontal trajectory of a process is a tracing back of all processing systems required to produce the delivered feed of the process from raw materials and energy resources extracted from the earth. It is advisable to extend process analysis along the hori- zontal trajectory from the delivered feed back to a point at which the remaining trajectory is well represented by national average production. Since the feed is the major material flow (excluding the possibility of capital) into the nameplate processing system, the transportation step (and perhaps the processing step) immediately preceding the nameplate processing system could represent major energy inputs. These process units are generally extremely site specific and often require extension of the process analysis. For example, consider the horizontal trajectory of coal gasi- fication (Figure 3.2). As indicated by dotted line, the nameplate processing system begins with the processing of delivered raw coal. In general, national averages estima— tion of the transportation requirement (module B preceding module C on the horizontal trajectory) is not adequate requiring extension of process analysis. Before the application of process analysis is com- plete, the raw materials, utilities and capital inputs to the nameplate processing system must be examined to determine if the specific inputs are the products of one of the 357 producing sectors for which energy intensity coefficients have been determined. If this is the case, the process 43 Emumwm mcwmmwooum mumHQmEmc an omnwsvmn mamflumume 3mm mesa nouns 3mu mumummo on oommnousm suaveuuomam muoscoum mamas muUSUOMQ ammocoomm mom oceammflm sum noes Hmoo woman ca mcflaocms suppose mamas process 1primarylproduct .- muUDUOHm Hmuwmmo cam mumccooom mamwumume 3mm muosooum mofluwafius mumm3 feed camrdhaxsq 2 coeusnwuumwo pom oceaccmc uosooum mumccooom cowumumcom mmwuflaflus cofluMmewmmm Hmoo mcflmmmooum Hmoo Godusnwhumwo pom mcwapcws muosooum ceases Hmoo N.m gunmen 0» mos g. .- waste roducts secondary products P 1e _fimmmooum .JWsooum wumeHQ comm utilities raw materials and capital nun DOV-Ilka zuouommmue coflumofluflwmw Hmou .N.m choose 45 analysis is complete and input-output analysis can be applied. If any of the inputs are not represented by one of the 357 producing sectors, process analysis must be extended along the vertical trajectory of each input not represented by one of the 357 producing sectors. Extension of process analysis back along vertical trajectories replaces the inputs that are not represented by a pro- ducing sector with additional inputs of raw materials, utilities and capital. The process analysis must be extended until the additional inputs are represented by producing sectors. The extension of process analysis along either a horizontal or vertical trajectory is accomplished by identifying the system responsible for production of the inputs not represented by a producing sector and applying the same procedure outlined for the application of process analysis to the nameplate processing system. However, data describing the systems to which the process analysis is to be extended to is often not available. In these cases, the disaggregation of the energy intensity coefficients can be used to estimate energy inputs for which no information is available. (See use of the disaggregation of energy intensity coefficients.) cu :1 (EV hm» 46 Application of input-output analysis Comments There are two modes of input-output application, the 357 sector disaggregation level and the single sector disaggregation level, as indicated in Chapter 2. The mode of application used is up to the discretion of the analyst and depends on the detail of the available data and the characteristics of the system (usually concerning the capital investment of the system). There are two independent points that influence the mode of input-output application chosen. These are: 1. When should the 357 sector disaggregation level be used? The question is answered by the characteristics of the system with regard to the capital investment. If the energy input resulting from the capital investment is thought to be a significant portion of the total required energy input of the system, the 357 sector disaggregation level is appropriate because it offers more information about the capital energy inputs. 2. When can the 357 sector disaggregation level be used? The available data determine the answer to this question. The data, usually the data describing the capital investment, should be of sufficient detail to allow signifi- cant use of the level of sector disaggregation in order for the use of the 357 level of disaggregation to be worthwhile. A\u NA " V4 P I 5: Po “J t >4 5» 47 Single sector disaggregation level application of input-output analysis This application employs the direct use of the E/GNP coefficients given in Chapter 2. However, the required input data are of a different nature than that required by the 357 level application. The single sector coefficient represents the primary energy embodied per dollar spent (according to national averages) for a specific year. Thus, the input data should represent the entire dollar expenditure of the system (including labor). This is a sharp contrast to the nature of the data required for the 357 level of analysis which should include dollar expenditures for materials, energy forms and equipment (not labor) that must then be separated into producer's costs, trade costs and transportation costs. 357 sector disaggregation level application of input-output analysis As indicated in the data required section, quantities of energy flows into the system must be in the form of the thermal energy content (or the thermal energy equivalence for electricity) of an energy product from one of the five energy sectors and the quantities of non-energy flows into the system must be in the form of dollar costs at a specific point in time. Furthermore, the type of energy inputs represented by the dollar costs must be known (i.e., do the costs represent producer's or purchaser's prices). Thus, the first step in the application of input-output analysis Fit A!» Q l 5 . :n ‘ Us .\~ .— \ 48 is the organization and modification (if necessary) of the input quantities of the system thataue required to assemble the data in the proper form. Once the input data are assembled in the proper form, they must be assigned to the producing sectors that produce the specific products. Descriptions of the I-0 sectors and a listing of their products are found in the Energy Analysis Handbook (2) and the Standard Industrial Classification (1). It is suggested that the analyst familiarize himself with the sector's descriptions and products before attempting an analysis. Table 3.2 lists common industrial equipment and the corresponding producing sectors. It should be noted that the input-output code varies from the energy intensity coefficient sectors to the economic input-output sectors. The correlation between the codes is given in the Energy Analysis Handbook (2). Recall that the present energy intensity coefficients apply to the year 1967. Thus, the inputs given in the form of dollar amounts must be either inflated or deflated to the year 1967. This is done using the price index of each specific sector. The sources of the suggested price indices are given in Chapter 2. Next, trade and transportation requirements are esti- mated for the system inputs. As indicated in Chapter 2, the economic structure of the United States consists of inter- action data between 357 divisions (sectors) of the economy. ,. Id . a“: -‘L 49 Table 3.2. List of industrial sectors responsible for production of common industrial equipment (2) Sector Products 4006 Boiler shop products heat exchangers 4901 4903 4906 4907 4806 4208 pumps and compressors blowers and fans industrial furnaces and ovens general industrial machinery special industrial machinery pipes and valves condensers boilers metal columns for distillation, absorption, etc. metal tanks and vessels (reactors) pumps compressors industrial fans and blowers heat collectors, air washing and air purification equipment electrical furnaces and ovens fuel fired furnaces and ovens high frequency induction and dielectric heating equipment no subclassification chemical manufacturing indus- tries' machinery, equipment and parts pipes valves 50 Each sector acts as a producing sector (the sector produces products that are consumed by the consuming sectors or various types of final demand) and as a consuming sector (the sector purchases products from the producing sectors). Note that a sector may consume some of its own product. A portion of the interaction data are the dollars spent for trade (wholesale, retail and insurance) and transportation (rail, truck, pipeline, air and water) for the purchases of a consuming industry from the producing sectors. Since the dollar amount spent by the consuming industry for the purchase of a product (excluding the trade and transportation costs) from a producing sector is known, percentages of the total dollar transaction between consuming and producing sectors (either including or excluding trade and transportation costs) spent for trade and transportation can be generated. These percentages are referred to as trade and transportation margins. Thus, it is possible to generate 357 sets of trade and transportation margins (one for each producing sector) for each of the 357 consuming sectors. Furthermore, there are data of dollars spent for trade and transportation for the purchase of products by various types of final demand. Thus, trade and transportation margins for sales to final demand can be generated. The trade and transportation mar- gins for sales other than to final demand were generated by the author for the 1967 input-output data and the margins for sale to final demand were generated at the Center for Advanced Computations, University of Illinois (2). The 51 use of trade and transportation margins are illustrated in the following examples: Case I - Energy product inputs The trade and transportation margins for sales of energy products to final demand have units of 1967 dollars per MM Btu energy content of the product. The trade and transportation margins for sales to final demand for the coal producing sector (sector 700) are listed in Table 3.3. Table 3.3. Trade and transportation margins for sales to final demand of the coal producing sector (2) I-O Trade Margins Transportation Margins Sector ($1967/MM Btu) ($1967/MM Btu) 6901 6902 7004 6501 6503 6504 6505 6506 700 0.0048 0.0277 0 0.0934 0.0186 0.01 0 0 The number labels given to the various trade and transportation margins are the input-output sectors that are responsible for trade and transportation. Table 3.4 lists the trade and transportation sectors. Consider, for example, a system that requires an input of 1 MM Btu from coal per year. The trade and transportation requirements, given in terms of dollar cost, are listed in Table 3.5. 52 Table 3.4. List of trade and transportation sectors (2) Segtor Sector Descriptions 6901 wholesale trade 6902 retail trade 7004 insurance 6501 rail transportation 6503 truck transportation 6504 water transportation 6505 air transportation 6506 pipeline transportation Table 3.5. Total requirement for delivery of coal input I-O Required Input Sector ($1967/year) 6901 0.0048 6902 0.0277 7004 -- 6501 0.0934 6503 0.0186 6504 0.0100 6505 -- 6506 -- .. an. .c» .nu 2 6.4 R\~ 53 For energy product sales to end uses other than final demand, the margins have units of percentage of dollar cost of product (either producer's or purchaser's price) and are applied as illustrated in Cases II and III. Cases II and III are different applications of the same margins for non-energy products. Case II represents the use of margins on purchaser's prices and Case III represents the use of the margins on producer's prices. For example, consider the non-energy product of boiler shOp work, sector 4006. Trade and transportation margins for sales to final demand for the purchases of products from sector 4006 are listed in Table 3.6. Table 3.6. Trade and transportation margins for sales to final demand for sector 4006 (2) I-O Trade Margins (%) Transportation Margins (%) Totals Sector 6901 6902 7004 6501 6503 6504 6505 6506 % 4006 4 0 0 l l O 0 0 6 f Note: All non-energy product margins listed in this report are percentages of the purchaser's price. Case II - Non-energy product input of 1,000,000 1967 dollars producer's price Since the margins are percentages of the purchaser's price, the producer's price is modified to represent the purchaser's price then the trade and transportation costs are determined. The producer's price is 94% of the purchaser's price according to the total margin percentage in Table 3.6. wu—N‘fi 54 Thus, the purchaser's price is 1,063,830 1967 dollars. The calculated trade and transportation costs are listed in Table 3.7. Case III - Non-energy product of 1,063,830 1967 dollars purchaser's price If the inputs are expressed in terms of purchaser's prices, the application of the trade and transportation margins are straightforward. Given a purchaser's price of 1,063,830 1967 dollars, use of the margins in Table 3.6 yield a producer's price of 1,000,000 1967 dollars and the trade and transportation costs listed in Table 3.7. Case IV - Inputs (energy or non-energy) reported as producer's costs and transportation requirements The trade and transportation margins are intended for use in the absence of more site specific data. Specific data regarding the trade and transportation energy require- ments of a product usually offer information dealing with the transportation of the product. Transportation data may appear in two forms. One form is referred to as a transportation requirement and consists of a weight to be transported over a distance and the specific form of transportation. Energy requirements per unit of transportation work (i.e., weight over a distance) have been determined for several forms of transportation (5). Thus, if the transportation requirement is known, the energy requirement for transportation can be determined. This approach to determining the transportation energy requirement is actually an extension of process jT—fi- \I ‘15 55 Table 3.7. Trade and transportation cost for a non-energy product input from sector 4006 of 1,000,000 $1967 producer's cost and 1,063,830 $1967 purchaser's cost I-O Required Input Sector ($1967éyear) 6901 42,554 6902 —- 7004 ~- 6501 10,638 6503 10,638 6504 -- 6505 -- 6506 -- Totals 63,830 Note that the total cost for trade and transportation difference in the purchaser's and producer's prices. is the ~5- a. ~\V S 56 analysis to the delivery of the product, while the energy embodied in the non-delivered product is determined by input- output analysis requiring the cost data describing the non— delivered product to be the producer's price. Thus, this approach may require the use of trade and transportation margins to modify purchaser's prices. This approach is mainly utilized when the effect of transportation distances of inputs and/or outputs on the energy parameters of a system is to be evaluated. The other form of transportation data is a dollar cost of a specific form of transportation. This form of transportation data is available from design reports that present cost data of materials in components of the material and shipping and handling. The cost data components are assumed to represent producer's prices of the non-delivered product and required transportation. This data form allows the direct application of energy intensity coefficients after deflation of the cost data. In general, the energy requirement for trade is neglected when specific transportation dataanxeavailable, primarily due to the lack of available specific trade data. This is not considered to result in an underestimation of the energy embodied in the delivered product because trade is less energy intensive than transportation (as indicated by the respective energy intensity coefficients) and trans- portation energy requirements determined from specific data :u N» ,«u‘ i" t" .1: C» C; Q» 57 are usually significantly greater than trade energy requirements estimated from the margins. The choice of the proper trade and transportation margins (i.e., sales to final demand or to a consuming sector) is usually the intuitive judgment of the analyst based on knowledge of the system being analyzed. In gen- eral, sales made directly to the nameplate processing system (representing direct inputs of the first level of energy analysis) are considered sales to final demand. Indirect sales to the nameplate process (such as materials sold to the construction industry used to construct the system, or sales that result from the extension of process analysis to the second level of energy analysis) are usually considered sales to the intermediate sector. The energy intensity coefficients for converting dollar amounts (for non-energy products) and energy content amounts (for energy products) to primary energy amounts can now be applied to the input data. At this point, the data are in the form of energy content or 1967 dollars producer's costs of the input products, and 1967 dollars producer's costs for the estimated trade and transportation requirements or a transportation requirement (i.e., ton-miles) via a specific mode of transportation. The data are converted to energy inputs of primary energy by multiplying the data quantifying the input required from each sector by the energy intensity coefficient of that sector. 58 Use of the disaggregation of energy intensity coefficients D. Reister has published a disaggregation of the energy intensity coefficients of a 90 sector economy (3) (i.e., the disaggregation is performed on energy intensity coefficients obtained from an interaction matrix based on a 90 sector grouping rather than a 357 sector grouping of the economy). The disaggregation is a listing of the contributions to the total energy intensity of a sector (represented as a percentage of the energy intensity coefficient) from the other producing sectors. The percentage contributions are grouped into two main cate- gories, capital and non—capital contributions. The capital contributions list the percentages from the top twenty non- energy contributing sectors. The non-capital contributions list the percentages from the five energy sectors, and the percentages from the top twenty non-energy contributing sectors. Thus, the disaggregation of energy intensity coef- ficients represents a detailed energy analysis of the energy inputs per unit output of 90 systems (based on national average inputs and outputs). The utility of the disaggrega- tion of energy intensity coefficients for the purpose of approximating energy inputs of systems through analogies is enormous. For example, consider a system in which an energy input is not known due to the lack of data. By establishing an analogous system that is one of the 90 systems included 59 in the disaggregation of energy intensity coefficients (such as the gas utilities as an analogy to a coal gasifi- cation complex), an estimation, expressed as a percentage of the total energy input of the system, can be made for the unknown input. Also, estimations can be made of specific unknown portions of a given input by establishing an analogous system to the system that produces that input. Energy Analysis Results Reporting of results As indicated previously, the complete documentation of the methodology and calculations of the analysis is essential to the credibility of the analysis. However, the usefulness of the analysis is determined by how the results of the analysis are documented. Table 3.8 lists the informa- tion required to allow complete use of the results of an energy analysis. Energyyparameters Definition of energy parameters As a relatively new and developing science, research in the field of energy analysis has been mainly devoted to methodological approaches and, as a result, the area which deals with interpretation of the analysis has been neglected. Scientists involved with energy analysis traditionally define some parameter, useful for their own purpose, that they claim to be the end result of the analysis, and ignore other 60 Table 3.8. Suggested format for reporting of energy analysis results 1. Process description - A brief description of the technology base of the process along with characteristics of the process and the state of the feed to the process. 2. State of system outputs or products (waste, secondary and primary) - The word state is meant to indicate physical location and form as well as its quality. It is necessary to know where the products are, what form they are in and their energy content in order to draw comparisons with other processes producing similar products. 3. Breakdown of energy inputs - The inputs should be presented in groups as feed, utilities, raw materials and capital. 4. Breakdown of energy outputs - Each product that is considered an energy product should be reported separately with its energy value. HI (I) ~u A .0: fin '1 ‘1) EEC» ‘« 61 information that is essential in understanding the true energetic characteristics of the system under consideration. Thus, many conclusions can be drawn from a single analysis depending on how the analyst decides to manipulate the results of the analysis. Any conclusions drawn from an energy analysis should be based on a group of parameters. Certainly, for any comparisons to be made between systems on the basis of one parameter, the other parameters must be similar between the systems. Otherwise, the conclusions drawn from the comparison may be invalid. Therefore, the purpose of this section is to define a set of parameters that will provide a complete description of a system's energy characteristics. First, the energy flows of a system (see Figure 3.3) must be defined. Notice that all energy flows are rates with units of Btu primary energy/unit of time. This does not, however, accurately represent the real situation. The process may be thought of as a semibatch Operation where one invests subsidy one, the capital energy subsidy, all at once and then adds the other subsidies at a continuous rate for the lifetime of the process. For computational convenience, the capital subsidy is amortized into an annual rate over the lifetime of the process and is accounted for the same as any other subsidy. This aspect of the analysis gives rise to dynamic as well as time independent interpreta- tions of energy analysis results. The definition of the energy parameters useful in interpreting the results of an analysis are listed in Table 3.9. 62 Emumwm wammcm hmumcm an we mson zoumcm .m.m gunman e¢fi§$.flunbefificawmam..mw Eflfifimhwnnmflxnm“Hfifimmsfleoummmm...m enemtmrufiwasfixsem.HvumtmscRumfi enfisansmémee c mpnxmwu_awmafi_u __ m 1mm + mm + H9 enemas... 806 Enos .. we tfiimgawswaghwmmfifiquo.u m sonflafi.awmammfldahwsa_zsmu.m refineswmmfism.dflzdmu..a max muQfiM%mHan£hNfiH¥i .Lr . w J NHHLMHWMM .. . ERKSW .mw m QUMHQQHBZ ..Hm mag 05% 8HDM8H ) mafia cH J a u H mm mm Hm 63 Table 3.9. Definitions of energy analysis parameters Total Ener S b “d + + gy u 51 y (ST) S1 S2 S3 Net Energy EO-Sm Energy Gain (G) E /S o T Overall Process EffiCiency EO/Eearth+ST Resource Utilization Factor Eearth/Eo Capital Requirement Factor Sl/Eo One final parameter which is useful when comparing energy supply systems is the rated energy output. System designs are often influenced by the size of the energy supply systems and, as a result, the results of the energy analyses are influenced as well. Discussion of energy parameters Total Energy Subsidy - This value is the absolute energy cost of producing the energy output of a system. The total energy subsidy does not include the energy content Of the energy resource that is converted to a useful energy form (E ). earth Net Energy - This value is the amount of useful energy made available to society. Consider the following illustration: An energy supply system is given an amount of crude energy (resource) to convert to a useful energy form. During the conversion, process losses are experienced, and the 64 resource is reduced to the energy output of the system E0. Furthermore, the system requires an energy investment in order to operate (ST). The remaining energy that can be consumed by society is the net energy (BO-ST). Energy Gain - The energy gain is a measure of the energy cost to produce a unit output of energy (i.e., the relative cost of energy). The parameter is a useful comparison between energy supply systems in which the gross energy outputs and the resource utilization factors are similar. The comparison of energy supply systems on the basis of the energy gain alone can lead to inaccurate conclusions. The inadequacies of the energy gain parameter are illustrated in the following examples: 1. External supply vs. internal generation of utilities Consider the following systems shown in Figure 3.4 and Figure 3.5. 100 Btu Energy 80 Btu Supply 1.. System 1* r 10 Btu 2 Btu 2 Btu Utilities Capital Raw materials Figure 3.4. System with external supply of utilities 65 80 Btu 3 Btu 3 Btu Utilities Capital Raw Materials Figure 3.5. System with internal generation of utilities Table 3.10 lists a comparison of the energy gains, resource utilization factors, gross energy outputs and the overall process efficiencies of the two systems. Table 3.10. Comparison of energy parameters for systems with internal and external utilities supply Utility Gross Resource Energy Overall Supply Energy Utilization Gain Process Output Factor Efficiency (Btu) (Btu) (%) internal 80 1.40 13.3 67.80 external 80 1.25 5.7 70.18 A comparison of the energy gains alone would lead to the conclusion that the internal generation of utilities offersa significantly more efficient supply of energy. Upon examination of the overall process efficiencies, it is clear that this is an inaccurate conclusion. 66 2. Dominance of the total energy subsidy by a single module in an energy trajectory This phenomenon is illustrated by two trajectories (shown in Figure 3.6 and Figure 3.7) leading to the same end-use product. In Place . Resource Extraction 500 . 480 Btu __gld' use and gap—4' ProceSSlng 3 l Transportation u p 10 Btu 30 Btu energy energy subsidy subsidy Figure 3.6. Trajectory I In Place . Resourc Extraction 500 . 480 Btu .EPd use iH and. Btu II ProceSSing product Transportation 30 Btu 30 Btu energy energy subsidy subsidy Figure 3.7. Trajectory II 67 Table 3.11 lists a comparison of the energy gain as a function of position for each trajectory. Table 3.11. Comparison of energy gain and total energy subsidy as a function of position in the trajectory Extraction and Processing Transportation Energy Energy Energy Energy Trajectory Gain Subsidy Gain Subsidy I 50 _ 10 12 40 II 16.7 30 8 60 It is observed that the energy characteristics of feeds with vastly different energy parameters can be washed out by processing systems that have energy subsidies much larger than all modules in the trajectory. Intuitively, it is difficult to accept similar energetics of products produced from feeds of vastly different energetics. In this case, how- ever, the similar gains represent an accurate comparison of the systems. 3. Energetics of scale The energy gain ratio contains no information regarding the size Of a system. As in economics, the required energy inputs of a system are not proportional to the output of the system. This aspect of energy analysis must be considered when comparing systems which differ significantly in gross energy outputs. Overall Process Efficiency - This value is similar to a thermodynamic process efficiency including the total 68 energy subsidy in the energy flow into the system. This value is useful in comparing energy supply systems based on non-renewable vs. renewable (i.e., free) energy resources. Resource Utilization Factor - This value represents the quantity of resource (i.e., the resource that is being converted into a useful energy form) per unit of useful energy produced. Note that this value is not the total energy consumed per unit of energy produced. Also, note that this value is not necessarily the thermodynamic effi- ciency of the entire system since a portion Of the energy subsidy may be generated from the energy resource as well as being converted into a useful energy form. Capital Requirement Factor - This value represents the "capital" cost of energy per unit of energy produced. This value multiplied by the annual output and the lifetime of the system represents the total capital investment of the system that must be invested before the system can Operate (excluding a small annual maintenance energy included in the capital energy subsidy). The capital energy require- ment, the resource utilization factor and the energy gain are combined in a dynamic energy supply and demand model that can predict the dynamic behavior of energy supply systems. Example of Energy Analysis Application ‘Energy Analysis of a Coal Gasification Complex Comments The organization of this energy analysis serves as the outline for the other analyses performed by the author presented in this study. 69 Summary of Energy Analysis Description of Process The system is based on the process design of the Burnham Coal Gasification Complex assembled by the Stearn-Rogers Corporation for the El Paso Natural Gas Company (4). The system is designed to produce 288 MMSCF per day Of 954 Btu/SCF synthetic pipeline gas at an over- all load factor of 91%. The gas will be produced from 9,383,000 tons/year of Navajo coal with a higher heating value of 8664 Btu/lb using the Lurgi coal gasification, purification and methanation technology. Included in the complex is a utility plant for production of compressed air, high purity oxygen, fuel gas, cooling water, steam and electricity and a coal processing unit for the crushing and cleaning of the raw coal. Electricity is purchased for Operation of the raw water pump only. The secondary pro- ducts of the complex are listed in Table 3.12. The properties of the coal used as the feed to the system are listed in Table 3.13. The complex is to be located local to the coal mining Operation allowing a minimum coal transportation requirement. 70 Table 3.12. Secondary products of coal gasification process Higher (Useful Heating Energy Product Quantity (4) Value Content)(7) l Btu Tar 2 Eg— , 6 ___ 39,250 day 0 15 x 10 gal Tar oil 157,370 Ei— 0.15 x 106 953 day gal N th gal Btu ap a 74,900 337 5.248 x 1065—51- gal ____ Crude phenols 32,740 55? Elemental Sulfur 167 long ton —--- day Ammonia Soln. a1 (20 wt %) 332,550 g— ___- aY Table 3.13. Properties of Navajo coal (4) Proximate Analysis Weight % Dry and Ash-Free Coal 64.50 Ash 19.25 Moisture 16.25 Total 100.00 Component Analysis (D.A.F. Coal) Carbon 76.26 Hydrogen 5.58 Nitrogen 1.32 Sulfur 1.07 Oxygen 15.74 Trace Compounds 0.03 Total 100.00 Higher Heating Value 8664 Btu/lb Ash Softening Data Softening Point 22822F Melting Point 2597OF Flow Point 2723 F 71 State of system products Primary products The complex produces 288 MMSCF per day of a synthetic pipeline gas. The prOperties of the pipeline gas are listed in Table 3.14. Table 3.14. Properties of the synthetic pipeline gas (4) Component Volume % Hydrogen 4.16 Methane 92.93 Carbon Dioxide 1.81 Carbon Monoxide 0.01 Nitrogen and Argon 1.09 Total 100.00 Higher Heating Value - 8954 Btu/SCF The system design includes the transportation of the gas via pipeline for 7.3 miles, where it will join the El Paso Natural Gas Company's main line (already in existence). Secondary products The quantities and energy contents of the secondary products are listed in Table 3.12. The system design includes temporary tank storage of the secondary products and loading and unloading facilities for rail transportation. Waste products Liquid wastes are stored temporarily in tanks with facilities included for loading and unloading for rail transportation. Solid wastes (ash) from both air and oxygen m—mm. _. . 72 blown gasifiers along with refuse from coal fines cleaning are dewatered and transported to the mine area for disposal. Only facilities for transporting and handling of waste ash are included in the design. Actual disposal facilities are excluded. Water effluents from the complex are handled by either the general sewage system or by solar evaporation and settling ponds. Energy inputs and outputs of the system The breakdown of the energy inputs to the system are listed in Table 3.15 and the breakdown of the energy outputs of the system are listed in Table 3.16. Energygparameters The energy parameters of the coal gasification complex are listed in Table 3.17. Basis of Analysis General approach The system generates all the required utilities (with the exception of purchased electricity for operation of the river water pump) local to the main processing units. Thus, the utility generating units will be included in the nameplate processing system. The system is atypical in the sense that the nameplate processing system is local to the coal mining Operation. In general, coal gasification complexes require transportation of mined coal to the process site. Therefore, a fictitious 73 Table 3.15. Energy inputs of the system Input (x 10 Embodied Energy 9 Btu Primary/Year) feed (coal) energy content energy subsidy feed transportation requirement 0 mile distance 50 mile distance 100 mile distance 500 mile distance utilities purchased electricity capital — amortized over a 30-year complex life raw materials chemicals and catalyst 162,589 1,414 704 1,409 7,037 313 812 892 74 Table 3.16. Energy outputs of the system (4) Product Energy Content (x 109 Btu/Year) Pipeline gas 91,260 Tar 11,921 Tar Oil 7,841 Naptha 4,974 Total 115,996 75 noo.o oe.H mo.no mo.HH www.moa movoa oom hoo.o ov.H mm.mo hm.mm omH.HHH ovmw ooa noo.o oo.a nm.mo mo.mm Hom.HHH mmao om hoo.o ov.H em.mo Hm.mm mom.~aa Hmvm o pouomh Heuomm w Geno Amumswpm AxumeHm Amawzv ucmEonwDomm COHPmNHHeuD mocwfioflmmm mmumcm sum moa xv ppm mos xv wocmumwc Hmuwemu OOHDOmmm mmwmwwm wmumcm mewmncm coflvmuuommcmma HH 0 umz wouocm H o Hmuoe xmaoeoo coflmewwemmo Hmoo mo mpmumEMHmm woumcm .bH.m OHQMB 76 transportation requirement is added to the system, with the distance of transportation variable. Thus, the analysis requires process analysis of the nameplate processing system with the extension of the process analysis along the horizontal trajectory to include the transportation of mined coal (refer to the coal gasification trajectory shown in Figure 3.2). Description of data The data used to perform the analysis are contained in the coal gasification complex design developed by the Stearn-Rogers Corporation for the El Paso Natural Gas Company (4). The energy flows into the system, coal and electricity, are expressed in terms of Btu/year and kwh/year, respectively. The raw material and capital flows are expressed in terms of $1973/year and $1973/proc- essing unit, respectively. All dollar costs represent purchaser's prices of equipment and materials. Also, the detail of the data warrants the use of the 357 sector disaggregation level of input-output analysis. Definition of the nameplateyprocessing system The nameplate processing system is defined to include the processing units, all interconnecting facilities and required general facilities of the processing units listed in Table 3.18. Table 3.18. 77 List of nameplate processing units (4) \OCDQONU'IDWNH O. O. .0 .0. O wrap: IOFJO O 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. Gas Production Crude Gas Shift Conversion Gas Cooling Gas Purification Refrigeration Methane Synthesis Product Gas Compression and Dehydration Gas Liquor Separation Phenol Extraction Gas Liquor Stripping Lock Gas Storage and Compression Sulfur Recovery Fuel Gas Production Fuel Gas Cooling Fuel Gas Treating Air Compression Steam and Power Generation Oxygen Production Oxygen Compression Raw Water Treating Cooling Water System Miscellaneous Plant Utility System Ash Dewatering and Transfer River Water Pumping Plant Raw Water Pipeline Raw Water Storage and Pumping Mine Crushing and Screening Coal Storage Blending and Screening Coal Fines Cleaning Mine Ash Handling 78 Determination of Energy Inputs of the System Application of process analysis Quantities of inputs and identification of apprOpriate producing sectors Data are extracted from the design report which represents the required energy inputs outlined in Table 3.1. The data are assigned to the appropriate producing sectors and presented according to the energy inputs they represent. Energy Inputs 1 and 2 Table 3.19 lists the quantities and the appropriate input-output sectors for the purchase and delivery of the nameplate processing equipment and materials. Energy Input 3 The energy required for land preparation, required assembly and construction at site, and installation of the nameplate processing equipment is estimated using the disaggregation of energy intensity coefficients. Energy Inputs 4 and 5 Table 3.20 lists the appropriate input-output sectors and the required quantities of the utilities, feed, feed transportation requirement, and the dollar expenditure for the purchase and delivery of the raw materials. 79 Table 3.19. Quantities of energy inputs 1 and 2 (4) Processing Quantity I-O Unit ($1973) Sector Gas Production 37,510,000 4006 Crude Gas Shift Conversion 4,220,000 4006 Gas Cooling 4,440,000 4006 Gas Purification 17,060,000 4903 Refrigeration 5,270,000 4901 Methane Synthesis 11,710,000 4006 Product Gas Compression & Dehydration 3,300,000 4901 Gas Liquor Separation 3,270,000 4006 Phenol Extraction 3,790,000 4006 Gas Liquor Stripping 3,100,000 4006 Lock Gas Storage & Compression 1,110,000 4901 Sulfur Recovery 4,490,000 4006 Fuel Gas Production 12,540,000 4006 Fuel Gas Cooling 860,000 4006 Fuel Gas Treating 2,220,000 4903 Air Compression 13,310,000 4901 Steam & Power Generation 16,610,000 4301 Oxygen Production 14,550,000 4006 Oxygen Compression 4,250,000 4901 Raw Water Treating 3,700,000 4006 Cooling Water System 3,190,000 Miscellaneous Plant Utility Systems 3,350,000 4907 Ash Dewatering & Transfer 3,480,000 4907 River Water Pumping Plant 1,770,000 6803 Raw Water Pipeline 5,710,000 4208 Raw Water Storage & Pumping 880,000 4901 Mine Crushing & Screening 1,610,000 4502 Coal Storage, Blending and Screening 6,460,000 4502 Coal Fines Cleaning 1,900,000 4502 Mine Ash Handling 270,000 4502 Materials Initial Catalyst and Chemicals 4,010,000 2701 80 Table 3.20. Energy inputs 4 and 5 (4) Quantity I-O Input (Units/Year) Sector Feed (Coal) 162,589 x 109 Btu 700 Transportation a of Feed 0 0 ton-mi Process soa 469 x 106 ton-mi AnalYSls 100a 938 x 106 ton-mi 500a 4,692 x 106 ton-mi Utilities 9 (Electricity) 80.5 x 10 Btu 6801 Raw Materials Catalyst and Chemicals 3,520,000 $1973 2701 a - transportation distance 81 Energy Inputs 6, 7, 8 and 9 Energy inputs for transportation of primary and secondary products to end use and the disposal of waste products are included in the general facilities. Table 3.21 lists the appropriate input—output sectors and quantities for the purchase and delivery of the general facilities. Table 3.21. Energy inputs 6, 7, 8 and 9 (4) Quantity I-O Product ($1973) Sector Site Improvements 1,420,000 3611 General Plant Buildings 2,130,000 3610 Electrical Distribution 3,070,000 5308 Header Systems & Interconnecting Piping 4,540,000 4208 Evaporation & Settling Ponds 690,000 3611 Storage & Loading 1,420,000 4006 Product Gas Pipeline 280,000 4208 Energy Input 10 The energy input for land preparation, required assembly and construction at site, and installation of general facilities is estimated using the disaggregation of energy intensity coefficients. 82 Energy Input 11 The energy input for the maintenance of the nameplate processing equipment and the general facilities is estimated using the disaggregation of energy intensity coefficients. Extension of process analysis The analysis requires the extension of process analysis to the transportation of coal by rail. The analysis of rail transportation has already been performed and is reported to require 1,500 Btu primary/ton mi. (5). The energy requirements for the transportation of coal are listed in Table 3.22. Table 3.22. Energy requirements for the transportation of coal 1233352322?“ hesitate“ (ton—mi/year) (4) (x 10 Btu primary/year) (mi) 0 0 0 469 x 106 704 50 938 x 106 1,407 100 4,692 x 106 7,037 500 Application of input-output analysis Comments Note that separate accounts must be kept for energy inputs 1-2 and 6-9 (lifetime inputs) and the annual investments. 83 Deflation of cost data The deflation of the cost data from 1973 dollars to 1967 dollars is listed in Table 3.23 (lifetime energy investments)and Table 3.24 (annual energy investments). Table 3.23. Deflation of cost data (lifetime investments) I-O Purchasgr's Price $1973 (6) Purchasgr's Price Sector (x 10 $1973) $I967 (x 10 $1967) 2701 4.010 1.075 3.730 3610 2.130 1.304 1.633 3611 2.110 1.304 1.618 4006 105.090 1.261 83.339 4208 10.530 1.264 8.331 4301 16.610 1.271 13.068 4502 10.240 1.318 7.769 4806 3.700 1.303 2.840 4901 28.120 1.260 22.317 4903 19.280 1.260 15.302 4907 6.830 1.260 5.421 5308 3.070 1.147 2.677 6803 1.770 1.214 1.458 Table 3.24. Deflation of cost data (annual investments) Purchaser's Price Purchaser's Price Sector (x 10 $1973/year) $I967 (x 10 $1967/year) 2701 3.520 1.075 3.274 84 Modification of purchaser's prices into producer's prices of products, trade and transportation, and the conversion of producer's prices to primary energy The inputs expressed in dollar quantities represent purchaser's prices. All inputs, except inputs from sectors 3610 and 3611, are considered as sales to final demand. Inputs from sectors 3610 and 3611 (concrete bricks and concrete products) are considered as sales to the new construction industry, sector 1103. Table 3.25 lists the appropriate trade and transportation margins. Table 3.25. Trade and transportation margins I-O Transport (%) Trade (%) Sector 6501 6503 6504 6505 6506 6901 6902 Total (sales to final demand) (2) 2701 2 l O 0 0 3 2 8 4006 l l 0 0 0 4 0 6 4208 0 l 0 0 0 11 O 12 4301 0 0 0 0 0 1 0 1 4502 0 l 0 0 0 5 0 6 4806 0 l 0 0 O 4 0 5 4901 1 2 0 0 0 10 0 13 4903 0 l 0 0 0 7 0 8 4907 0 0 0 0 0 7 0 7 5308 0 0 0 0 0 3 0 3 6803 0 0 0 0 0 0 0 0 (sales to sector 1103) (8) 3610 0 1.43 0 0 0 17.86 1.43 20.72 3611 0 0 0 0 10.24 4.17 14.41 85 The modification of the purchaser's price into the producer's prices for the product, trade and transporta- tion, and the conversion of the producer's cost into primary energy are listed in Table 3.26 (lifetime energy investments) and Table 3.27 (annual energy investments). Table 3.26. Modification of purchaser's prices into producer's prices, and the conversion of the producer's prices into primary energy (lifetime energy investments) Producer's Price Embodied Energy I-O 6 Btu Primary (2) 9 . Sector (x 10 $1967) $1967 (x 10 Btu Primary) 2701 3.432 291,465 1,000 3610 1.295 148,220 192 3611 1.385 113,661 157 4006 78.339 111,172 8,709 4208 7.331 78,483 575 4301 12.937 74,377 962 4502 7.303 75,541 552 4806 2.698 63,177 170 4901 19.416 59,006 1,146 4903 14.078 66,579 937 4907 5.042 68,763 347 5308 2.597 63,182 164 6803 1.458 114,263 167 6501 1.131 92,917 105 6503 1.683 54,968 93 6901 9.215 37,501 346 6902 0.165 37,329 6 The energy embodied in non-delivered materials and equipment is 15078 x 10 9 Btu primary. 86 Table 3.27. Modification of purchaser's prices into producer's prices, and the conversion of producer's prices into primary energy (annual energy investments) Embodied Energy , . I-O Prodgcer s Price Btu Primagy (x 109 Btu Sector (x 10 $1967/Year) $1967 (2) Primary/Year) 2701 3.012 291,465 878 6501 0.065 92,917 6 6502 0.033 54,968 2 6901 0.098 37,501 4 6902 0.065 37,329 2 The energy embodied in non-delivered materials is 9 878 x 10 Btu primary/year. Estimation of trade and transportation costs for the energy product inputs and the conversion of the energy product inputs and the trade and transportation costs into primary energy The only energy product input requiring estimation of the trade and transportation margins is the purchased electricity. Table 3.28 lists the trade and transportation margins for purchased electricity for sales to final demand. Table 3.28. Trade and transportation margins (2) I-O Trade ($/MM Btu) Transportation (S/MM Btu) Sector 6901 6902 7004 6501 6503 6504 6505 6506 6801 0 0 0 0 0 0 0 0 87 Since the trade and transportation margins are zero, no modification of the purchased electricity data is required. The energy flows into the system, mined coal and purchased electricity, are converted into primary energy as listed in Table 3.29. Table 3.29. Conversion of energy flows into primary energy (annual energy investments) Embodied Energy I-O anntity Btu Primary/ (x 109 Btu Primary/ Sector (x 10 Btu/Year) Btu (2) Year) 700 162,589 1.0087 164,003 6801 80.5 3.8951 313 Note that the primary energy embodied in the coal (i.e., feed) includes 162,589 Btu energy content and 1414 Btu primary energy subsidy. The total energy subsidy of the feed is the 1414 Btu primary plus the transportation energy requirements. Use of the disaggregation of energy intensity coefficients Estimation of energy inputs 3 and 10 The estimation of the energy required for the instal- lation of the nameplate processing equipment and the general facilities is made by assuming an analogy between instal- lation and the new construction industry, sector 1100. Table 3.30 lists the disaggregation of the energy intensity coefficient for sector 1100. 88 Table 3.30. Disaggregation of the energy intensity coefficients for sector 1100 (3) Energy % of Total Energy Usage Requirement Direct 20.77 Capital 2.62 Materials 65.34 Transportation 2.31 Services 4.21 Trade 4.75 The estimation of the installation energy is made by assuming the energy embodied in the non-delivered materials and equipment of inputs 1-2 and 8-9 represent the material requirement of sector 1100. The installation energy is then assumed to be the remaining energy requirement. Table 3.31 lists energy inputs 3 and 10. Table3.31. Energy inputs 3 and 10 Energy Embodied in Non-delivered Energy Materials and Energy Inputs 3 and 10 Equipment Inputs (Installation (Inputs 1-2, 8-9) (1-3, 8-10) Energy) (x 109 Btu Primary) (x 109 Btu Primary) (x 109 Btu Primary) 15,078 23,076 7998 89 Estimation of energy input 11 The energy required to maintain the nameplate processing equipment and the general facilities is esti- mated by assuming an analogy between the coal gasification complex and the natural gas utility sector. The disag- gregation Of the energy intensity coefficient for sector 6802 reports that 0.08% of the total energy require- ment is for maintenance (3). It is assumed that the capital investment, which is 1.44% of the total energy requirement of the complex, requires the maintenance energy. Thus, the total capital energy requirement, including maintenance, is 1.52% of the total energy requirement of the complex (including the energy content of the feed) of which 5.26% represents the maintenance energy requirement. Table 3.32 lists the energy required for maintenance. Table 3.32. Energy input 11 Capital Energy Total Investment Capital Maintenance (Not Including Energy Energy Maintenance) Investment Requirement 9 9 (x 10 Btu Primary) (x 10 Btu Primary) (x 109 Btu Primary) 23,076 24,358 1,282 Determination of Energy Outputs of the System The outputs of the system are determined from the data in Table 3.12 and an energy content Of 954 Btu/SCF for the synthetic gas (gas production is 288 MM SCF/day). Table 3.33 lists the energy outputs of the system. 90 Table 3.33. Energy outputs of the system Energy Energy Output Product Quantity Content (x 109 Btu/Year) . . 10 SCF Btu Pipeline Gas 9.566 x 10 year 954 EEF 91,260 Tar 7.947 x 107 Gal 0.15x106 33% 11,921 year ga Tar 011 5.227 x 107 Gal 0.15x106 Btu 7,841 year gaI 7 Gal 6 Btu Naptha 2.488 x 10 year 5.248x10 EST 4,974 Total energy output 115,996 Note that the system products of crude phenols, elemental sulfur and 20 wt. percent solution of ammonia are not considered as energy products. One might argue that crude phenols are an energy product. However, the crude phenols will most likely be sold as feedstock to the chemical industry, in which case the crude phenols' end use is not as an energy product. Thus, the crude phenols should not be considered as an energy output of the system. CHAPTER 4 SUMMARY OF ENERGY ANALYSES Introduction This chapter summarizes the application of energy analysis to central receiver solar thermal power stations, systems supplying industrial process heat from solar radiation, crop producing systems and the production of alcohol from corn. Complete descriptions and documen- tation of the analyses summarized in this chapter are included in the appendices of this study. Summary of Energy Analysis of Central Receiver Solar Thermal Power Stations Description of System High efficiency collector subsystem (system 1) Energy analysis is applied to the system described in a design report prepared by Martin Marietta (1). The collector subsystem of the 150 MW(e) intermediate to peak load central receiver power station is comprised of fifteen collector modules. Each module consists of 1554 high efficiency heliostats focused on a single cavity-type receiver mounted on a 90m steel tower. The operational mode changes and the sun tracking motion of the heliostats are accomplished via an Open loop control system utilizing preprogramed microprocessors. Superheated steam is pro- duced in the fifteen receivers which is used directly to 91 92 drive a single turbogenerator. A three-hour thermal storage capacity (load factor of 0.5) is obtained through a combination of molten salt and oil storage. Waste heat from the electric plant is rejected using a wet cooling tower. Lower efficiency collector subsystem (system 2) Energy analysis is applied to the system described in a system evaluation prepared by the Mitre Corporation (2). The system is based primarily on ERDA contractor's generic design of a 100 MW(e) intermediate to peak load central receiver power station. The proposed collector subsystem is made up of three collector modules. Each module contains 7500 lower efficiency heliostats focused on a single cavity—type receiver mounted on a 198m concrete tower. The Operational mode changes and the sun tracking motion of the heliostats are accomplished via a closed loop control system utilizing sun-sensors. Superheated steam is produced in the three receivers which is used directly to drive a single turbogenerator. A three-hour thermal storage capacity (load factor of 0.5) is obtained through a steel ingot storage system. Forced air cooling towers are proposed for rejection of waste heat from the electric plant. State of System Outputs Central receiver power stations produce non- stored electricity fed into a utility grid as its primary 93 product. The system does not produce secondary products, nor waste products that require handling or disposal facilities not included in the power station itself. Energy Inputs and Outputs of System Due to the capital intensive nature of central receiver power stations, the energetics of such a system are strongly influenced by the lifetime of the system. The actual lifetimes of proposed central receiver power stations are not known. Thus, Table 4.1 and Table 4.2 list the energy inputs of systems 1 and 2, respectively, as a function of the system lifetime. The energy outputs of systems 1 and 2 are 2153 x 109 Btu per year and 1435 x 109 Btu per year, respectively. Table 4.1. Annual energy inputs required by system 1 (3) Transportation Embodied Energy Distance of 9 . Prototype (x 10 Btu primary/year) Energy Components a a a Input ‘ (miles) ‘ 20 yr 25yyr 30 yr Amortized Capital 100 1347 1093 924 500 1355 1100 929 1000 1366 1108 936 Raw Materials --- 69 55 46 Utilities --- --- --- --- Totals 100 1416 1148 970 500 1424 1155 975 1000 1435 1163 982 a - System lifetime 94 Table 4.2. Annual energy input required by system 2 (3) Transportation Embodied Energy Distance of 9 . Prototype (x 10 Btu primary/yr) Energy Components a a Input (miles) 20 yr 25 yra 30 yr Ammortized Capital 100 609 501 430 500 614 505 432 1000 619 509 436 Raw Materials --- --- —-- --- Utilities --- --- --- --- Totals 100 609 501 430 500 614 505 432 1000 619 509 436 a - System lifetime 95 Energy Parameters of System Table 4.3 lists the energy parameters of systems 1 and 2. Summary of Energy Analysis of Systems Supplying Industrial Process Heat from Solar Radiation Description of System Currently, solar industrial process heat systems are designed to be subsystems that are integrated into existing systems to operate in a fuel displacement mode. Thus, solar industrial process heat systems are utility supply systems, installed at the site of the existing system that will consume the process heat produced. Solar industrial process heat systems usually utilize low to moderate efficiency solar collectors such as flat plate collectors, evacuated tubular collectors, Winston con- centrating collectors, Fresnel lens concentrating col- lectors and parabolic trough concentrating collectors. If possible, the collector field is mounted on the roof of existing structures to minimize the required capital investment. Depending on the demand load for the process heat, thermal storage may or may not be required. Energy analysis is applied to the system designs of three solar industrial process heat systems described in system evaluations prepared by the Mitre Corporation (4). The energies embodied in the mentioned low to moderate efficiency solar collectors are estimated from 96 «Om.O III mmm mm.m mam mmO Om mmm.O III NON mm.m ONO OOm mm Hmv.O III mmm mm.m OHO OHO ON OOOH HOm.O III mmm mm.m MOOH mmv om Nmm.O III «mm vm.~ Omm mom mm ON0.0 III «mm wm.m HNO vHO ON oom OOm.O III vmm vm.m mOOH one Om mvm.O III Omm OO.~ vmm Hom mm vmv.o III Omm Om.m ONO OOO Om OOH m mmv.O III OHN OH.N HnHH mmm om mHm.O III mOH mO.H OOO mmHH mm vmo.o III omH Om.H mHh mmvH ON OOOH Hm¢.O III Hmm Hm.m OBHH mum om HHm.O III OOH OO.H mam mmHH mm ON0.0 III HmH Hm.H mmn ONVH ON oom Omv.O III mmm mm.m mmHH Ohm om mom.O III OOH mm.H mOOH OvHH mm ON0.0 III mmH mm.H nmh OHvH ON OOH H “Boom “Boom E cho CNEEW ngum Amummb HmmHHEO 63$ acme coHumNHHHuD_>ocmHonwm mmumcm 3pm OOH xv 5pm OOH xv mEHummfiH mucwcomeoo ImHfifimm mpfixmmm mmwxfim gwummw wfiflfiflofim 338 :6ng wazfi SEMEMMM mo 683mg H cofififlgQwfiafla I. .||l|ll| Amy pmthmcm mEmumhm mo mnmumEmHmm >mumcm .m.v mHnma 97 data describing the collectors found in the Mitre reports (2, 4) (see TablesB.9 and B.l for the embodied energies and energy outputs, respectively, of the mentioned solar collectors). Energy parameters are determined for the following solar industrial process heat systems: System I. 600-800C Hot Water - Textile Process Water The system is designed to supply 30% of the yearly hot water requirement at 600-800C from an available solar insolation of 550,000 Btu/ftZ/yr (South Carolina). About 5 ft2 of evacuated tubular collectors operating 2.5 x 10 at 50% efficiency over daylight hours are used to supply 180,000 gallons of water (at an average of 700C) per day. The system is estimated to collect 67850 x 106 Btu/yr with an estimated system lifetime of thirty years. System II. 800-1000C Hot Water - Can Washing The system is designed to supply 40% of the yearly hot water requirement at 800-1000C from an available solar insolation of 637,500 Btu/ftz/yr (southern California). About 150,000 ft2 of c0pper flat plate collectors operating at an average 40% efficiency are used to supply a maximum of 20,000 gallons/hr of hot water at an average temperature of 90°C. The system is expected to collect 38,250 x 106 Btu/yr with an estimated system lifetime of 35 years. System III. 1000—1500C Hot Air - Plastic Curing The system is designed to supply 90% of the hot air requirement at a constant temperature of 1490C. The system includes a recuperator heat exchanger to recover 98 exhaust air enthalpy and rock bed storage to provide thermal inertial for 48 hours at 150°C to 2000C. About 135,000 ft2 of Winston concentrating collectors are used with an available solar insolation of 650,000 Btu/ftZ/yr (California) Operating at an average daily efficiency of 50%. The system is expected to collect 29,565 x 106 Btu/yr with an estimated system lifetime of 20 years. State of System Outputs The primary products of systems I, II and III are process heat in the form of 600-800C hot water, BOO-lOOOC hot water and 100-1500C hot air, respectively. The primary product of each system is consumed at its production site. There are no secondary or waste pro— ducts reported for the systems analyzed. Energy Inputs and Outputs of System Table 4.4 and Table 4.5 list the annual energy inputs and outputs, respectively, of the systems analyzed. Energy Parameters of System Table 4.6 lists the energy parameters of the systems analyzed. 99 Table 4.4. Annual energy inputs of solar industrial process heat systems (5) Embodied Energy (x 109 Btu primary/yr) Input Ia IIa IIIa Amortized Capital b 50 miles 5.5 4.9 5.0 100 milesb 5.5 4.9 5.0 500 miles 5.5 5.0 5.1 Raw Materials -—- --- --- Utilities 0 5C 13.2 7.4 5.8 10C 26.4 14.9 11.5 20 52.9 29.8 23.0 a - System b - Transportation distance for collector delivery 0 - Per cent of total thermal output required as electrical input Table 4.5. Annual energy outputs of solar industrial process heat systems (5) Energy Output (x 109 Btu/yr) System I 67.850 II 38.250 III 29.565 100 OOH.O III OOH OO.H O.H 0.0m ON OOH.O III OOH O>.H H.mH m.OH OH OOH.O III Ohm vh.m m.mH 0.0H m HHH ONH.O III OHH OH.H O.m O.vm Om ONH.O III mOH mO.H m.OH m.OH OH ONH.O III HHm HH.m 0.0m m.NH m HH Hm0.0 III OHH OH.H m.O v.mm ON HO0.0 III mHm mH.m 0.0m O.Hm OH HO0.0 III mom mO.m N.Ov n.mH m H “Bump “88m E :80 EQEE Afixguq ufifi 3232 586mm usmewufloqmm coHumNHHHpD mocwHOwam mmumcm sum OOH xv sum OOH xv mm Umnflsvmm HmuHmmO mousomwm mmmoonm Omnmcm mpHmnsm usmuso HHmnm>O umz am am Hmeumna .dfioH Hflflaa monfiaohmfi Ame sum>flamt “OpomHHoo How monopme coHumuHommcmuu mHHE OOH m OCHEdmmm mEmuw>m ummn mmmooum HmHHpmSOCH “MHOm mo mumumEmumm hmnmcm .o.v OHQMB 101 Summary of Energy Analysis of Crop Producing Systems Description of System From an energy supply point of View, crOp pro- duction is the conversion of solar radiation into chemical energy stored in biomass. The process uses raw materials of seeds, fertilizers and chemicals, utilities of motor fuel and electricity and requires farm equipment (i.e., tractors, plows, discs, etc.) as capital. The feed to the process is freely available solar radiation. The capital, raw materials and utilities required for the production of specified yields of various crops are reported by Keener and Roller (6) and represent intensive cultural practices (i.e., maximum use of equipment, commercial fertilizers and chemicals for maximum crop yield) for crop production without the use of irrigation. The crop producing system includes operations performed in the field and the utility requirement for operation of the farm shop. The system does not include any general facili4 ties such as the farm house and farm shop. State of System Outputs The primary products of the crop producing systems analyzed are dried and chipped biomass ready for consumption as a solid fuel. The wet crops (as stored at the farmstead) are transported to the processing site where they are dried 102 and chipped. The biomass is assumed to be consumed at the processing site. There are no secondary or waste products reported for the crop producing systems. Energy Inputs and Outputs of System Table 4.7 and Table 4.8 list the energy inputs and outputs, respectively, of the crop producing systems analyzed. Energy Parameters of System Table 4.9 lists the energy parameters of the crOp producing systems analyzed. Summary of Energy Analysis of the Production of Alcohol from Corn Description of System Energy analysis is applied to the system design of a 50 MM gal per year (actual production) alcohol (199 proof ethanol) plant prepared by the Raphall Katzen Associates (8). The secondary products of the system are listed in Table 4.10. The system is designed to process 543,977 tons/yr of corn at a fifteen per cent moisture content. The corn is assumed to be delivered 500 miles from the farm to the alcohol plant via truck transportation. The process heat required by the system is supplied by 97899 tons/yr of #6 Illinois coal delivered via rail transportation. The delivery distance of the coal is 103 omwvm oom OOOO OOH NOOm OOvm mnnm OOO.VH mmvH om umwcz OONOmmH oom OmOHmm OOH Hmemm OmmmmH VOmOO Nom.mOH OOOHN om mch cmMHm ObnnHm OOm ommmOH OOH HOONMH OOOHm MOmmm www.mOH mmmv om mmmuo umHmmz OOOOO oom ommmH OOH OOOOH OOOO mmHv www.mm mOwH om mmcmx OOOmO oom OOHMH OOH mmbmH OOOO OOHO OOH.mN mOvH om CHOU OOOONH oom OOOvN OOH mOOHm omva mommH mn0.0m Nmmv om MMHme< amouu mo wmouo mo mmHuHHHpD mHMHumumz HmuHme AmeHEO wuHm mono mchmwoonm wum>HHoo 3mm OCHmmmooum ou mmouu AmHomo £u3oum any N mumEHum,Ozv mstcH OOHmcm wo wum>HHmo How mocmumHo COHumuHommcmua Any mEmumww OCHospona mono mo mvsmcH hmumcm .h.v OHQMB 104 Table 4.8. Energy outputs of crop producing systems (7) Crop Energy Output (MJ/hm2 Cycle) Alfalfa 645,500 Corn 348,800 Kenaf 331,500 Napier Grass 2,587,600 Slash Pine 4,933,400 Wheat 128,600 105 HH0.0 III hmm hm.m m.wn H.Om oom HH0.0 III mmv mm.v v.OO m.Om OOH HH0.0 III vow vo.v 0.00H n.>m om Hmong vO0.0 III Omm Om.m v.momm 0.0>ON oom vO0.0 III vow «O.v 0.0nmm v.mOOH OOH mch OO0.0 III mmm ON.m O.mOOm 0.0mO om smMHm NO0.0 III OOm OO.m O.vmnH O.NOO oom NO0.0 III hum nh.m H.OmHm m.mvv OOH NO0.0 III mmO mm.O m.OOHm 0.00m om mmmuw HmHmmz mO0.0 III OON OO.N 0.0HN O.HHH oom mO0.0 III mom OO.m O.mnm 0.0m OOH mO0.0 III Omo Om.O 0.0hm O.Hm om mmcmm «O0.0 III mom OO.m m.mm~ O.MHH oom vO0.0 III «mm v>.m 0.00N 0.00 OOH vO0.0 III OOO vv.O O.vOm m.vm Om cuou OO0.0 III OON OO.N 0.0mv H.OHN oom OO0.0 III «mm vm.m 0.0mm m.OHH OOH OO0.0 III ONO O~.O m.va O.vOH om MMHMMHd HmmHHEV menu Houomm uouomm w cho HmHomo suzoum we: AmHomo gpzopm me: mpHm poms coHumNHHHuO.mocmHonwm IOOuwgm I1 H Ochmooonm IOHqumm mousmem wmwooum .Hm Dz MOH xv .Hnw Dz MOH 5 8 macho HESS 2365 98%.. >3QO mo 528 umz mmuwcm Hmuoe MOM mocmumHo cOfififihQBBHGH any mEmpmwm OGHODOOHQ mouo mo muwumemumm mmumcm .O.v mHnma 106 Table 4.10. Secondary products of the alcohol plant Product Distillers Dark Grains Fusel Oil 40 Weight % Aqueous Ammonia Sulfide Solution Quantity 173,448 tons/yr 224,000 gal/yr 26,058 tons/yr 107 varied from 500 to 1500 miles. The system operates at a load factor of 0.90 (330 days per year) and has an expected lifetime of twenty years. State of System Outputs Quantities of the system products are given in the description of system. The secondary products are delivered 500 miles to their end-use site via truck transportation. The alcohol is delivered to its end-use site via truck transportation and the distance of delivery is varied from 500 to 1500 miles. Energy Inputs and Outputs of System Tables 4.11 and 4.12 list the energy inputs and outputs, respectively, of the alcohol plant. Energy Parameters of System The actual energy resource of the production of alcohol is solar radiation. However, the conversion of the crop to the liquid fuel (alcohol) consumes a great deal of energy as process heat. It is proposed that the consumption of crude oil in the production of gasoline be displaced by the production of alcohol from corn, consuming coal for the supply of the required process heat. The obvious alternative to alcohol production is the production of liquid fuels directly from coal. The overall process efficiencies of alcohol production and coal liquefaction will indicate which process produces liquid fuels more efficiently 108 Table 4.11. Energy inputs of the alcohol plant (9) Input Embodied Energy (x 109 Btqurimary/yr) Capital (amortized over plant life) 92 Raw Materials 1910 Utilities 920 Coal - energy content 2085 energy subsidy (non— delivered) 18 Delivery of Coal - 500 miles: 73 1000 milesa 147 1500 miles 220 Delivery of Alcohol - a 500 milesa 576 1000 milesa 1153 1500 miles 1729 Delivery of Secondary Products - 500 milesa 701 a - Delivery distance Table 4.12. Energy outputs of the alcohol plant (9) Energy Content Energy 9 Product (x 10 Btu/yr) Alcohol 4203 Distillers Dark Grain 2834 Fusel Oil 34 109 (i.e., with the least energy embodied in the fuels produced). Furthermore, the resource utilization factor based on the assumption that coal is the energy resource of the alcohol producing system is 0.29 (9) compared to a resource utilization factor of 1.49 (10) for coal liquefaction. Table 4.13 lists the energy parameters of the production of alcohol based on the resource of solar radiation. 110 MH0.0 III NO N0.0 vOOI much oomH MH0.0 III MO O0.0 HmmI NOOO OOOH MH0.0 III «O O0.0 hva ONmb oom OOOH MH0.0 III OOH OO.H ON I OOOO oomH MH0.0 III HOH HO.H mv ONOO OOOH mH0.0 III NOH NO.H OHH NmOO oom OOOH MH0.0 III OOH OO.H Ovm NNmO oomH MH0.0 III OHH OH.H NNO Ovvo OOOH MH0.0 III HHH HH.H OOO mhmo oom com uoaomm nouomm va CHmO Hp>\mum5Hnm QNVNHMEHHQ Hmoo Hosoudm acmemanqom coprNHHHuD mocwHonmm woumcm OOH xv Dam OOH xv AmmHHEV mmocmumwo HmuHmmu wousomom wwwooum mmumcm OOH coHumuuommCMHB .. m o 6.62 .385. Hfifiau 'Il ‘Ii ...I'IIII l HOV COHOMHUMH umHOm mo monsowwu amumcm cm :0 comma coHvospoum Hocoon mo mnmumfimumm wmnmcm .MH.v OHQMB CHAPTER 5 BACKGROUND AND HISTORY OF ENERGY ANALYSIS APPLICATIONS Introduction Interest in and the recognition of the need for the science of energy analysis dates back to the early 1900's. However, the deveIOpment of the science was not initiated until the early 1970's as a result of the "Federal Non- Nuclear Energy Research and Development Act of 1974", public law 93-577 (1). This act of Congress was established to instigate a research and development program designed to make available to American consumers the large domestic energy reserves of the United States. Parts four and five of Section five-a of the act state the following: Sec.5(a) (4) Heavy emphasis shall be given to those technologies which utilize renewable or essentially inex- haustible energy sources. Sec.5(a) (5) The potential for production of net energy by the proposed technology at the state of commercial appli- cation shall be analyzed and considered in evaluating pro- posals. Thus, application of energy analysis is indeed an undeveloped science. However, a significant number of applications do appear in the literature. Since energy 111 112 analysis is not standardized as yet, applications vary greatly in methodology and content from complete, well- documented work to non-documented analyses. Thus, the need exists to evaluate all analyses before accepting their results. The literature has been surveyed for energy analy- sis applications. The applications found are evaluated and summarized in this section. Unlike the methodology or theory of energy analysis, which is a specificauea of discipline, the application of energy analysis is a tool for system evaluation that may be applied to systems of many different disciplines. Due to the "diffuse" nature of published and unpublished energy analysis applications, this survey may be somewhat incomplete. The summaries of the literature analyses are reported as either individual analyses (i.e., the analysis of a single energy supply system) or comprehensive analyses. The individual analyses are categorized according to the following energy resources: 1. Nuclear fuels 2. Solar energy i. Collection of solar energy as heat a) Solar thermal electric systems b) Supply of domestic hot water and space heating ii. Crop production follows: 113 iii. Production of alcohol iv. Direct conversion of solar energy to electricity a) Wind energy b) Ocean thermal energy c) Photovoltaics The comprehensive analyses summarized are as 1. Energy supply systems based on fossil fuels (production of fuel and electricity from crude oil, natural gas, coal and oil shale) Ocean thermal energy conversion, wind energy, in-situ oil shale processing, fluidized bed and conventional coal combustion and municipal wastes disposal Nine electricity generating systems 114 Summaries of Individual Analyses Nuclear Fuels Comments The question of whether nuclear power plants are net energy producers or consumers has spurred the applica- tion of energy analysis by several investigators (5, 7, 8, 23). The results of the various analyses show that nuclear power stations are indeed net energy producers. Apparently, the highly energy intensive fuel processing operations and power plant are offset by the high energy intensity of the fuel, uranium. The high energy subsidy intensity per volume throughput of fuel renders the energy parameters of the system sensitive to the type of uranium ore (i.e., natural uranium concentration), parameters of the U235 enrichment processes (such as the tails assays) and the recycle of "active" material left in spent fuel. The crucial result of these analyses is not that nuclear power is a net energy producer but, under certain design conditions, that electricity from nuclear power can compete energetically with electricity from fossil fuels. The reader is referred to an article by G. T. Mays (31) for a contrasting and comparison of analyses by various authors. Description of systems Many configurations of the conventional (i.e., non- breeder) nuclear power plant exist depending on the 115 variations of the reactor design and the nuclear fuel cycle. Energy analyses of light water reactors including pressure water reactors (PWR) and boiling water reactors (BWR), heavy water reactors (HWR) and high temperature gas cooled reactors (HTGR) with various fuel cycles are reported in the literature. P. F. Chapman (5) reports an energy analysis of a 1000 MW(e) PWR, HWR and HTGR. The reactor design details are contained in capital investment cost breakdowns by the CEGB (6). Parameters of the fuel cycle of each reactor are listed in Table 5.1. The fuel cycles analyzed by P. F. Chapman (5) do not recycle spent fuel. Table 5.1. Fuel cycle parameters of nuclear power plant designs analyzed by P. F. Chapman (5) Natural Uranium Fuel Required for Inventory for Tails Reactor Initial Core Initial Core Enrichment Assays Design (tonnes) (tonnes) (%) (%) HWR 182 182 natural --- HTGR 308 22.7 6.5 0.25 PWR 862 130 3.3 0.25 The power plants have an expected lifetime of 25 years and a capacity factor of 0.62. The distribution of the electricity is reported to consume 7.5% of the system's out- put. 3.75% of the system's output is fedback to operate the plant. Chapman (5) reports the energy required for 116 refueling to be a feedback of the system's output. The PWR, HWR and the HTGR require 49.2, 3.2 and 42.6 MW(e), respectively, for refueling over the lifetime of the plant. Rotty, Perry and Reister (7) report an energy analysis of a 1000 MW(e) PWR, BWR, HWR and HTGR for various fuel cycles. The reactor design details are obtained from Volumes 1 and 2 of "The Energy Supply Planning Model" pre- pared by the Bechtel Corporation (32). The power plants are estimated to have a lifetime of 30 years and a capacity factor of 0.75. Rotty, Perry and Reister (7) report the energy requirements for fuel cycles with tails assays of 0.20%, 0.25% and 0.30%, with or without recycle of uranium and plutonium from spent fuel rods and with either conven- tional ores or Chattanooga shales* as the uranium source. The fuel cycle requirements are reported as annual system inputs rather than as an initial core input and a feedback of the system's output for refueling as reported by Chapman (5). Rombough and Koen (8) report an energy analysis of a 1000 MW(e) PWR and BWR. Uranium and plutonium are recovered from the spent fuel rods and 0.2% tails assays are specified for uranium enrichment. The power plant design details are contained in Volumes I (PWR) and II (BWR) of "1000 MW(e) Central Station Power Plants Investment Cost Study" (9). A *Chattanooga shale is a low grade uranium ore containing approximately 0.006% natural 0238. Conventional ores have an average 0238 concentration of 0.176%. Unless noted otherwise, fuel cycles are based on conventional ores. 117 lifetime of 30 years and a 0.8 capacity factor are specified for the power plants. Moraw, Schneeberger and Szeless (23) report an energy analysis of a 1000 MW(e) PWR with a 0.75 capacity factor and a plant lifetime of 30 years. The fuel cycle includes the recycle of spent fuel rods and assumes a 0.3 per cent tails assays for uranium enrichment. Power plant design details are found in reference (9). Moraw, et al., (23) update the design details of reference (9) to account for technical changes. Description of analyses The energy analyses of the various authors are similar in that some form of input-output analysis is applied to determine the energy embodied in the power plant itself and process analysis is extended both backwards and forwards along the horizontal feed trajectory (i.e., the fuel cycle) to determine the energy embodied in the delivered fuel rods and the energy required to either recycle or dispose of the spent fuel. The analysis by Rotty, et al., (7) is by far the most complete and best documented effort. Thus, the results from Rotty's analysis (7) will be used for comparison of nuclear to other energy supply technologies. All analyses reported define the unit energy equivalence as either a unit of delivered electrical energy or a unit of thermal energy and separate accounts are kept for each energy form {exclud- ing Rombough and Koen (8)}. 118 Rotty (7) and Moraw (23) utilize the energy inten- sity coefficients for the year 1967 (10) to determine the energy embodied in the power plant. By using the energy intensity coefficients which correspond to the various energy producing sectors (i.e., coal, crude oil and natural gas, petroleum products, electrical utilities and gas utilities), separate accounts are kept for thermal and electrical energy requirements (i.e., coal and crude oil and natural gas coefficients are summed to give a thermal energy coefficient). However, this use of the energy inten- sity coefficients leads to a double counting of embodied energy since the majority of electricity is produced from coal, crude oil and natural gas. Rotty (7) corrects for the double counting by subtracting the coal and crude oil and natural gas consumed for production of the required electric- ity from the total coal and crude oil and natural gas requirement. The energy coefficients for electric utilities list the Btu's of coal and crude oil and natural gas con- sumed per Btu of electricity produced (10). The results of Rotty's analysis (7) report the energy requirements as the total electric energy requirement and the corrected thermal energy requirement. Moraw (23) corrects for the double counting in the same manner as followed in the definition of a unit of primary energy (i.e., the electrical energy input is reduced to the portion produced from hydroelectric and nuclear power). Moraw (23) presents his results in the uncorrected form allowing the calculation of energy 119 requirements as units of primary energy. Rotty (7) estimates the energy required to erect the power plant and install the equipment using the disaggregation of energy intensity coef- ficients, whereas Moraw (23) assumes these energy require- ments to be included in the capital investment costs. Rombough and Koen (8) use the single sector input- output approach to determine the energy embodied in the power plant from the total required capital investment. Thus, Rombough (8) reports the energy embodied in the power plant in terms of units of primary energy. However, only the electrical energy requirements are reported for the fuel cycle energy requirements. The methodology used by Chapman (5) to determine the energies embodied in the power plants is not documented. The fuel cycles of nuclear power plants are com- prised of the following unit Operations: Mining of uranium ore, milling of uranium ore producing U308 (yellow cake), Iconversion of U308 to UF6, enrichment of uranium, fuel rod :fabrication, spent fuel reprocessing (optional), and waste (iisposal. Also, there are transportation requirements for Cielivery of material from one unit operation to the next and, Llltimately, to the power plant. The analysis by Rotty, Gat.a1., (7) includes a thorough and complete extension of Elrocess analysis to determine the energy requirements of the 1fuel cycle unit operations. Moraw (23) uses Rotty's (7) Einalysis for fuel cycle energy requirements. Chapman (5) E12nd Rombough (8) generate fuel cycle energy requirements 120 independently. The largest discrepancy in energy require- ments for fuel cycles reported by the various authors deals with the enrichment energy requirement. Table 5.2 compares the various enrichment energy requirements reported. Table 5.2. Enrichment energy requirements reported by the various authors Enrichment Energy Requirement Thermal Electric Author (x 106 Btu/SWU) (MWh/SWU) Rotty (7) 0.798 2.8235 Chapman (5) 0.097 2.42 Rombough (8) ---a 2.582 a-value not reported Energy inputs are required for operation of the power plant and distribution of the produced electricity. Chapman (5) assumes a 7.5% loss of the produced electricity for (iistribution and a 3.75% feedback for internal consumption. IRotty (7) includes the energy required for plant operation iJn the energy embodied in the plant, and Moraw (23) and 1%ombough (8) neglect the energy required for plant opera- tlion. Rotty (7), Moraw (23) and Rombough (8) neglect the energy required for distribution of the electricity. §§jtate of systems outputs The outputs of the systems analyzed by Chapman (5) Eire distributed electricity while the outputs of the systems 121 analyzed by Rotty (7), Moraw (23) and Rombough (8)8me non- distributed electricity as it is produced at the power plant. The systems have no secondary products and facili- ties for the disposal of waste products are included in the fuel cycles. Energy inputs and outpuusof systems Tables 5.3 and 5.4 list the lifetime energy inputs of nuclear power plants as reported by Chapman (5) and Rombough (8), respectively. The analysis by Rotty (7) allows the evaluation of 52 reactor configurations. The lifetime energy inputs of 6 reactor configurations are presented in Table 5.5 and the design parameters of the 6 reactor configurations are listed in Table 5.6. Recyle of uranium and plutonium from the spent fuel rods, 0.3% tails assays from conventional ores represent the base case fuel cycle. The lifetime energy inputs of the PWR, BWR, HWR and HTGR are presented for the base case fuel cycle (note that the HWR requires no enrichment of uranium). The life- time energy inputs for the PWR with fuel cycle variations (of 0.2% tails assays and no recycle of uranium or plutonium are presented for comparison purposes. The fuel cycle lifetime energy requirements listed for system 1 (i.e., IPWR, 0.3% tails assays, recycle) of Table 5.5 and a capital 6 Btu thermal lifetime energy requirement of 13,652,000 x 10 and 300,000 MWh(e) are the energy inputs reported for the system analyzed by Moraw (23). Table 5.3 122 . Lifetime energy inputs to systems analyzed by P. F. Chapman (5) __ Lifetime Energy Requirement (Thermal - 106 Btu, Unit Energya Electric - MWh) Operation Form PWR HWR HTGR Mining * th 813,771 171,670 291,174 agiling e 23,055 4,889 8,333 Enrichment* th 191,587 -—- 85,361 e 1,398,294 --- 619,427 Fuel Fabrication* th 14,227 19,917 2,845 e 6,111 8,611 1,111 Capital th 10,157,910 11,505,659 10,909,083 e 270,270 306,103 290,270 Heavy* Water th -—- 14,340,579 --- e --- 454,987 --- Refueling th --- --- --- e 10,774,800 700,800 9,329,400 Heavy Water th --- --- --- e --- 1,149,750 --- *initial core energy requirement a - th thermal energy electrical energy Table 5.4. 123 Lifetime energy inputs to systems analyzed by Rombough (8) Lifetime Energy Requirement Unit Energya (Electric - MWh6 Operation Form (Primary - x 10 Btu primary) PWR BWR Mining e 7,380 7,380 Milling e 289,500 289,500 Enrichment e 9,300,000 9,000,000 Fabrication e 71,400 71,400 Reprocessing e 14,010 14,010 Capital p 15,000,000 15,000,000 a - e 5 electrical energy p E primary energy 124 mucmwmummn mOuocm mHLB mmumcm HMOanome u m .mmhwcm Hmfiumnu an I n .mOmHoum pom Hmsw ucmmm How pmHHquH mmumcm .wHomomu unocuHB mmHomo HmSH How pmuHDOmH no: mH Ochmmooummm I * .mEmumOm msoHum> can mo mumumemumm map mumHH O.m wHQMB I m mme.m OMH.~ mew OHm.m on.m mmH.~ m omm.smm oom.~mm oom.omH ome.mme oem.eem omm.mom cu coHucuuommccus OHo.m 0Ho.m OHo.m HoH.m oao.m OHo.m m oom.mmH oom.mmH oo~.mmH oom.mmH oom.mmH oo~.mmH cu mmcuoum mama: ocm.mH Ioom.mH ooe.mH oem.nm omm.mH emm.mH m ooc.mmm Ioem.mmm ooe.mem OHm.sc omo.mm oom.mm~ cu mchmmooummm oom.Hce oom.Hoe eoo.mme ooo.oaH.H oo~.cme oom.Hce m ooo.oeH.mH ooo.oeH.mH ooo.omm.mH ooo.oso.em ooo.oeo.mH ooo.oeH.mH cu ucmHm umzom ooe.se~ oom.mo~ oom.Hs ooe.emc oom.sHm oom.mcm m coHumoHunmm ooo.moH.~ ooo.~se.~ ooo.mmH.H oom.mHm.m ooc.mHm.~ ooo.~ee.~ cu Hmsm ooo.mmm.m ooo.mom.n ooo.emo.e III oom.emo.m ooo.coo.o m ooo.~He.N coo.HmH.m ooo.moo.m III oom.esm ooo.mmc.H cu ucmscoflucm oce.mm omc.me oom.He III 00H.Hm oaH.mm m ooo.csm.s ooo.mmo.¢ ooo.~mm.m III eom.mmsre ooo.mmm.e cu conum>coo oom.mNH omo.cm ome.me eos.He omm.eh one.om m ooo.mmm.m ooo.omm.H ooo.mme.H oom.Hmm oom.smm.H ooo.mHm.H cu mcwHHHz OOH.OHH omm.cm oom.em onm.om oom.nm omm.os w ooo.coo.m ooo.mmm.H ooo.eme.H oom.mmo oom.Hmm.H ooo.emm.H cu mchHz mo cm me am mN mH Euom COHumummo 1:22 I Hmofluuomam .spm OOH Hegemcec scumcm uHcD udmcH hmuwcm mEHHOMHH HOV .Hm no .Opuom On pmumecm mpcde umzom ummHosc Amvzz OOOH on musmcH OOHmcm mEHHOMHH .m.m magma 125 Table 5.6. Parameters of nuclear power plant systems analyzed by Rotty, et a1. (7) Tails Recycle of Reactor System Assays U and Pu Type 1 0.3 yes PWR 2 0.3 yes BWR 3 --- yes HWR 4 0.3 yes HTGR 5 0.2 yes PWR 6 0.3 no PWR 126 The energy content of the energy resource (i.e., uranium) required by nuclear power plant systems is a useful quantity for comparing nuclear power to other energy supply systems. However, only Rotty (7) reports the total amount of natural uranium required over the lifetime of the system. Natural uranium has a U235 content of 0.71 (7) weight per cent and U235 has an enthalpy of 75.69 x 106 Btu/kg (11). Table 5.7 lists the amountsand energy contentsof the natural uranium required by the systems analyzed by Rotty (7). Table 5.8 lists the lifetime energy outputs of the systems analyzed by the various authors. Table 5.7. Lifetime quantity and energy content of natural uranium required by the systems analyzed by Rotty (7) Lifetime Uranium Requirement System. a Quantity EnergyGContent Description (MT) (x 10 Btu) l 3643 1,963,180,000 2 3500 1,886,115,000 3 2829 1,524,520,000 4 1888 1,017,424,000 5 2990 1,611,281,000 6 5682 3,061,973,000 Et—refers to system description listed in Table 5.6 x 127 Table 5.8. Lifetime energy outputs of nuclear power plant analyzed Lifetime Energy Output of Systems Analyzed by Specified Author Author (MWh) P. F. Chapman (5) 115,029,750 Rotty (7) 197,100,000 Moraw (23) 197,100,000 Rombough (8) 210,240,000 128 Energy parameters of systems From the energy inputs and outputs reported by the various authors, it is possible to generate energy parameters for each system analyzed. However, this requires the com- bination of the electrical and thermal energy inputs to form a single energy requirement. All electrical requirements {excluding the capital electrical requirement reported by Moraw (23)} are multiplied by the energy intensity coef— ficient, 13,293,976 Btu primary per MWh (10), to obtain the primary energy embodied in the electricity. The electrical requirement is then added to the thermal energy requirement to obtain a single energy input very similar to the defini- tion of primary energy. The thermal and electrical capital energy requirements reported by Moraw (23) are combined according to the definition of primary energy (i.e., thermal energy + 0.6165 electrical energy). The capital energy requirement reported by Rombough (8) is already in the form of primary energy. Table 5.9 lists the energy parameters of all systems analyzed. Solar Energy Collection of solar radiation as heat Comments Collection of solar energy as heat for small scale supply of domestic hot water or space heating, for inter- mediate scale supply of industrial process heat and for large scale supply of steam to an electricity generating plant O.m mHQMB CH UmumHH mcoHumHuommp Emumwm cu mumwmh I m 129 OM0.0 mm.v m0.0N OO.v mH0.0m OOVOH MO OM0.0 OO.N «.mm Nh.v OOO.mm NONVH mm nmo.O ON.N 0.0v OO.m OOO.mm NONmH we OO0.0 Hm.H O.NO N0.0 mHv.OO NmOO um cmo.o om.~ H.4m mm.s ses.mm mmmm cm mmo.o mm.m N.~m He.m mmm.em NeemH 8H suuom omo.o es.m m.em em.m HHm.oc eeeHH mam smuo: HN0.0 III III OH.m th.nm MBOmH mzm HN0.0 III II mm.e mmm.sm msmea mam cmsonaom Om0.0 III II OO.N nom.vN mman moem oeo.o III II ee.c ceH.mm emoc mam teenage mm0.0 III III NN.N Hmm.HN OOOOH m3m .m .m uouowm uouomm Hwy ch0 Asum Asum COHpmeommo nonunm ucmE :oHumN mocmHonmm hmymcm OHOH xv OHOH xv Ewumwm Iwuasqwm IHHHuD mmmooum . . . >Oumcm thmQDm HMUHQMO mouzommm HHmum>O umz >Oumcm Hmuoe pwmemcm mEmummm HGMHQ Hmzom ummHonc mo muwumEMHmm mmumcm .O.m mHnma 130 represent the majority of the current feasible solar appli- cation technologies (wind energy and the production of bio- mass comprises the remainder of the feasible technologies). In this case the term "feasible" is meant to represent a combination of economic and technological conditions that allow solar energy technologies to compete with fossil fuel based energy supply. In other words, the mentioned technolo- gies represent systems which could feasibly penetrate the fossil fuel market under certain economic conditions, such as tax incentives, etc. A good deal of federal research funding has been provided for the development of the mentioned solar technologies with an emphasis on engineering technically sound systems which are economically competitive with fossil fuels. President Carter has set a goal for the supply of 2 quads of energy per year from solar energy systems by the year 2000 (33). With a major research program directed towards solar energy, very little effort is being extended to determine beyond doubt whether solar energy technologies can be net energy producers. The analyses of solar thermal technologies that do appear in the literature are incomplete in determining the energy subsidies of the systems (2, 4, 23, 25, 26) and yet the results of these analyses indicate that solar thermal applications are marginal energy supply systems. Not only can energy analysis indicate whether the solar energy supply system is a net energy producer or consumer, energy analysis can also identify the portions 131 of the system to which design research should be directed in order to improve the net energy producing capability of the system. Furthermore, energy analysis can determine the optimal role of solar energy supply systems in a national energy policy through the use of a dynamic energy supply and demand model. The energy producing capabilities of the highly capital energy intensive solar energy supply systems are extremely sensitive to system designs. Thus, any design research of solar energy supply systems should be closely monitored with energy analysis, as well as economic analysis. Without the information offered through energy analysis, it is difficult to develop an energy policy which optimally exploits the solar energy technologies available to the United States. Solar thermal electric systems Description of systems. The analysis reported by Baron (2) is based on the data obtained from an ERDA (3) environmental assessment of a 100 MW(e) solar thermal electric plant with 3 hours storage. The plant is estimated 6 ft2 of land. A six inch concrete matt to require 26 x 10 foundation for the collector field is added to the design to minimize dust formation on the collectors and to allow water to drain from the field. The material requirements reported by ERDA are increased by 50 per cent to account for losses, final design and replacements. The plant is estima- ted to operate at a capacity factor of 29.7% in the South- western United States for a lifetime of 30 years. 132 Moraw, Schneeberger and Szeless (23) report an energy analysis applied to the design of a 1000 MW(e) solar thermal electric power station published by the Aerospace Corporation (24). The plant is designed for base load operation (i.e., 12-hour storage) with a capacity factor of 79% over a lifetime of 30 years. The collector subsystem is made up of three modules, each with 15,400 heliostats focused on a receiver mounted on a 260m tower. The 6 2 collector field requires 42 x 10 ft of land to accomodate 6 ft2 of collector surface area. 16 x 10 Meyers and Hildebrant report an energy analysis of the solar radiation collection subsystem of a 10 MW(e) solar thermal electric power station (25). The collector subsystem is comprised of 2,200 heliostats, a receiver and tower including the risers and downcomers. The heliostat is a McDonnel-Douglas concept with an octagonal reflective surface using eight glass segments. The sun tracking motion is controlled with a sun-sensor pole and is included in the material requirements of the collector subsystem. Description of analyses. The major contributor to the total energy subsidy of systems producing electricity from solar radiation is the solar collector subsystem (i.e., including both collectors and receivers). Energy analyses of solar collectors and receivers commonly determine the materials required for fabrication and the energy embodied in the materials while neglecting direct energy usage and energy embodied in capital facilities required for collector 133 and receiver manufacture as well as the energy required to distribute the manufactured product. The analyses reported by Baron (2), Moraw (23), and Meyers (25) first determine the material requirements of the power station (or col- lector subsystem as reported by Meyers). Baron (2) and Meyers (25) determine the energy embodied in the materials using process analysis and Moraw (23) uses input-output analysis. Baron (2) includes energy requirements for construc- tion labor and machinery for construction of the power station. Moraw (23) accounts for the energy required for construction of the power station in the total cost for buildings that represents a contract fee paid to a sub- contractor. However, neither analysis includes energy requirements for the transportation or installation of equipment and components. The unit of the energy equivalence utilized in the analyses by Baron (2) and Meyers (25) is defined as a Btu of thermal energy. Baron (2) assumes 3.34 Btu's of thermal energy are embodied in a Btu of electricity. Meyers (25) assumes the amount of thermal energy consumed to produce the electricity to be embodied in the electricity (i.e., Meyers uses a thermal efficiency). Moraw (23) keeps separate accounts for thermal and electrical energy subsidies that are combined according to the definition of primary energy. 134 State of systems outputs. The primary products of the systems analyzed by Baron (2) and Moraw (23) are non- distributed electricity at the busbar. The system analyzed by Meyers (25) has no product (i.e., the purpose of the analysis is to determine the energy embodied in the col- lector subsystem of the power station). Baron (2) and Moraw (23) do not report secondary or waste products. Energy inputs and outputs of systems. Table 5.10 lists the lifetime energy inputs and Table 5.11 lists the lifetime energy outputs of the systems analyzed. Table 5.10. Lifetime energy inputs of solar thermal electric systems Energy Subsidy Baron (2) Moraw (23) Meyers (25) Input (x 1011 Btu (x 1011 Btu (x 1011 Btu Thermal) Primary) Thermal) Capital 120 707 1.58 Raw Materials --- -—— ___ Utilities --- --- --- Table 5.11. Lifetime energy outputs of solar thermal electric systems Lifetime Energy Output Author (x 1011 Btu) Baron (2) 266 Moraw (23) 7086 135 Energy parameters of systems. Table 5.12 lists the energy parameters of the systems analyzed. Supply of domestic hot water and space heating Description of systems. Baron (2) reports an energy analysis of a solar heating system designed to supply 50 per cent of the hot water requirement of a two-story single family reference house (four occupants) with 1800 sq. ft. of roof area. The General Electric Company has surveyed several areas of the United States for the annual energy requirements for space heating and hot water supply of the reference house and for the annual collectable solar energy (27). An alumi- num and copper solar collector with an acrylic cover (esti- mated lifetime of 20 years) is utilized in the system. The collector is assumed to convert diffuse solar radiation into heat at an efficiency of 30 per cent. The system includes a 650 gallon steel storage tank using ethylene glycol as the working fluid, a c0pper heat exchanger, copper plumbing and required pumps. The system is assumed to require 6.5% of the heating load as electricity for system operation. H. J. Wagner (26) reports the energy analysis of several configurations of solar space heating and hot water supply systems for a single family reference house (four occupants) with 140 m2 of housing space in the Federal Republic of Germany. Wagner (26) compares the primary energies consumed by the reference house for space and water heating supplied from central oil heating alone (at an efficiency of 60%) 136 OOH.O III NOOH N0.0H OOMO hon 3wuoz Hmv.O III NNN NN.N OOH ONH coumm Houomm Houomm Hwy ch0 Adam OH xv Asum OH xv H0£u5¢ acme coHumNHHHuD wocmHonmm OOumcm wwumcm mHmmnsm IwHHqum mouDOmmm mwoooum umz mmumcm Hmuueco Hchm>o Hmuoe mEmmem 0HupomHm Hmauwcu umHOm mo mumumfimumm wmuwcm .NH.m OHQMB 137 and from a combination of central oil heating, electrical heating and solar heating. The reference house has an estimated annual heat load of 85.3 x 106 Btu thermal for space heating and 13.7 x 106 Btu thermal for hot water supply. For energy supply from oil alone, 165.0 x 106 Btu of light fuel oil is required. Wagner (26) assumes 1.1111 Btu of primary energy to be embodied in a Btu of the fuel oil. Thus, the reference house has a total fuel energy requirement of 183.3 x 106 Btu primary for space heating and hot water supply from central oil heating alone. Wagner (26) considers the energy requirements for installation of the three solar energy supply systems listed in Table 5.13. Table 5.13. Characteristics of solar energy supply systems analyzed by Wagner (26) Portion of Energy Requirementa Hot ggiieCtor Supplied Water Space 2 System (%) Supply Heating Storage (M ) II 42 Yes yes yes 35 III 63 yes yes yes 65 a - System I supplies 58% of annual hot water requirement only. The solar heat load share is determined from Optimization calculations. 138 The remainder of the energy requirement not supplied by solar energy is supplied by electricity and oil. Elec- tricity supplies the hot water energy requirement during the summer months (i.e., 25 per cent of the total hot water energy requirement) at a boiler efficiency of 95 per cent. The remaining energy requirement is supplied by oil at an increased boiler efficiency of 65 per cent (due to not running during the summer months). Wagner (26) neglects the additional electricity requirement for Operation of the solar energy supply systems. Description of analyses. The shortcomings of the literature energy analyses applied to solar thermal electric systems, which are described in the description of analyses of solar thermal electric systems, exist in the literature applications of energy analysis to solar domestic energy supply systems (i.e., the incomplete assessment of energy embodied in solar collectors and receivers). Baron (2) uses process analysis to determine the energy embodied in the solar hot water supply systems and Wagner (26) does not describe the methodology used. Neither author documents the analysis. Baron (2) defines the unit of energy equiv- alence as a Btu of thermal energy and assumes 3.34 Btu of thermal energy to be embodied in a Btu of electrical energy. Wagner (26) defines the unit of energy equivalance as a Btu of primary energy and assumes 3.33 Btu of primary energy to be embodied in a Btu of electrical energy. 139 State of systems outputs. The only product of the system analyzed by Baron (2) is stored thermal energy. Wagner (26) reports products of stored and non-stored thermal energy, or of energy savings. A11 systems analyzed are installed at the end-use site of the product. Energy inputs and outputs of systems. Tables 5.14 and 5.15 list the lifetime energy inputs and outputs, respectively, of the systems analyzed by Baron (2) as a function of location. Tables 5.16 and 5.17 list the annual energy inputs and outputs, respectively, of the systems analyzed by Wagner (26). Table 5.14. Lifetime energy inputs to the systems analyzed by Baron (2) Embodied Energy (x 106 Btu Thermal) Input Wash., D.C.a Bostona Phoenixa Charlestona Capital 493 916 314 514 Raw Materials --- --- --- --- Utilities 300 600 186 315 a-location of system 140 Table 5.15. Lifetime energy outputs of systems analyzed by Baron (2) System Lifetime Energy Output Location (x 106 Btu Thermal) Washington, D.C. 1380 Boston 1800 Phoenix 1160 Charleston 1260 Table 5.16. Annual energy inputs to systems analyzed by Wagner (26) Embodied Energy (x 103 Btu Primary/Yr) Input Ia IIa IIIa Amortized Capital 1,758 6,587 11,399 Raw Materials --- ——— --- Utilities --- --- --- a - Description of system is listed in Table 5.13. 141 Table 5.17. Annual energy outputs and energy savings of systems analyzed by Wagner (26) Annual Energy Annual Output Energy b (x 103 Btu) SaVIggs System ( Yr ) (x 10 Btu Primary/Yr) I 7,918a 26,713a II 41,570 81,598 III 62,356 118,418 a-Based on 85 per cent supply of hot water during summer months and 49 per cent supply during winter months (i.e., 58 per cent yearly supply). b-Description of system is listed in Table 5.13. Energy parameters of systems. Table 5.18 lists the energy parameters of solar domestic energy supply systems analyzed. Crop production (production of stored chemical energy viayphotosynthesis) Comments The growing dependence of the agricultural industry on fossil fuels (mainly crude oil and natural gas) has resulted in enormous improvements in crop yields and farming efficiency (20). However, the almost total dependence of western farming practices on fossil fuels has rendered the most essential American industry at the mercy of an increas- ingly unstable petroleum products market. Application of 142 .mummw ON On Op mEmumOm mHmmsm OOHOCO OHummEOU umHom may mo OEHDOMHH .OH.m OHQMB cH OmumHH mH Emummm may mo coHumHuomOQ may mwumEHumm HOCOOB .mOcH>mm mmuwcm wumEHum :0 pmmmn mumuOEmHmm Emumwm ou mummmn n .Empmwm mo usmuso HmEumcu co Ommmn mumumEmumm mOuch on mummwu m I o OO0.0 III OOOH Om.OH OOHN ONN OQIHHH OOH.O III BOO Ov.m OHOH ONN omIHHH HO0.0 III OONH Om.NH OOOH NmH OQIHH OOH.O III OOO Om.O OOO NOH OMIHH OO0.0 III ONOH ON.OH OOO mm UQIH Hmm.o III Nme mm.e mmH mm OMIH “ONO umcmcz OO0.0 III NmH NO.H Hmv ONO coummHHmcu HON.O III NON Nm.N OOO OOO chmocm OO0.0 III OHH OH.H «ON OHOH coumom hmm.O III OOH OO.H OOO mOh .0.0 ..Smmz HNV coumm uoumwm mmwomm mommawwv ch0 Adam OOH xH Asum OOH xv coHuQHuomMQ HOSHU¢ Imuawqmm Iawwum mwmquw OOHocm mOnmcm OpHmnsm Emum m Hmemmu moumowmm HHmum>o umz OMMMMW OHumOEOO HOHOO mo mumumfimumm mmuwcm meummm memsm mmumcm .OH.m OHQMB 143 energy analysis to crop production illustrates the increas- ing dependence of the industry on fossil fuels and the large amounts of energy embodied in the crops. Description of systems Keener and Roller report the energy requirements, expected average yields and energy outputs for the production of corn, alfalfa, napier grass, kenaf, slash pine and wheat (21). The data presented by Keener and Roller (21) serve as the basis for the energy analysis of crop produc- tion in this report with modifications to account for trans- portation and crop processing energy requirements. The results of the analyses do not differ significantly and a summary of Keener and Roller's analysis (21) is not neces- sary. Pimentel, et al., report the energy analysis of corn production at different points in time from 1945 to 1970 reflecting the effect of technology changes in the agricultural industry on the energy requirements for produc- tion of the crOp (20). The machinery, fuel, fertilizer, chemical and irrigation requirements and the annual yield of corn production represent national averages. The irrigation requirement assumes that 3.8 per cent of the corn grown in the United States is irrigated. Energy requirements for delivery of supplies to the farm and transportation of the produced corn to its end-use site are included in the analysis. However, the transportation distances are not 144 documented. It is assumed that the transportation distances reflect the national average. The harvested corn is col- lected and dried to 13 per cent moisture content on the farm before delivery to its end-use site. Blankenhorn, Murphey and Bowersox report the energy analysis of forest biomass production by both intensive and caretaker cultural practices (22). Blankenhorn uses the data of Keener and Roller (21) to determine the energy requirements of the intensive system. The intensive system data are then modified to reflect the cultural practices of the caretaker system. Blankenhorn (22) includes the trans- portation requirement to deliver the biomass to its pro- cessing site, where the biomass is dried and chipped. The transportation distance is set at the value which renders the system a zero net.energy producer for trucking, rail and pipeline (50 per cent wood-water slurry) modes of transportation. Table 5.19 lists the transportation dis- tances by truck, rail and pipeline for both intensive and caretaker systems. Both Pimentel (20) and Blankenhorn (22) include energy requirements for human labor in the energy subsidy of crop production. Description of analyses Process analysis is used to determine the energy inputs to crOp production. Pimentel (20) and Blankenhorn (22) determine the physical quantities of capital, raw 145 Table 5.19. Transportation distances for delivery of biomass to processing site (22) Transportation Transportation Distance (mi) Mode Intensive Caretaker Truck 4,887 4,081 Rail 9,974 9,960 Pipeline 36,471 36,422 146 materials and utilities required by the systems completing the first level of energy analysis. This portion of the analyses appear to be complete and accurate. The energy embodied in the raw materials and capital is determined by using embodied energy coefficients reported in the litera— ture. The capital energy input is the portion of the energy embodied in the required equipment which is depleted over the growth period of the crops. Pimentel (20) assumes an equipment life of six years farming an area of 62 acres. Blankenhorn (22) assumes an equipment lifetime of six years farming an area of 10,000 acres (crop density of forest biomass is much less than that of corn). The utility energy subsidy of liquid fuels consumed for crop production is the energy content of the fuel (i.e., the energy subsidy of the fuel is ignored), and the energy subsidy of the electricity consumed is the energy content of the fossil consumed to produce electricity {Pimentel (20) uses national averages of Btu of thermal energy consumed per kilowatt hour produced for the year 1970, Blankenhorn (22) does not report an electrical requirement for production of forest biomass}. Both authors include the energy embodied in human labor in the energy subsidies of the systems. The results of the analyses are presented without the human labor energy subsidy. 147 State of systems outputs The primary product of the system analyzed by Pimentel (20) is corn dried to 13 per cent moisture on the farm and transported (distance not reported) to its end- use site. The primary product of the system analyzed by Blankenhorn (22) is harvested forest biomass transported to a processing site (refer to Table 5.19 for distances) where it is chipped and dried. Neither system reports secondary nor waste products. Energy inputs and outputs of systems The energy inputs reported by Pimentel (20) are listed in Table 5.20 as a function of the year of corn production. Table 5.21 lists the outputs for corn produc- tion reported by Pimentel (20). Table 5.22 lists the energy inputs for intensive and caretaker production of forest biomass reported by Blankenhorn (22). Blankenhorn (22) reports the energy output of forest biomass production as 6 6 212 x 10 Btu/ha-yr and 127 x 10 Btu/ha-yr for intensive and caretaker systems, respectively. Energy parameters of systems Table 5.23 lists the energy parameters of the corn production system analyzed by Pimentel (20) and Table 5.24 lists the energy parameters of the forest biomass production systems analyzed by Blankenhorn (22). 148 Table 5.20. Energy inputs required for corn production reported by Pimentel (20) Energy Subsidy (x 103 Btu/acre-yr) Input i945a 1950a 1954a 1959a 1964a 1970a Capital 714 992 1,190 1,389 1,667 1,667 Raw Materials 506 860 1,372 2,012 2,628 4,662 Utilities 2,402 2,896 3,545 4,066 4,578 5,147 a-Year of crop production Table 5.21. Energy outputs of corn production reported by Pimentel (20) Year of Energy Output Production (x 10 Btu/acre-yr) 1945 13,600 1950 15,200 1954 16,400 1959 21,600 1964 27,200 1970 32,401 149 Table 5.22. Energy requirement for production of forest biomass reported by Blankenhorn (22) Energy Subsidy (x 103 Btu/ha-yr) Input Intensive Caretaker Capital 74 31 Raw Materials 10,077 --- Utilities 201,354 63,420 150 Hmo.o III mam mm.m mmm.om O>8.HH osmH HO0.0 III hOO O0.0 nN0.0H OO0.0 OOOH OO0.0 III OON OO.N OOH.¢H hOv.> OOOH meo.e III mom OO.N mm~.0H 50H.O emmH mOo.o III omm om.m mme.OH mee.e ommH OO0.0 III OOO mn.O OO0.0 NN0.0 OOOH uouomm uouomm HOV chc A HmIOuomO H HmImuomv coHuosponm ucwEmuHsmmm COHumNHHHuD mocOHOHmwm mmumcm Asum OOH xv Adam OOH xv mo Hmmm HmuHomo wouDOmmm mmwwmwm OOumcm mpHmQDO HH 0 umz mmumcm Hmuoa I‘ll {Vi‘ilfliili .I II II , . IIIIIIIIII‘Ii HONO HmucwEHm an pwumHmcm Empmmm COHHUDOOMQ cuoo mo mumumfimhmm Omuwcm .ON.m OHQMB 151 HNNV cuoscwxcmHm On pmanmcm mEOpmwm coHuospoum mmmEoHn ummuow mo mumumfimnmm OOchm OOOO0.0 III OOH OO.H O OO wamumnmu OOOO0.0 III OOH OO.H O NHN O>HmcmucH uouomm Houomm HOV chO A HOIOSV A HmImcv Emummm uCOEOHHOOOm coHumNHHHuD OOCOHOHmmm OOHmcm Asum OOH xv Asum OOH xv HmuHmmO OOHDOOOO mmmooum Omumcm mpamnsm HHmHm>O umz wmumcm Hmuoa .vN.m OHQMB 152 Production of alcohol Comments The controversy surrounding the possibility of a government supported (i.e., through tax credits,etc.) development of a nationwide gasohol program is both energetic and economic in nature. Proponents claim that the use of gasohol will reduce oil imports while providing a market for grain surpluses causing farm prices to stab- ilize and a reduction in the national deficit. Opponents argue that farm prices will skyrocket as a result of the widespread use of alcohol and that the production of alcohol from grain consumes more energy than produced (12). It is not clear as to whether the production of anhydrous alcohol from corn is a net energy producer or consumer, nor can the economic results of a gasohol program be absolutely pre- dicted. Thus, the argument continues as to whether a gaso- hol program should or should not be implemented. However, it is clear that the economics and energetics of gasohol are marginal at best. Gasohol will not solve the United States' liquid fuel crisis. Therefore, a gasohol program should be approached with extreme caution. The marginal energetics of alcohol producing systems are well-illustrated by the numerous variations in the energy analyses applied to the systems. By altering the basis of the energy analysis, the results can render the production of alcohol as either a slight energy producer or consumer. The methodological variations that appear 153 in the analyses available in the literature are outlined below. Specification of system boundary. There is dis- agreement as to whether the energy subsidy of the biomass from which the alcohol is produced should be included in the energy subsidy of the alcohol. The definition of energy analysis states that the energy required to perform any action that would not occur if the system under con- sideration were not in existence must be included in the energy subsidy of the system. It has been suggested that grain motor fuel be produced from distressed grain (13) (i.e., grain that is moldy or has started to sprout). This grain has no food value and, if the distressed grain has no other energy uses, must be considered a waste product of the agricultural system that has no embodied energy (i.e., the use of this "waste" grain requires no additional energy subsidy to the agricultural system). Under these circumstances, the grain itself does not add to the energy subsidy of the alcohol producing system. However, the collection of the distressed grain does require significantly more transportation distance than the quality grain because it is more diffuse than the quality grain (i.e., one per cent of the annual grain production is estimated to be distressed.) 154 Definition of the unit energy equivalence. By defining the energy equivalence as a Btu of crude oil and assuming the alcohol producing system consumes coal or natural gas for the production of required process heat, a significant crude oil savings can be shown through an energy analysis. The definition of the unit energy equivalence is a matter of convention. However, if the same energy equiva- lence is used in the energy analysis of the liquefaction of coal, a much larger oil savings would result. Limiting the definition of the unit energy equivalence to only one of the non-renewable energy resources is of no use in energy analysis. If the energy equivalence is applied consistently to the energy alternatives under consideration, the same conclusion from comparisons of alternative energy supply systems will result. Furthermore, the use of the limited energy equivalence can distort the interpretation of the results of an analysis when examined without reference points. Definition of the quality of energy contained in alcohol. Some authors claim that the fuel efficiency of alcohol, in terms of miles per Btu of energy contained in the fuel, is greater than that of gasoline (13). If this claim is valid, it should be considered in the comparison of the energetics of alcohol and gasoline. The non- consideration of the fuel efficiency difference between gasoline and gasohol is not a shortcoming of the convention 155 for assigning energy equivalences to the outputs of the system, but rather a result of the definition of the out- puts of the system (i.e., the specification of system boundary). If the output of the system is defined as a liquid fuel, the alcohol is not of a higher quality than any other liquid fuel. However, if the output of the system is specifically defined as the mechanical energy output of transportation (i.e., the displacement of mass over a distance), the quality of the energy contained in the alcohol would automatically be accounted for. Definition of the energy outputs of a system. There .is disagreement as to whether the secondary products of the system should be considered as energy outputs and as to how this energy should be accounted for. This question stems from a misunderstanding of energy analysis in the sense that the energy analysis applies to a system and not to its products. Thus, if a system produces a material which is considered an energy product, it should be included as an energy output of the system. Analyses appear in the litera- ture in which the energy embodied in the secondary products is subtracted from the energy subsidy of the system(12). Since the secondary product cannot actually displace energy inputs to the system, its energy content should not be subtracted from the energy subsidy. The question concerns the distillers dark grainsproduced as a by-product of grain fermentation. The product is sold as cattle feed, a food product, which is an energy product. 156 Description of systems Hopkinson and Day (14) report an energy analysis of alcohol produced from sugar cane grown in Louisiana. Three systems are considered in which all the sugar cane residue (bagasse) is converted to steam (exceeds process heat requirement), enough bagasse is converted to steam to supply the process heat requirements, or the process heat is supplied by fossil fuels. Hopkinson and Day (14) ignore the by-products of the system and the transportation requirement for distribution of the alcohol. DaSilva, et al., report an energy analysis of three crops, sugar cane, cassava and sweet sorghum, that are being considered for alcohol production by the National Alcohol Program (PNA) in Brazil (15). The energy require- ments for crOp production are based on cultural practices followed in Brazil and are less energy intensive than American cultural practices. The process heat is supplied by consumption of bagasse for sugar cane and sweet sorghum, and by fossil fuels for cassava. DaSilva (15) ignores the energy requirements for distribution of alcohol, the energy embodied in by-products of the system and the energy embodied in the alcohol plant itself. Chambers, Herendeen, Joyce and Penner (12) report the energy analysis of alcohol produced from corn. Energy inputs and outputs are reported for a base case alcohol production system which represents national average market 157 corn {energy inputs determined by Penner and Joyce (16)} and a conventional alcohol production process{energy inputs determined by Scheller and Mohr (17)}. The base case system credits the outputs with the energy embodied in the corn normally used as cattle feed that is displaced by the distillers dark grains by-product (as opposed to the enthalpy of the distillers dark grains). The energy required to distribute the alcohol and the energy embodied in the alcohol plant are ignored. Chambers, et al., (12) determine the effects of various system modifications on the energy inputs required for production of alcohol from corn. Hopkinson (14) and DaSilva (15) do not include a cooking operation in the industrial process since the crops analyzed are naturally fermentable sugars. Chambers (12) includes the cooking Operation in the process as is required for production of alcohol from corn. Table 5.25 lists a brief description of the systems analyzed. Description of analyses The energy analyses mentioned almost exclusively rely on process analysis for determination of energy inputs required for the production of crops. Only the analysis by Hopkinson and Day (14) includes the energy embodied in the alcohol plant. However, neither the methodology used to determine the energy embodied in the plant nor the value obtained are reported. An analysis by the ACR Process 158 Table 5.25. Description of systems analyzed Author System Description Hopkinson 1 Conversion of all bagasse to steam 2 Conversion of enough bagasse to steam to supply process heat 3 Supply of process heat from fossil fuels DaSilva 4 Sugar cane 5 Cassava 6 Sweet sorghum Chambers 7 Base case (corn) 8 Process of ACR (18) that is reported to require less process heat 9 Burn cobs and stalks to supply portion of process heat 10 Assume enthalpy of distillers dark grains as its energy content 11 Systems 9 and 10 12 Systems 8, 9, and 10 159 Corporation (18) reports the energy embodied in the alcohol plant to be 7000 Btu/yr compared to a total energy subsidy of 304,000 Btu/yr. Thus, neglecting the energy embodied in the alcohol plant is not a significant source of error. The energy required for crop production has been widely studied and is well documented. Hopkinson (14) and DaSilva (15) rely on the data of Heichel (19) and Pimentel (20) while Chambers, et al., (12) have generated the agricultural energy input independently (16). The process energy requirements are mainly fuel requirements for generation of steam. However, it is not clearly stated in any analysis that the process fuel requirements represent the energy content of the fuels only, or that the energy subsidy of the fuels is included as an energy input. Since such a large amount of fuel is consumed in the production of alcohol, the energy subsidy of the fuels could be a significant energy input. The option of displacing fossil fuels with crop residuals for generation of process heat is considered in all the analyses. If this Option is chosen, additional energy inputs are required for the harvesting, collection and transportation of the residues that are normally left in the field. Only Chambers (12) accounts for this addi- tional energy subsidy by assuming that half of the energy content of the crOp residue is productively available. There is also the question of the technical feasibility 160 of utilizing crop residues due to the possibility of soil depletion (12). The analyses by Hopkinson (14) and DaSilva (15) include the energy embodied in human labor required for crop production in the energy subsidy of the system. Human labor is now considered a free energy resource in an energy analysis. However, determinations of energy required for crop production often include human energy inputs. The human labor energy input is an insignificant contribution to the total energy subsidy of alcohol production and does not effect the results of the analyses. The unit energy equivalence is defined as a Btu of thermal energy in all analyses reported. State of systems outputs In all systems, the primary product is non-delivered anhydrous ethyl alcohol. In the systems analyzed by Hopkinson (l4) and DaSilva (15), a by-product of non- delivered steam is produced. The systems analyzed by Chambers (12) include a dried (to 15 per cent moisture) non-delivered distillers dark grains by—product that is sold as cattle feed. Energy inputs and outputs of systems Table 5.26 lists the energy inputs and outputs of alcohol producing systems reported by the various authors. 161 ON.m OHOMB CH pmumHH mcoHumHuommp Emumwm I m OO.vm OO.H ON.NO NH OO.vm O0.00 ON.NO HH OO.vm HO.vO ON.NO OH OO.NO O0.00 ON.NO O OO.NO OO.HN ON.NO O ANHO OO.NV H0.00 ON.NO O .HO um ImeQEan OH.OHH III OO.HO O OO.Nm ON.OO HN.OH m AOHO O0.00H III Nv.OH O .HO um .m>HHmmo N0.0> OO.NO O>.OO O N0.00 OO.H O0.00 N AOHO oo.OOH mm.H me.mm H .H8 um .comcdeom AumIm:\sum OOH xv mmmooum HOHSHHOOHHOO mEOummm Honusd mpnmuso mmumcm Humlmn\sgm OOH xv musmcH Omumcm mEmumOm OCHOSOOHQ HOSOOHO mo musmuso paw mHDQcH Omuwcm .ON.O OHQOB 162 Energy parameters of systems Table 5.27 lists the energy parameters of the various systems analyzed. The resource utilization factor (which is zero for these systems) and the capital require- ment factor (requires the capital energy subsidy for calculation) are not listed for the systems analyzed. Direct conversion of solar energy to electricity Wind energy See analysis included in summaries of comprehensive energy analysis studies. Ocean thermal energy See analysis included in summaries of comprehensive energy analysis studies. Photovoltaics Comments. There is optimism among researchers currently involved in the field of solar energy that photo— voltaics will eventually emerge as a significant supplier of electricity (34). However, the current method of producing photovoltaic cells is both economically and energetically expensive. There is general agreement that a technical breakthrough is required in the manufacture of photovoltaic cells before the concept will be a viable energy supplier. However, a photovoltaic power pilot plant is now under construction in Saudi Arabia which will be useful in obtain- ing performance data (34). 163 .mN.m OHQOB CH pwumHH coHumHHommp Emummm I m OOH OO.H O0.0N HN.OO NH Oh O0.0 OO.OHI O0.00 HH Om Om.O OO.NvI OH.OO OH HO H0.0 OO.ONI O0.00 O OO O0.0 OO.OHI O0.0m O .Hm um vv Ov.O NO.va OH.>O h .menEmcu HOO H0.0 O0.00 OO.HO O OHH OH.H ON.> O0.00 O .HO um mHO mH.O Hm.em NH.OH e .m>HHmco mO O0.0 OO.OI O0.00 O OON OO.N O0.00 N0.00 N .Hm um mmm mm.m OO.HO mm.mm H comcerom HOV CHOU A Hmrmn O A HOIms v Emumwm Honunfi mocmHOHmmm mmuwcm Asum OH xv Asum OH xv mmmooum mwumcm mummnsm HHmHm>O Hmz hOHOcm HMHOB mEmumOm OCHODUOHQ HO£OOHm mo wumumfimumm mmnmzm .ON.m OHQOB 164 Description of systems. Gandel and Sears (4) have estimated the power consumption of manufacturing processes for the fabrication of silicone, cadmium sulfide and gallium arsenide photovoltaic cells. Considering the production of cells as a continuous process, the power requirements reported by Gandel and Sears (4) are the rate at which fuels and electricity are consumed by the system. Thus, the power requirements do not include energy embodied in raw materials or capital. Furthermore, the energy embodied in electrical interconnects, solar array mounting structure and power conditioning equipment, which are needed to obtain useful energy from the cells, are not considered by Gandel and Sears (4). The system to which energy analy- sis is applied is actually the manufacturing of photovoltaic cells and not a photovoltaic power station. However, it has been suggested (2) that the utility energy subsidy is the major portion of the total energy embodied in photovoltaic cells. Thus, the utility requirements for the fabrication of photovoltaic cells approximately represent the energy embodied in the cells. By considering the output of the cell manufacturing process to be the potential power produc- tion capability of the cells produced, energy parameters of the fabrication process can be calculated. These parameters will give insight into the energetics of the generation of electricity from solar radiation via photovoltaic cells. 165 Description of analysis. The power requirements for fabrication of various photovoltaic cells reported by Gandel and Sears (4) are estimations of the rate of fuels and electricity consumed by a conceptual manufacturing process. Comparison of this quantity of energy to the potential energy output has little significance unless the utility energy subsidy for production of the cells is also the major portion of the total energy subsidy of the photovoltaic power station. Gandel and Sears (4) do not separate the power requirement of cell manufacture into thermal and electrical energy requirements. The power requirement is assumed to be the rate of consumption of thermal energy. Thus, the unit energy equivalence is defined as a Btu of thermal energy. State of the systems outputs. The products of the systems analyzed are various photovoltaic cells. The energy output of the system is considered to be the potential energy producing capability of the photovoltaic cells. Energy inputs and outputs of systems. Table 5.28 lists the energy consumed during a one-year period of cell manufacturing, the power producing capability of the cells produced during that year and the estimated lifetime of the cells. 166 Table 5.28. Energy requirements and potential energy outputs of photovoltaic cells manufactured during a one-year period Produced 5213:3888 EEWEE-I-t Cell Cell 10 p 13 1 y Lifetime Material (x 10 Btu) (x 10 Btu/hr) (yrs) Silicone 13,676 2,691 10 Cadmium 17,532 5,382 5 Sulfide Gallium 173 60 10 Arsenide Energy parameters of the system. Table 5.29 lists the energy parameters of photovoltaic cell production. 167 .mHHmo onuHo>ouosm OCHNHHHOD Emummm OCHOSUOHQ OHHOHHHOOHO cm mo mHmuOEmnmm OOHOOO pcm OpHmnsw OOHOQO may ou uHEHH HO30H m ucmmwumwu .HO>O30£ .OO OOLE .OchmmE Hmmu o: O>m£ .muommumcu .Ocm Ewummm OCHODUOHQ OOHOCO cm ou HOOOH nos 00 mHmuOEOHwQ OOHOGO 0:9 I m mpHcmmH« III OOO Ov.O ONO OOH EDHHHmU OOHHHDO III OOH OO.H OO0.0 NOm.nH EDHEOOO III emH sm.H Nmm.mH www.mH chOHHHm Houomm HOV CHOU Adam OHOH xv Asum OHOH xv Hmwuwumz COHWMMMWMWD wocmHonmm OOHOcm OOHmcm OOHmnnm HHOO m mmOOOHm HHMHO>O umz mmumcm Hmuoe mmHHmo 0HmuH0>OHOLQ mo COHHODOOHQ Opp mo mHOpOEMHmm mmumcm .ON.m OHQMB 168 Summaries of Comprehensive Energy Analysis Studies Energy Supply Systems Based on Fossil Fuels Comments The United States' energy supply systems are based mainly on fossil fuels with small contributions from light water nuclear reactors and hydroelectric power stations (35). For all practical purposes, proposed alternative energy technologies must be able to compete with a fossil fuel based counterpart. Thus, it is necessary to develop the energy parameters of all fossil fuel based energy supply technologies at a high level of confidence. Fossil fuels have a high energy content per unit volume. Thus, the capital energy subsidies for the extraction, transportation and processing of the fuels are relatively small compared to the energy produced. In order to determine the utility and raw material energy subsidies of fossil fuel based energy supply systems, data regarding the operation of fos- sil fuel processing systems are required. Unfortunately, these data are generally unavailable due to proprietary reasons making accurate energy analyses of fossil fuel based energy supply systems difficult. Mechler, et al., (28) report specific utility and raw material requirement data as well as general capital cost data of numerous Operations associated with fossil fuel based energy supply systems. The energy inputs and outputs of each operation are determined independently allowing the 169 calculation of the energy parameters of many energy supply systems through the combination of separate operations. The study by Mechler (28) is the only comprehensive evalu— ation of fossil fuel based energy supply systems that ap- pears in the literature. The results reported by Mechler (28) are used to determine energy parameters which serve as the reference point for the comparisons between alternative and conventional energy supply technologies that are discussed in this study. Description of systems and state of systems outputs By combining separate processing, extraction and transportation systems, Mechler (28) develops trajectories which trace various fossil fuels to various end uses. Table 5.30 lists the trajectories developed by Mechler (28). Description of analysis The first level of the energy analysis reported by Mechler (28) (i.e., the quantitative determination of utility, raw material and capital requirements of the name- plate processing system) is acceptable. The determination Of utility requirements appears to be complete and accurate. Selection of the required raw materials and capital that represent non-negligible energy inputs to the system is based on the experience and judgment of the researcher. Therefore, while the determination of raw material and capital requirements is not complete, the energy embodied 170 Table 5.30. Description of fossil fuel trajectories analyzed by Mechler (28) 1) Production of non-delivered raw coal, one-half surface and one-half underground mined. 2) Delivered product of trajectory l), transported by rail 500 miles. 3) Production of non-delivered crude oil (represents national average of domestic oil wells). 4) Delivered product of trajectory 3), transported by liquid pipeline 300 miles (national and regional average). 5) The production of natural gas gathered by pipeline at the well field and dried at a gas liquids plant (represents national average of natural gas production). 6) Delivered product of trajectory 5), transported by pipeline 1000 miles (national and regional average). 7) High Btu pipeline gas produced using coal from trajectory 1), gasified by the Lurgi process at the mine site, trans- ported 1000 miles by pipeline (national and regional average) and distributed by pipeline. 8) Gasoline produced using crude oil from trajectory 3), transported 300 miles by pipeline (national and regional average), refined (regional average) and distributed 70 miles by truck (regional average). 9) Gasoline produced using raw coal from trajectory 1), liquefied at mine site, transported 600 miles by pipeline, refined and distributed 70 miles by truck (regional average). 10) Gasoline produced using oil shale, one-half surface and one-half underground mined, crushed and retorted above- ground (regional estimate), refined (national average) at mine site, transported 300 miles by pipeline (national average) and distributed 70 miles by truck (regional average). 11) Electricity produced using crude oil from trajectory 3), desulfurized and converted (national average) near well site and transmitted 150 miles (regional average). 171 Table 5.30 (Cont'd.) 12) Electricity produced using natural gas from trajectory 6), converted (national average) and transmitted 150 miles (regional average). 13) Electricity produced using coal from trajectory 2), converted (national average) and transmitted 150 miles (regional average). 14) Electricity produced using pipeline gas (from coal gasification using the Lurgi process) from trajectory 7), converted (national average) and transmitted 150 miles (regional average). 15) Electricity produced using coal from trajectory l), liquefied at the mine, transported 300 miles by pipeline, converted (national average) and transmitted 150 miles (regional average). 16) Electricity produced using oil shale, one-half surface and one-half underground mined, crushed and retorted aboveground and converted at the mine site and transmitted 150 miles (regional average). Note: Refer to reference (28) for details concerning the modules comprising the trajectories. 172 in the reported raw materials and capital is presumably an accurate representation of the raw material and capital energy subsidies. Utility requirements are reported as rates of fuel consumption and raw material and capital requirements are generally reported as dollar costs. The utility energy subsidy is taken as the energy content of the required fuel and electricity and the raw material and capital energy subsidies are determined using a crude application of input-output methodology (i.e., trade and transportation margins are ignored and an average energy intensity coefficient is often used). As a result, the energy subsidy of each separate system (i.e., module) is systematically underestimated. This underestimation can cause significant error if a large portion of the utility requirement is electricity. The inappropriate use of the input-output analysis is acceptable since the raw material and capital energy subsidies are usually not a large fraction of the total energy subsidy (a characteristic of fossil fuel based systems). The results of the energy analyses are reported as a total energy subsidy required per unit energy input of feed to the module for each module analyzed. The modules are then combined into trajectories tracing a fossil fuel in the earth to an end-use product. The total energy subsidy of the trajectory is the summation of the energy 173 subsidies of each module with the contribution from each module proportional to the energy input to each module. The assumption of prOportionality between the energy subsidy and the size (i.e., energy throughput) of a module may not be accurate,especially for modules with large capital energy subsidies. Some of the modules analyzed have multiple energy products such as crude oil refineries. Such modules are analyzed similarly to single product modules with the result reported as an energy subsidy and energy output (summation of all energy products) per unit energy input of feed to the module. The reporting of results in this manner assumes that all energy products of a module have the same energy subsidy per unit energy content, and are produced at the same energy conversion efficiency (thermal efficiency). Energy inputs, outputs and energy parameters of systems Table 5.31 lists the total energy subsidy, gross energy output and energy parameters of various fossil fuel based energy producing systems. 174 .OO.m OHQOB CH pOumHH COHOQHHOOOU OHOHOOOOHO OCH ou mHOOOH HOCOOHQ OCH HOHHO HOCECC OOCOHOMOH OCBIO m.mo~ NO.H mm.mH m.m O.HmH s.Hm OHsuHoHuHomHm s.mmH mm.m HN.OH m.m m.OOH e.mH mHsuHoHuuomHm O.mmH eH.m em.mH e.m H.msH m.om HHHHHoHuHomHm e.sm~ sm.m ~m.m~ s.m m.OON e.em mHsuHoHuuoon e.osm os.m NN.ON O.m H.amm m.Hm mHsuHoHuuomHm e.emm OH.H HO.HN a.m «.mmm o.mm HHsuHoHHHomHm O.mmO mm.H se.em m.O m.cmm m.Om OHmcHHOmmu m.osO me.H OO.OO s.O m.oem m.mm mmcHHommO m.oom HH.H OO.HO c.0H m.OHm m.mm mmcHHOmmO m.eHO HO.H mo.om m.mm o.Hmm m.mm hmac mcHHmnHm O.mmm HH.H mm.~m m.mm s.mmm m.mm Ommu Hmusumz s.m~m OO.H OO.HO m.ee o.mom s.o~ mmcw Hmucumz «.mem HO.H mv.mm o.Hm m.mmm so.mH eHHo «.msm HO.H so.mm O.mm m.mmm m.sH mHHo c.000H OO.H mm.em «.me m.Oem e.m~ NHmoo c.000H OO.H mm.mm m.mNH «.mmm m.s HHmoo IE, 8 ing 8.2%: any as: 8 Es, 8 pmmwmw .OOHOOWOO OWOOOHO mmuOcm qu OOHOCMOMMMMM HHOHO>O AONV HuCOEOHHCOOH OOHCOOOH H>\sum OOH x H Co UOmmC OHO mOHHOHOOnOHu HHOV mOms OCO OCOHHO> mo mEHOu CH mOOHCOmOH HOCO HHOOOM mo OHOOOEOHOQ OOHOCM .HO.m OHQOB 175 Ocean Thermal Energy Conversion (OTEC), Wind Energy, In-situ Oil Shale Processing, Fluidized Bed Coal Combustion Versus Conventional Coal Combustion and Municipal Waste Disposal Comments Perry, et al., (29) report the energy analyses of the following energy supply (or savings) systems: 1. Ocean Thermal Energy Conversion (OTEC); 2. Wind Energy; 3. In-situ Oil Shale Processing; 4. Atmospheric Fluidized Bed Coal Combustion; 5. Pressure Fluidized Bed Coal Combustion; 6. Conventional Coal Combustion; 7. Municipal Waste Disposal. The analyses are significant not only because they are the only analyses found in the literature applied to the listed systems, but also because the analyses represent the state of the art method of energy analysis. The methodology developed by Perry, et al., (29) at the Insti- tute for Energy Analysis (Oak Ridge Associated Universities) is the basis of the energy analysis methodology suggested in this study. Description of systems and state of systems outputs System 1 - OTEC Description. The system is based on a conceptual design by the Lockheed Missiles and Space Company. The 176 system is designed to Operate at a rated output of 169 MW(e) at a capacity factor of 90 per cent over a lifetime of 35 years, located in tropical waters 20 miles off shore. The system incorporates the Rankine power cycle with ammonia as the working fluid and uses titanium heat ex- changers. The system is designed to feed an electric grid as a base-load power station. The design includes trans- mission lines for the underwater DC transmission of electricity to the grid (a 9 per cent transmission loss is assumed). State of outputs. The system produces base—load electricity delivered to an on-shore electric grid. No secondary or waste products are reported. System 2 - wind energy Description. The system is based on General Electric's design of a horizontal axis, two blade rotor rated at 1500 kw(e) (at a wind velocity of 22.5 mph) Operating at a capacity factor of approximately 50 per cent over a lifetime of 30 years. The system is designed to operate in a fuel saver mode and does not include energy storage facilities. The design does not include trans- mission lines for transmission of the electricity. However, a 9 per cent transmission loss is assumed during the distribution of the electricity. The system is designed for unattended operation in a location with suitable wind conditions (including an 18 mph mean wind velocity). 177 State of outputs. The system produces delivered electricity in the fuel saver mode. The system has no secondary or waste products. System 3 - in-situ oil shale processing Description. The system is based on a computer simulated design of a room and pillar modified in-situ process prepared by Fenix and Scisson, Inc. The oil recovery system is estimated to produce 50,000 barrels of oil per day from 20 gallons per ton Green River oil shale over a lifetime of 17.7 years. The design does not include facilities for disposal or processing of excavated shale, nor for the prerefining of the recovered oil to a crude oil equivalent. State of outputs. The system produces 50,000 barrels per day of a crude oil (not equivalent to petroleum crude oil) at the mine site. Secondary products of oil contained in excavated shale or the low-Btu gas produced are ignored. The system has no reported waste products. Systems 4, 5 and 6 - atmospheric (AFB) and pressurized (PFB) fluidized bed coal combustion and conventional coal combustion, respectively Description. The systems, which are designed to produce electricity delivered to a utility grid, are based on design evaluations prepared by the General Electric Company (ECAS Phase II). The AFB and PFB systems produce 178 steam that is fed to an advanced steam cycle, whereas the conventional system supplies steam to a conventional steam cycle using stack gas scrubbers to remove 802 from the effluent gases. Each system is designed to operate on No. 6 Illinois coal (delivered 300 miles at an energy cost of 970 Btu primary/ton-mile)at a capacity factor of 65 per cent over a lifetime of 30 years. The systems' designs assume a 9 per cent output loss for the transmission of electricity but the designs do not include transmission facilities. Each system is rated at 747 MW(e). State of outputs. The primary outputs of the systems are delivered electricity (intermediate to peak load). The analyses neglect secondary products. Facilities for handling of waste products are included in the design. System 7 - municipal waste disposal Description. The system is based on a Tennessee Valley Authority feasibility study for recovering energy intensive residuals from processed solid municipal wastes as a substitute fuel for electric power generation. The system is estimated to process 2000 tons of raw solid wastes per day over a lifetime of 20 years Operating in a fuel 6 Btu of thermal energy displacement mode saving 11.1 x 10 per ton of solid wastes processed. The system design includes the transportation of wastes from regional col- lection centers to the processing plant (assumed to be 150 miles by train) that is located within 20 miles of a 179 landfill site. The waste processing produces energy out- puts of a fuel and reclamation of energy intensive mater- ials, as well as a condensed waste for the landfill. The system design includes the transportation of the fuel to the electric power station (30 miles by truck) and modifi- cations of the power station required to utilize the fuel. Delivery of the recovered materials to a reclamation plant is not included in the system design. State of outputs. The system displaces the mining and transportation (150 miles by rail) of coal required for power production at a steam plant and recovers energy intensive materials (not delivered to a reclamation plant) from processed solid wastes. Facilities are included for the disposal of the condensed waste. Description of analysis The methodology applied by Perry, et al., (29) is the basis of the methodology suggested in this study. Energy inputs, outputs and parameters of systems Table 5.32 lists the total energy subsidy, the energy output and energy parameters of the systems analyzed by Perry (29). 180 .pOuHomOH OOC HOOOEOHOQ mo COHHOHCOHOO COO OOHHDOOH CoHuOEHOMCH I m . III . x . x . NHOHxOH O OOOH OO OH NHOH OO O HHOH OO O O OHOHxHO.H Ov.O ON OO.v OHOHxOO H NHOHxOO N O OHOHxHO.H OO.N vO O0.0 OHOHxHH.H NHOHxOO H m OHOHxHO.H OH.O HO OH.O OHOHxNH.H NHOHxOO H v OHOHxOH.H m m O0.0 OHOHxNO.O OHOHxON H O OHOHxNO.N III OOOO O0.00 OHOHxOO.H OOHxOH m N NHOHxOO.O III OOO O0.0 NHOHxON O HHOHva m H AHOVdumv Houomm HOV CHOO A MN A HNI v EOumNm psmuso COHHONHHHHD OOCOHOHOmm OOHOCm AOHOEHHQ Cumv AOWOEHHQ,CumO OOHOCm OOHCOmOm mmOOOHm OOHOCm OOHOCCO HHOHO>O qu OOHOCm HOHOB HONO OHHOm >3 OONOHOCO OEOHOOO mombsmuso OCO OHOOOEOHOQ OOHOCm .NO.m OHQOE 181 Nine Electricity Generating Systems Comments Pilati and Richards report the energy analysis of nine systems producing electricity from fossil fuels (coal, natural gas, crude oil and oil shale) and nuclear fuels (30). The results of this analysis should either reinforce or add suspicion to the results of the analysis by Mechler (28). However, even though the bases of the analysis are discussed, the details of the analysis are not documented. Thus, the results of Pilati and Richards' analysis (30) cannot be quoted with an acceptable degree of confidence. Description of systems Table 5.33 lists descriptions of the systems analyzed by Pilati and Richards (30). Description of analysis The analysis is unique in that it is the only analysis completely automated. The approach to determining the energy subsidy of an energy supply system comprised of individual facilities is very similar to the approach of Mechler (28). Pilati (30) determines the capital and operational (i.e., utility and raw material) requirements per unit energy output as well as an energy conversion efficiency (i.e., per cent of feed converted into energy output) for each facility. This approach to energy analysis is the application of process analysis to all facilities 182 Table 5.33. Description of systems analyzed by Pilati (30) Resource System Definition System Coal Coal Mine + Coal Fired Power Plant 1 Coal Mine + Coal Gasification + Gas 2 Natural Gas Crude Oil Oil Shale Nuclear Fired Power Plant Coal Mine + Combined Cycle Power Plant 3 Coal Mine + Solvent Refined Coal + 4 Coal Fired Power Plant Gas Production + Gas Utility + Gas 5 Fired Power Plant Crude Oil Production + Low Gas 6 Refinery + Oil Fired Power Plant Oil Shale Mine/Retort + Low Gas 7 Refinery + Oil Fired Power Plant LWR Fuel Mining/Processing + LWR 8 Power Plant HGTR Fuel Mining/Processing + HGTR 9 Power Plant 183 comprising the horizontal trajectory (feed trajectory) of the entire system. The capital and operational require- ments are mapped into appropriate sectors for application of input-output analysis and entered into a computational program along with the energy conversion efficiency. The program computes the energy subsidy per unit energy output of each facility through application of energy intensity coefficients. The required energy output of each facility is calculated using the energy conversion efficiency of each facility based on a total system output of 1 Btu thermal energy. In other words, the energy conversion efficiency of the last facility in the horizontal trajectory of the system gives the energy input to that facility based on a total system energy output of 1 Btu thermal (i.e., the last facility in the trajectory has an energy output of l Btu thermal). The energy input to the last facility is the energy output of the preceding facility. Thus, the energy output and the feed energy input of each facility in the trajectory can be calculated from the energy con- version efficiency of each facility. The energy subsidy contribution from each facility to the energy subsidy of the entire system can then be calculated from the energy output of each facility. In order to automate the use of the energy intensity coefficients generated for the application of input-output analysis, the data of capital and operational requirements fed to the program must be of a specific form and represent 184 a specific value (refer to discussion of input-output methodology). Pilati and Richards (30) do not describe how the data are manipulated and only indicate the data source. Furthermore, Pilati and Richards (30) indicate that the accuracy and consistency of the data are suspect. The system trajectories developed by Pilati and Richards (30) are incomplete in that required transportation facilities are neglected. The unit of the energy equiv- alence is defined as a Btu of primary energy. State of systems outputs The only product of each system analyzed is distributed electricity. Energy inputs and outputs of systems Table 5.34 lists the lifetime capital, operational and feed energy requirements per Btu lifetime energy out- put of the systems analyzed. Table 5.34. Lifetime energy requirements per 185 Btu lifetime energy output of systems analyzed by Pilati and Richards (30) Lifetime Energy Requirements Capital (Btu Primary System (Btu Total Output) 1 2 0.02 0.04 0.01 0.03 0.04 0.08 0.03 0.42 0.69 Operational ) (Btu Primary 0.13 0.32 ) (Btu Total Output) Feed (Btu Primary 4.02 ) (Btu Total Output) Energy parameters of systems Table 5.35 lists the energy parameters of the electricity-generating systems. 186 OO0.0 ON.O OH OH.H NH.O O0.0 O HNv.O NO.v NN OO.H O0.0 O0.0 O NO0.0 NO.v OH OO.H ON.O N0.0 O HO0.0 O0.0 ON ON.H OH.O H0.0 O OO0.0 O0.0 ON OO.N N0.0 Ov.O m ON0.0 ON.O OH OO.H Ov.O Om.O v OH0.0 OO.N OO O0.0H O0.0 O0.0 O OO0.0 O0.0 OH OO.N O0.0 O0.0 N OH0.0 O0.0 HO N0.0 O0.0 OH.O H HOHOOO Houomm HOV CHOU A usmuno :umv A usmuso sumv EOumhm pCOEOHHCqOm COHOONHHHHD OOCOHOHmmm OOHOCm AOHOEHHO sumv AOHOEHHO Cumv HOHHQOU OOHCowOm mmOOOHm OOHOCM OUHOQCO HHOHO>O qu OOHOCM Hmuoe AOOO OOHOCOHO OCm HucHHm On OONOHOCO mEOuwmm mo OHOuOEOHOm OOHOCM .O0.0 OHQOB CHAPTER 6 CONCLUSIONS, IMPLICATIONS AND RECOMMENDATIONS Introduction The results of energy analyses, when reported as suggested in Chapter 3, offer information that is useful in developing competent energy policies. Energy analysis results give insight into the behavior of energy supply systems on three levels of policy planning. The first level deals with the operation of individual systems as predicted by the absolute values of the energy parameters of the system. The evaluation of energy parameters in this context investigates the sensitivity of the system energetics to energy inputs which are extremely site specific or which dominate the total energy subsidy of the system. A discussion of this level of energy analysis implications is presented for the analyses performed by the author (central receiver solar thermal power station, solar industrial process heat, crOp production and production of ethanol from corn) and for the energetics of nuclear power plants and the supply of energy from fossil fuels. The second level of energy analysis implications considers the supply of energy for specific end uses. This evaluation of system energetics is a relative 187 188 comparison of systems competing for the supply of a specific energy product (usually a comparison of alter- native and conventional energy supply systems). This level of energy analysis implications will not only match the optimal energy supply system to a specific energy product, but will also indicate if the service performed by the energy product can be performed more efficiently (with the expenditure of less energy) in an alternative manner obtaining the same goals from a different energy form (such as the use of electricity instead of liquid fuels for transportation). It is in this context that the United States' transportation needs and the supply of electricity and heat are discussed. The information base necessary to develop a competent national energy policy is not complete without an examination of the first two levels of energy analysis implications. Furthermore, a tool is needed to predict the behavior and the future consequences of proposed energy policies. Thus, a dynamic supply and demand model capable of describing a complex network of energy supply systems based on information obtained through the first two levels of energy analysis implications must be developed. This model will define the third level of energy analysis implications. A discussion of the general characteristics of a future energy supply scenario based on the results of the first two levels of energy analysis implications and 189 a description of the basis for a dynamic energy supply and demand model are presented. Finally, recommendations for further efforts in energy analysis are discussed. First Level of Energy Analysis Implications Solar Energy Comments In the near future, alternative energy supply systems will be called upon to reduce crude oil and natural gas consumption in the supply of energy to both industrial and residential sectors of the United States. One indi- cator of a healthy industry in a capitalistic society is the continuous growth of the industry's output and profit. As an industry's productivity increases, its consumption of energy, directly and indirectly (i.e., through the use of capital, raw materials and feed stocks), increases as well. Thus, the energy supply systems Of a capitalistic society must produce enough net energy to both satisfy the consumption demands of the society and to re-invest in the construction of new energy supply facilities to allow the growth of the society. Consider the growth capability of energy supply systems based on the following crude model: Assume nO units of an energy supply system exist. Each unit has a specified output, as well as a specified 190 energy subsidy requirement. Define the energy flows and system properties of each unit as follows: E The annual energy output of each unit out E0 5 The annual energy subsidy required by p each unit excluding the amortized capital energy subsidy X g The capital requirement factor of each unit L E Lifetime of each unit Eav (n) E The energy made available during one year of Operation from n existing units G E Energy gain of each unit gmax EiMaximum growth rate of the energy supply system Recall the definition of the energy gain G E E:out Eop + x . Eout Eav (n) is given by E (n) =r1(EO -E) av C ut p 1 The energy made available during the first year of operation is given by _ _ l Eav (no) — no Eout (1 G + X) The maximum growth rate of the energy supply system is given by n max gmax _ i o E (n ) nl max = av . X . Bout L = (1 — l + X) gmax G 191 Generally, solar alternatives to fossil fuel based end uses of energy are lower gain systems often with higher capital requirement factors and similar lifetimes. Thus, complete displacement of crude Oil with solar alternatives may not be acceptable from a growth capability vieWpOint. Although solar energy supply systems are generally lower gain systems compared to their fossil fuel based counterparts, solar energy supply systems operate at a higher overall process efficiency because the energy content of the energy product is freely available. Thus, there is much less energy embodied in the energy products of systems based on solar energy than the energy products of fossil fuel based systems. This result implies that solar energy alternatives can be utilized to effectively reduce the consumption of fossil fuels in the supply of the same energy products. Specifically, the use of solar energy supply systems can reduce the consumption of crude oil without the increased consumption of other fossil fuel resources. The fact that solar energy supply systems are generally low gain systems suggests that at least a portion of the system's energy subsidy must originate from fossil fuels to render an adequate portion of the system's energy output available for end-use consumption. Thus, solar energy supply systems can be expected to reduce rather than displace fossil fuel consumption. The above mentioned characteristics of solar energy supply systems suggest the 192 use of such systems in an interim energy supply role allowing the reduction of crude oil and natural gas consumption without the increased consumption of domestic coal resources. The reduction of crude oil and natural gas consumption without the increased consumption of coal will allow the investment of coal for the development and implementation of an acceptable long-term energy supply system that will ultimately displace the consumption of fossil fuels, such as the nuclear breeder reactor. Central receiver solar thermal power stations Two individual system designs of a central receiver solar thermal power station are analyzed as described in Appendix A. The major difference between the two system designs is the design philosophy adopted to achieve the lowest possible capital investment with regard to the collector subsystem. The design philosophy of the collector subsystem in system 1 is to maximize the efficiency of the collector subsystem and thereby minimize the total reflec- tive surface area required. The design philosophy of the collector subsystem in system 2 is to minimize the cost of the components utilized in the collector subsystem which results in an increase in the total reflective surface area required. System 1 requires a total of 68,500 square feet of reflective surface area per MW(e) system output (20), while system 2 requires 74,475 square feet of reflective surface area per MW(e) system output (21). However, system 2 requires 193 only three receivers and towers per 100 MW(e) system output compared to the ten receivers and towers required by system 1 per 100 MW(e) system output (9). The energy parameters favor the design philosophy of system 2 based on the assumption that both systems have the same lifetime (9). If the use of lower quality components results in a system lifetime of twenty years compared to a system lifetime of thirty years resulting from the use of high quality components, the energetic advantage indicated by the energy parameters of the system utilizing the lower quality components (based on the assumption of equal lifetime) is lost (9). The capital energy requirement represents 87.7 per cent and 88.4 per cent of the total energy subsidy of systems 1 and 2, respectively (assuming a 1000 mile transportation distance for delivery of prototype components, a system lifetime of thirty years and including the elec- tricity fed back into the system in the energy subsidy of the system) (9). Thus, a reduction in the capital energy investment could significantly improve the energetics of the system. Table 6.1 lists a breakdown of the capital energy subsidy required by systems 1 and 2. Recall that the energy embodied in the heliostats represents a mass-manufactured product. Not only does mass-manufacturing imply the replacement of human labor (a free energy resource) with automated machinery, but it 194 Table 6.1. Breakdown of the capital energy subsidy Of central receiver power stations (9) Per Cent of Total Capital Subsidya Components System 1 System 2 Heliostats 48.7 39.9 Receivers and Towers 21.3 9.3 Balance of Plant 21.7 34.7 Maintenance 8.3 16.1 a - Assuming a transportation distance of 1000 miles for delivery of prototype components and a system lifetime of thirty years. 195 implies the centralized manufacture of a product that must be transported to its end-use site as well. The 18.7 per cent of the energy embodied in the non-delivered heliostat (as produced at the manufacturing site) which originates from direct energy usage and required capital facilities {9), is assumed to be the energy cost of the use of mass-manufacturing techniques. Thus, mass- manufacturing techniques account for 10.7 and 10.5 per cent of the energies embodied in the installed heliostats of systems 1 and 2, respectively (9). Furthermore, 3.1 and 1.5 per cent of the energies embodied in the installed heliostats of systems 1 and 2, respectively, are required to deliver the heliostats as produced at the manufacturing site 1000 miles to the system site (compare that distance to the transportation distance for a heliostat manufactured in Michigan delivered to Arizona) (9). According to the above calculations, 6.7 and 4.8 per cent of the total capital energy subsidies of systems 1 and 2, respectively, originate from the mass-manufacturing of heliostats. Thus, the energy savings from utilizing decentralized, non-automated practices for heliostat fabrication instead of mass-manufacturing techniques will not significantly improve the energy characteristics of the system (for example, if decentralized practices reduce the energy consumed during mass-manufacturing by 75 per cent, the maximum possible reduction in the capital energy subsidy is 5 per cent). However, 67.5 per cent of the 196 energy required to install the components, and 23.4 per cent of the energy embodied in the general facilities originate from the direct energy usage and required capital facilities of automated construction practices (9). Thus, 42.8 and 47.9 per cent of the total capital energy subsidies of systems 1 and 2, respectively, originate from the use of automated construction practices (9). Obviously, the energy characteristics of a central receiver power station could be significantly improved by mini- mizing the direct energy and capital usage and maxi- mizing the use of human labor during the construction of the power station. It is clear that the energetics of central receiver power stations will not approach those of electricity pro- duced from fossil fuels. Central receiver power stations are low gain systems (approximately 1.6-3.3) (9) with high capital requirement factors (approximately 0.3-0.6) (9). As a result, even the central receiver power stations with the mOSt favorable energetics suffer from a severe growth limitation compared to their fossil fuel based counter- parts. A central receiver power station with a gain of 3.3, a capital requirement factor of 0.6 and a system life- time of thirty years has a maximum growth rate capability of 0.07. On the other hand, fossil fuel based electrical utilities have an energy gain of approximately 9 (1). From the energy analysis by Pilati (13), the capital requirement 197 factors of fossil fuel based power plants are approxi- mately 0.002 - 0.08. The maximum growth rate capability of a fossil fuel based power plant with an energy gain of 9, a capital requirement factor of 0.08 and a system lifetime of thirty years is 0.40. Even though central receiver power stations are not acceptable as independent energy supply systems, they can produce electricity, a valuable energy product, at an overall process efficiency of approximately 300 per cent (9) compared to an overall process efficiency of about 30 per cent (1) for the fossil fuel based electrical utilities. Thus, central receiver power stations can effectively reduce the consumption of fossil fuels for the large scale supply of electricity. Furthermore, since central receiver power stations are best suited to supply electricity for peak or intermediate load end uses, such systems are most effective in reducing the crude oil and natural gas, which are commonly consumed in the supply of peak and intermediate load electricity, consumed for the production of electricity. Unfortunately, central receiver power stations are practical only in areas of sufficient solar insolation such as the west and southwest portions of the United States. Production of industrial process heat from solar radiation Process heat for industrial usage as well as domestic hot water and hot air for space heating are energy 198 products produced specifically for consumption to provide some end-use service. Such energy products have no use as investment energies and, as a result, the concept of the growth capability of systems producing these energy products has little significance. Thus, any alternative system which produces process heat at an overall process efficiency greater than that of its fossil fuel based counterpart is a legitimate candidate for the reduction of fossil fuel consumption. The overall process efficiencies of the solar industrial process heat systems analyzed range from 106 to 363 per cent depending on the system and the utility requirement (reported as a per cent of the system's thermal output required as electrical input) (14). In general, a specific solar industrial process heat system will consume electricity at a constant rate while the system is opera- tional. The efficiency at which the collected heat (in the form of hot water, steam or hot air) is transported to the consumption site determines the length of the Operational periods of the system for a given energy demand. Thus, for a given output of the solar industrial process heat system, the utility requirement (in the form of electricity) will vary as a function of the thermal losses in the system. Since electricity is of a much higher quality compared to the output of the system, small increases in the thermal losses of the system can 199 significantly worsen the energy characteristics of the system. Thus, it is critical that the thermal losses in the system be minimized through proper design and installation. The utility requirement dominates the total energy subsidies of the solar industrial process heat systems analyzed, comprising 70.6, 59.7 and 53.2 per cent of the total energy subsidies of systems I, II and III, respectively (14). Thus, the use of mass-manufacturing techniques and automated construction practices do not represent a significant portion of the total energy subsidies of solar industrial process heat systems as is observed for central receiver power stations. For example, consider system III in which the non-delivered, non-installed solar collectors, the energy required to deliver the solar collectors 500 miles and the energy required for installation Of the components represent 15.9, 0.5 and 11.5 per cent, respectively, of the system's total energy subsidy (14). Thus, 11.2 per cent of the sys- tem's total energy subsidy originates from the use of mass- manufacturing techniques and automated construction practices (9, l4). Crop production Western (i.e., intensive) cultural practices of crOp production rely on the extensive use of products produced from crude oil and natural gas to obtain 200 maximum crop yields. Table 6.2 lists the breakdown of the energy subsidy for the production of corn and slash pine. The energy parameters of the production of dried and chipped crops are sensitive to the transportation distance of crop delivery and the moisture content of the crop (through both the drying energy subsidy and the transportation energy subsidy). These results indicate that the use of biomass as a solid fuel in a national energy supply role is far too energy intensive. Furthermore, the large processing energy requirements for the production of a solid fuel suggest that crops may be more efficiently utilized as a feedstock to an energy supply process (such as an alcohol plant) which consumes the crop at its moisture content as stored on the farm. Although the production of crops as a solid fuel for the supply of energy on a national basis is not energeti- cally attractive, the energy gain of crop production with minimal transportation distance of crop delivery is suf- ficiently high to allow the internal generation of required motor fuels, process heat, electricity and possibly some fertilizers without significantly reducing the crop out- put of the farm. For example, the internal supply of the transportation of crOp energy subsidy, the utility energy subsidy and one-half of the raw materials energy subsidy for the production of corn would reduce the crOp output 201 OHHm OCHOOOOOHQ OH EHOH EOHH >HO>HHOO QOHO Ho OOCOHmHQ I C mHWMQ #mg I .m e.O 0.0 O.H 0.0N O OO OOO O.N 0.0 0.0H O.N 0.00 v.OH OO 0.0 OO OCHm CmOHm 0.0 N.NN O.H O.vH H.OO OOO H.O 0.0 v.Ov O.N 0.00 N.NH OO ¢.O OH CHOU H338 ~61.”QO >333 H333 HOH 83m AmmHHE 2H8 at mod OOHOCm OOHOCM OOHOCM OOHOCm OOHOCm .HOHO>HHOO OOHOCM HCOHCOD OHHHHHD mHmHHOHmS HOHHQOO OCHmmOOOHm OQOO H0 980 MHCHOHQH 3mm CoHHOHHommCOHB Ho OOCOHOHD OOHmCCO OOHOCM HOHOE Ho HCOO HOm COHHOHHOQOCOHB III Ii. I, i I) II IiII [I Iii I'll I1! ..-lliu AOHO OCHQ CmmHm OCO CHOU Ho COHHOCOOHQ OCH Ho mOHOHmCCm OOHOCO HOHOH OCH HO C3OOCOOHC OCH UCO OCHOO OOHOCH .N.O OHCOB 202 by 6.7 and 23.7 per cent for a 50 and 500 mile trans- portation distance of crop delivery, respectively (15). The internal generation of a portion of the required energy subsidy could reduce the dependence of the crop industry on both crude oil and natural gas. Production of alcohol from corn The production of anhydrous (i.e., 199 proof) ethanol from crops with a high starch or carbohydrate content such as corn and sugar cane has received much attention in small private businesses partially due to the simplicity of the process. The technologies for the saccharification of starches, the fermentation of sugars to ethanol and the distillation of ethanol are well established and of a relatively low level. The establish- ment of a small alcohol plant does not require a great deal of capital and the government is providing funding for alcohol projects. The combination of these conditions make alcohol production attractive to small scale investors. Unfortunately, alcohol plants are inherently energetically marginal systems and are dangerously close to zero or even negative net energy producers. It is generally recognized that ethanol produced as a motor fuel should be used only in an interim energy supply role to conserve crude oil resources. Thus, the alcohol producing process need only have an overall process efficiency greater than that of a crude oil refinery, which has an overall process efficiency 203 of approximately 80 per cent (1), to be effective. Even though alcohol production is capable of Operating at an overall process efficiency greater than 100 per cent (16), the overall process efficiency of a non-optimally designed and operated alcohol plant may drop below 80 per cent, resulting in an increase rather than a decrease in the consumption of fossil fuels. Thus, it is critical that any alcohol plants implemented have the technical resources available to ensure optimal operation of the plant. Such technical resources are not readily available to a majority of the small scale investors pursuing the production of alcohol. As an energetically marginal system, it is desirable to identify those areas of energy consumption of an alcohol plant in which conservation will result in the greatest improvement in the energy parameters of the sys- tem. Table 6.3 lists the breakdown of the energy subsidy required for the production of alcohol from corn. The energetics of the alcohol producing system are sensitive to the distance the alcohol must be transported to its end-use site. In fact, the system cannot absorb the energy required to transport the alcohol (via truck) over 1000 miles (with the coal delivered 1000 miles) and still be a net energy producer (i.e., the energy gain of the system with a transportation distance of 1000 miles for delivery of the coal and alcohol is 1.01 (16)}. 204 Table 6.3. Breakdown of the energy subsidy required for the production of alcohol from corn (16) Per Cent of Total Energy Subsidya Energy .b .b .b SubSIdy 500 mi 1000 mi 1500 mi Capital 1.4 1.3 1.2 Raw Materials 1.3 1.2 1.1 Electricity and Fuel 25.1 23.1 21.3 CoalC 34.9 32.0 29.6 Feedstock (corn) 28.3 26.0 24.0 Transportation Energy for Delivery of Alcohol 8.9 16.4 22.7 a - Assuming solar radiation is the feed to the process b - Transportation distance of alcohol delivery (truck transportation) c - Delivered over a distance of 1000 miles via rail transportation 205 Furthermore, the total energy subsidy required for the production of alcohol is fairly well distributed between the electrical and fuel subsidy, the coal subsidy and the feedstock (corn) subsidy (and the energy required to deliver the alcohol at large transportation distances). Thus, incremental reductions in the individual energy subsidies cannot significantly improve the energetics of the system. However, the energetics of the system can be improved by significantly reducing the energy em- bodied in the process heat. The reduction of the energy embodied in the process heat consumed by the system could be accomplished by utilizing a solar industrial process heat system for the production of process heat, or by utilizing the waste heat rejected by an electrical utility. The latter alternative is known as the cogeneration con- cept. It is not clear which alternative to reducing the energy embodied in the process heat would be most effective in improving the energetics of the system due to the following argument: Even though there is no energy embodied in the waste heat of an electrical utility, the cogeneration concept implies the centralized production of alcohol requiring larger transportation distances for alcohol delivery. On the other hand, solar industrial process heat systems can be utilized by smaller, decentralized alcohol plants where the alcohol would be consumed locally. 206 Nuclear Energy Table 6.4 lists the breakdown of the energy subsidies of a 1000 MW(e) boiling water nuclear reactor (BWR) (0.3 per cent tails assays with and without fuel recycle from spent fuel rods) and a coal fired power plant and the energy gains of each system. Table 6.4 Breakdown of the energy subsidies of a 1000 MW(e) BWR (0.3 tails assays with and without fuel recycle) and a coal fired power plant and the energy gains of each system Per(33¢.offixmalIfimngyiaflxfidy Energy Enrichment or a Capital System Gain Mining Transportation (power plant) Others 1000 MW(e)b BWR (5) 6.0 16.0 68.0 16.0 --- 1000 MW(e)C BWR (5) 7.9 21.3 49.3 28.3 1.0 Coal Fired Power Plant (1) 9.7 25.0 52.0 20.5 2.5 a - Represents the percentage of the total energy subsidy required during uranium enrichment for the 1000 MW(e) BWR or the percentage of the total energy subsidy required to transport the mined coal to the power plant b - 0.3 per cent tails assays, no fuel recycle c - 0.3 per cent tails assays, recycle of uranium and plutonium from the spent fuel rods 207 The energy gain and the breakdown of the energy subsidy of a 1000 MW(e) BWR with 0.3 tails assays and recycle of uranium and plutonium from the spent fuel rods are very similar to those of a conventional coal fired power plant interchanging the coal transportation subsidy of the coal fired power plant with the uranium enrichment subsidy of the BWR. Thus, such a nuclear power plant is an acceptable candidate for the long-term supply of energy and is capable of completely displacing the consumption of fossil fuels for the production of electricity. Further- more, nuclear power plants have the capacity to reduce the consumption of fossil fuels for the production of electricity in the near future as well. Consider the overall process efficiency of a 1000 MW(e) BWR with 0.3 per cent tails assays and recycle of uranium and plutonium from the spent fuel rods. If the thermal energy equiva- lent of the energy which is released during the fission of the uranium is assumed to be the resource utilized by the system, the overall process efficiency of the 1000 MW(e) BWR is 34.1 per cent (5). However, uranium is not a useful energy resource to energy supply systems other than nuclear reactors. In this context, uranium may be envisioned as a freely available but limited energy resource. If the uran- ium is considered to be a free energy resource, the overall process efficiency of the 1000 MW(e) BWR becomes 789 per cent (5). Furthermore, the available uranium resource can be 208 considerably extended through the implementation of the breeder technology. However, as is observed for the central receiver power stations, the nuclear power plants have some end-use limitations in that, due to the long start-up and shut-down periods required for operation of the plant, they are not well suited for the supply of peak or intermediate load end-uses of electricity. Fossil Fuels The energy characteristics of systems supplying energy from fossil fuels are very similar regardless of the energy resource. For example, the production of electricity from crude oil, natural gas and coal all have an energy gain of approximately 10 (1). Furthermore, fossil fuel based systems all have low capital energy subsidies with the energy subsidy of the fossil fuel dominating the total energy subsidy of the energy supply system. However, there are subtle differences in the energy subsidies required to extract, process and deliver coal, crude oil and natural gas. In general, crude oil and natural gas are dis- covered and extracted during the same Operation and, therefore, have similar extraction energy subsidies. Nat- ural gas has a greater relative extraction energy due to its lower energy content and the required drying of the gas (i.e., removal of water and organic condensates) at the field site before it is transported. The energy 209 required to extract crude oil and natural gas once it is discovered is quite small. However, the total energy expended for the exploration and extraction of crude oil and natural gas yields energy gains of 56 and 45 (1), respectively. The easily accessible fields of crude oil and natural gas are rapidly being exhausted. The energy required to discover and extract crude oil and natural gas can be expected to increase significantly as the demand forces man to drill deeper into the earth, recover second and third generation yields from old wells, and develop more offshore drilling Operations. Domestically, crude Oil and natural gas are distributed via pipeline (a national average of 300 miles for crude Oil and 1000 miles for natural gas) which is the least energy intensive mode of fuel transportation (1). Imported foreign oil must be shipped by supertankers which reduces the energy gain of the distributed crude oil to approximately 35 (7). The energy gains of distributed domestic oil and natural gas are 51 and 24 (1), respectively (a more realistic gain for delivered crude oil is in the 30-35 range since the majority is imported). Conversely, the energy subsidy required to discover and extract coal is very small giving extracted coal an energy gain of 130 (1). However, the transportation of solids is extremely energy intensive. The delivery of coal a national average distance of 500 miles by rail, the 210 least energy intensive mode by which to transport solids (1), reduces the energy gain of distributed coal to 42 (1). Coal could be distributed via pipeline as a liquid-solid slurry. Transporting coal by pipeline could significantly enhance its energy characteristics. Second Level of Energy Analysis Implications Comments This level of energy analysis implications can be used to optimally match end uses with supply systems in developing future energy supply scenarios. However, in the presence of an energy crisis, the goal of alternative energy supply systems is not to supply energy as effici- ently as possible, but to displace the depleting resources. Currently, the United States is facing a crude oil supply crisis. At this phase of the crisis, the United States is suffering from the depletion of domestic crude oil supply, forcing her to import vast amounts of crude oil. The production of domestic crude oil, which was at its greatest level of 12 MM barrels/day in 1972, is projected to level off at 6-7 MM barrels/day by 1990 (4) including production from new discoveries and synthetic crudes. By the year 2000, the United States' crude oil consumption is expected to reach 20 MM barrels/day (4). The United States cannot develop a stable economy while relying on imported oil, the price of which cannot be controlled nor the supply guaranteed, to supply a large portion of her 211 energy demands. Furthermore, the foreign crude oil re- sources are finite as well. Thus, the United States must reduce the level of crude oil consumption to the level of domestic production and to ultimately completely displace the consumption of crude oil not only in order to achieve economic stability, but to avoid a similar crisis when the crude oil resources are depleted planet- wide. In order to reduce the consumption of crude oil to a level within the levels of domestic production, the United States must employ both conservation and alternative energy supply systems capable of reducing crude oil con- sumption while producing the energy products at the same rate for whatever crude oil based energy products feasible. A measure of an alternative energy supply system's capabil- ity to reduce the consumption of crude oil for the supply of a specific energy product is determined by comparing the overall process efficiencies of the alternative and crude oil based energy supply systems. The inverse of the overall process efficiency represents the total amount of primary energy that is embodied in the product of the system. Recall that the primary energy embodied in a product represents the fossil fuel equivalent (i.e., the summation of the crude oil, natural gas, coal and the fossil fuel equivalent of the hydro and nuclear derived electricity) of the energy resources embodied in that product. 212 It is possible to define the unit energy equiva- lence of an energy analysis to be some unit of crude oil, in which case the inverse of the overall process efficiency would represent the crude oil embodied in the products of the system. Defining the unit of energy equivalence in this manner is warranted only if the initial assessment of the nation's energy alternatives fail to identify alterna- tive energy supply systems capable of reducing crude oil consumption without increasing the consumption of other fossil fuels for the following reason. It is necessary to eventually construct a new network of energy supply systems to completely displace the need for fossil fuels. Furthermore, the technologies for such energy supply systems (such as the breeder reactor) are not sufficiently developed to allow the commercialization of these energy supply sys- tems. When the technologies are develOped to the stage of commercialization, a vast amount of energy will be required to invest in the construction of the new energy supply systems. The only available energy resource capable of supplying the required energy investment is coal. Thus, the wisest short-term energy policy is to conserve the coal reserves as much as possible by implementing alterna- tive energy supply systems capable of reducing crude oil consumption without increasing the consumption of coal. However, while conservation of coal is emphasized, the productivity Of the coal industry must be increased as 213 quickly as possible to ensure the availability of extracted coal when it is needed. Comparison of Alternative and Conventional Energy Supply Systems for the Supply of Specific End-Use Products Tables 6.5, 6.6 and 6.7 list the energy parameters of alternative and conventional systems supplying liquid fuels, electricity and heat (in the form of industrial process heat, domestic hot water and space heating), respectively. All values which appear in Tables 6.5, 6.6 and 6.7 are either the results of analyses performed by the author (documented in the Appendices of the report and summarized in Chapter 4) or documented in the litera- ture survey of Chapter 5. The parameters and system descrip- tions listed in Tables 6.5, 6.6 and 6.7 serve as the basis for the values and systems listed in Tables 6.8, 6.9 and 6.10. Discussion of the Provision of Transportation Services In 1979, 10 MM barrels/day of the 18 MM barrels/day of crude oil consumed in the United States provided liquid fuels for transportion (4). The potential exists for a tremendous reduction in the consumption of crude oil to provide transportation fuels by increasing the efficiency at which the thermal energy content of the fuel is converted to the transportation service. For example, it is estimated that the consumption of crude oil for transportation can be 214 HOCOOHO HOH OOCOHme COHHCCHHHme OHHE OOO pCO AHOOC mmOOOHQ HOH pOmCO HOOD HOH OOCOHme >HO>HHOp OHHE OOO .CHOO ECHO HOCOOHO HOOHQ OOH mo COHHOCOOHO I m OH0.0 III OO.HHH HH.H HOV OCHOO ECHO HOCOOHO III OO.H O0.00 0.0 HHV OHOCm HHO EOHH OCHHOOOO III OO.H O0.00 0.0 HHV HmoO EOHH OCHHOOOU III HH.H OO.NO 0.0H HHV HHO OpCHO EOHH OCHHOOOO HOHOOO HOHOOC HOV CHOU EOHmhm HCOEOHHCUOm COHHONHHHHD OOCOHOHHHm OOHOCm HOHHQOU OOHCOmOm OOOOOHO HHOHO>O .1 ..II lilyl'. ‘. 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I." OOCCHHCOU .O.O OHCOB 219 reduced to 4.5 MM barrels/day by the year 2000 as a result of increasing the average car mileage to 36.5 mpg (4). However, the consumption of 4.5 MM barrels/day of crude oil is itself a sizable quantity of energy representing approximately 70 per cent of the estimated domestic produc- tion of crude oil. The alternative resources to the production of liquid fuels are coal, oil shale and biomass. The production of liquid fuels from biomass could only supply a small portion (i.e., less than 20 per cent based on the displacement of 1 MM barrel/day of crude oil, which is ten per cent of the current consumption of crude oil for transportation) of the liquid fuel demand leaving the burden of liquid fuel supply on the non-renewable resources of coal and oil shale. The lack of attractive alternative liquid fuel producing systems suggests the examination of an alternative transportation system based on electrical energy. From the overall process efficiencies listed in Tables 6.5 and 6.6, the primary energies embodied in both liquid fuels and electricity can be estimated. However, the desired parameter is the energy required to provide the transportation service. Thus, the inverse of the overall process efficiency is divided by the efficiency at which the energy product is converted into the desired end use, resulting in a parameter representing a relative measure of the energy required for transportation services. Table 6.8 lists the end use 220 Table 6.8. Comparison of the relative primary energy consumed per unit of tranSportation work provided by various energy supply systems Relative Primary End-Use Overall Energy Consumed Per Conversion Process Unit Transportation System Efficiency Efficiency Work Provided Gasoline from a Crude Oil 0.5 0.826 2.42 Gasoline from a Coal 0.5 0.607 3.28 Gasoline from a Oil Shale 0.5 0.578 3.47 Alcohol from a Corn 0.5 1.110 1.80 Electricity from Crude Oil 0.9 0.279 3.98 Electricity from Coal 0.9 0.288 3.86 Electricity from Natural Gas 0.9 0.262 4.24 Electricity from Liquefied Coal 0.9 0.182 6.09 Electricity from Gasified Coal 0.9 0.190 5.85 Electricity from Oil Shale Crude 0.9 0.193 5.75 Central Receiver Power Station 0.9 3.32 0.33 Nuclear Energy 0.9 0.341 (7.89)C 3.26 (0.14)C a - End-use conversion efficiency of 0.5 is intended to reflect the increase in car mileage b - Values are defined as: l . 1 Overall Process Efficiency End:use Conversion c - See Table 6.6 EffiCiency 221 conversion efficiencies and the relative measure of the energy required for transportation of alternative and conventional transportation energy supply systems. Note that the use of the end-use conversion efficiency assumes that the energies embodied in the various conversion facilities are similar. Also, note that systems producing electricity from wind energy and the use of photovoltaic cells are not included in Table 6.8 because the systems represented by the parameters listed in Table 6.6 are not suitable for the production of electricity as a transporta- tion fuel. The complete provision of transportation services using liquid fuels from coal, oil shale and a small portion from biomass will consume the domestic coal and oil shale reserves at an extremely fast rate. On the other hand, the use of electricity from central receiver power stations or nuclear reactors as a transportation fuel can reduce the consumption of crude oil for the production of transportation fuels up to 94 per cent without increasing the consumption of other fossil fuels. Electricity A power plant is generally classified according to the end use of, or the demand cycle satisfied by, the elec- tricity produced. The end uses of electricity are classified as either the supply of peak, intermediate or base load electricity. Base load power plants generate a constant supply of electricity while intermediate and peak load power 222 plants generate enough electricity to meet the fluctuating demand above the base load supply. A power plant capable of supplying all end uses of electricity is characterized by short start-up and shut-down time requirements and produces electricity from an energy resource which is continuously available. Fossil fuel based power plants are suitable for the supply of all end uses of electricity. However, the alternative electricity supply systems are not. Table 6.9 lists the embodied energy and the end uses of the electricity produced by conventional and alternative electricity supply systems. Of the alternative energy supply systems, the electricity with the least embodied primary energy is pro- duced from nuclear power plants (excluding electricity from wind energy). Furthermore, nuclear energy has the fewest location limitations. At the present rate of consumption of U235 for the production of light water nuclear reactor fuel, domestic U235 resources are estimated to last 40 to 60 years (17). However, a by-product of the production of light water nuclear fuel is 0238, the feedstock of the 238 is stock- breeder nuclear reactor. In fact, sufficient U piled at the Oak Ridge enrichment plant to operate 400 1000 MW(e) breeder power plants for a period of 500 years (17). Thus, the reduction of the consumption of fossil fuels for the production of electricity by the implementation of light water nuclear reactors is not only the largest 223 Table 6.9. Embodied energies and end-uses of electricity produced by various systems Primary Energy Embodied in System End-Usea the Electricity Crude Oil Power Plant b,i,p 3.58 Coal Power Plant b,i,p 3.47 Natural Gas Power Plant b,i,p 3.81 Gasified Coal Power Plant b,i,p 5.27 Liquefied Coal Power Plant b,i,p 5.49 Oil Shale Power Plant b,i,p 5.17 Nuclear Power Plant b 2.43 (0.13)c Central Receiver Power Station i,p 0.31 Wind p 0.03 Photovoltaics p 0.51 a - b 3 base load; i E intermediate load; p 5 peak load b - Values are the inverse of the overall process efficiency of the system c — See Table 6.6 224 scale and the least location restricted alternative to electricity production, but the depletion of domestic U235 resources in the production of light water reactor fuel will produce enough U238 to allow the fabrication of sufficient breeder reactor fuel to supply the United States' energy consumption for thousands of years (17). Unfortunately, the feasibility of electricity production from nuclear light water reactors at a smaller scale such as 50 MW(e) or less has not been demonstrated. In applicable regions of the United States, solar energy based alternatives are effective in reducing fossil fuel consumption for the smaller scale production of electricity. The repowering of existing fossil fuel based power plants with steam produced using the central receiver (i.e., power tower) concept could become a very effective method for the reduction of crude oil consumption for the production of electricity in the west and southwest regions of the United States. However, the operation of fossil fuel (primarily coal) based power plants will be required for the small scale production of electricity for a major portion of the nation. Heat Currently, the process heat consumed by the indus- trial sector and heat consumed for the supply of hot water and space heating by the residential sector are produced primarily by the direct combustion of natural gas and, to 225 a lesser extent, by the combustion of fuel oil and the conversion of electricity. As mentioned in the discussion of solar process heat systems, heat is an energy product suitable for end-use consumption only, and is not con- sidered an energy form suitable for investment end uses. Thus, the dynamic behavior of a heat supplying system is not an important consideration. The important character- istic of a heat supplying system is the total primary energy embodied in the end-use energy form (i.e., such as steam, hot water or hot air). The heat supply systems described in Table 6.8 represent the supply of available thermal energy and not the end-use product itself (with the exception of the solar heat supply systems). Thus, the use of an end-use conversion efficiency is required to compare various heat supply systems according to the production of specific energy products. Table 6.10 lists the primary energy embodied in heat for the supply of industrial process heat, domestic hot water and space heating produced by various supply systems. The potential exists for the significant reduction of fossil fuel consumption for the supply of heat through the use of solar process heat, space heating and domestic hot water supply systems. Solar heat supply systems can be installed at the site of consumption, which guarantees a supply of energy to the consuming system. However, such systems cannot practically supply the entire heat demand of 226 mm.o = 08.0 vs.m c.m.m ommmeoflm oxmfi.ov mo.m coflnofluummu 0: mm.o nammgc Ham.o m.m.m msmumcm umeosz Eoum wpwofluuomam mwumum pmpflco om.o ummz .pmmznhSOm mm.o mm.m 6.m.m beefiumpm umzom Hm>fimomm Hmnusmo Eonm mufiOAHuomHm ma.o hcmEumc umwz OO.H nv.m ©.m.m mmumcm Hmaom mv.o xflcmonm oo.H mm.~ 6 assumcm umaom mmpmum cmuflc: mm.o ummB .vmm3np90m OO.H mo.m m mmumcm Hmaom am.m = mm.o oma.o n.m.m cameo HmAMflmmo Eoum mpflofluuomam mo.v = mm.o mom.o o.m.m mmo Hmnsumz EOWM >#H0flnuomam mm.m = mm.o mmm.o 6.m.a cameo Eoum mgfiofiuuomam ss.m = mm.o msm.o 6.m.m maflo mosuo Scum wuflowuuomam Gm.H = mm.o HO0.0 w.m.m Hmoo omflmqmmo Nv.a = mm.o mmm.o o.m.m 6 mac amusumz HR.H = oo.o ssm.o o.m.m a cameo ms.H cofluoflunmmu 0: oo.o 4mm.o c.m.m mane mango “oopoum hmuwcm coflpmooq Mocmfloflmmm moswfloflmmm mmD OOHDOmmm Q CH UmHUOQEm coflmuw>coo mmmooum ovum wmuwcm wmnwcm mumaflnm mmD 6cm Hamum>o meumxm waaosm mooHum> mo muospoum pawn mcu ca pmfiponfim mmumcm mumeflum .oa.m OHQMB 227 mmfluflaflomm coflmum>coo mmSIpco msu wpDHUCH no: mmOU paw Hmsm M MD muw>flamp cam coflwodpoum mucwmmummu Emummm p m.m magma mom 0 xocmHOHmwm coflmnm>coo wmonpcm moccaoflmmm mmmooum Hamum>o H . H "m3oHH0m mm pmumHDono mum mmsHm> n @CAumms woman m m umumz won oflummEOU m p pom: mmmoonm m a m meCfiucoo .oa.m mHQMB 228 the existing system due to thermal storage requirements. Furthermore, they suffer from locations restricted to the west and southwest regions of the United States. Electric- ity from central receiver power stations suffer from similar limitations. The combustion of biomass to produce process heat has no location or demand limitations, but the produc- tion of biomass cannot absorb large transportation require- ments without a dramatic increase in the energy embodied in the heat produced. Thus, the use of biomass to supply heat is limited to relatively small areas with regard to the production site and the end-use site. Electricity from nuclear energy can effectively reduce the consumption of fossil fuels for the supply of heat without location or demand limitations. However, an increase in the supply of energy from nuclear power stations cannot be expected for at least 10 to 15 years from now. The combination of the above observations indicate the unavoidable use of coal for the supply of heat as the supply of natural gas and fuel oil begin to decline. The direct combustion of coal poses environmental problems and requires a large expenditure of energy for transportation, especially if used for the small-scale, decentralized supply of heat. Thus, the use of gasified coal appears to be the most viable alternative to the deplet- ing resources of natural gas and fuel oil. 229 Third Level of Energy Analysis Implications General Characteristics of a Future Energy Supply Scenario: Transition into a New Era It is clear that the crude oil supply crisis now facing the United States is just the beginning of the decline of the fossil fuel energy supply era. However, the political and industrial sectors of this country are looking upon the vast domestic coal reserves as the solution to the crude oil supply crisis and not beyond the consumption of the vast, but indeed finite, coal reserves. The most es- sential feature of the energy policy adopted for this nation is the guarantee of the availability of adequate energy resources to allow the construction and implementation of the energy supply system or network of energy supply systems that will displace the need for fossil fuels. Furthermore, this energy supply system must have a sufficiently high energy gain with regard to the capital requirement factor in order to have the capacity to support a healthy industrial and, thus, economic growth. At the present stage of techno- logical development, the only acceptable long-term energy supply system candidate is the breeder nuclear power plant. Even the breeder technology is a long way from commercial- ization due to safety design problems with regard to both operation of the plant and disposal of waste products (17). In addition to the technical problems associated with the breeder concept, enough public concern and political 230 pressures exist to have caused President Carter to cancel the plans to construct the first breeder reactor in the United States (17). In short, the technology to displace the need for fossil fuels does not presently exist and will probably not become available for at least another 20 to 30 years. In 1979, the United States consumed 37 quads of crude oil, 20 quads of natural gas, 15 quads of coal, 2.75 quads of nuclear power and less than 1 quad of hydroelectric power and other energy resources (18). During the period from 1820 to 1979, the United States has consumed approxi- mately 1095 quads of coal, leaving 3905 quads of the esti- mated 5000 quads of domestic recoverable coal reserves (22). Liquid fuels and synthetic pipeline gas can be produced from coal at energy gains of 6.7 and 25.8, respectively, with resource utilization factors of 1.49 and 1.63, respec- tively (1). Thus, the displacement of 37 quads of liquid fuels and 20 quads of natural gas will require the pro- duction of 94 quads of coal (assuming the energy subsidies required for the production of liquid fuels and synthetic gas must originate from coal as well). Note that the initial capital investment energy is neglected due to the small capital requirement factor of the systems (i.e., less that 0.01 (3)}. Assume that coal will displace crude oil and natural gas by the year 2010. This would require a coal production growth of 6.4 per cent annually and would 231 leave 2436 quads of the recoverable domestic reserves non- extracted. If the total domestic demand for energy did not increase above the 1979 consumption level, the coal reserves would be able to meet the demand for only 22 years beyond the year 2010, or a total of 53 years from the year 1979. Furthermore, consider the energy that would be required to construct an energy supply system, based on the breeder nuclear reactor, capable of producing a net energy of 78 quads, the total United States' consumption in 1979 (18). The energy gain and capital requirement factor of a pressurized water reactor with 0.3 per cent tails assays and no recycle of fuel are 4.09 and 0.036, respectively (5). Assume the breeder reactor doubles the capital requirement factor and reduces the remaining energy subsidy by 80 per cent {due to a 98.6 per cent reduction in volume of fuel required (17)}. The energy gain and the capital requirement factor of the breeder power plant would be 8.8 and 0.072, respectively. An energy production rate of 86.9 quads per year would be required of the breeder energy supply system and 188 quads of coal would be required to construct the initial supply system (i.e., energy required for replacement of depreciated plants would be supplied by the breeder system itself) based on a system lifetime of 30 years. Thus, 8 per cent of the coal reserves remaining after the displacement of crude oil and natural gas with coal would be required to construct the breeder energy supply system. 232 The above calculations indicate that ample reserves presently exist to make the transition from fossil fuels to a long-term energy supply system. It is also clear that the United States faces an era of mandatory energy conserva- tion if the industries are to grow (which is essential to a stable American economy) without increasing energy consump- tion. However, even if a zero energy consumption growth rate can be achieved, if coal is utilized to displace the depleting crude oil and natural gas resources, the time frame in which the long-term energy supply system must be developed and implemented is simply not adequate. Obviously, the most competent and responsible short-term energy policy (based on the presently available information) is based on the reduction of crude oil and natural gas consumption with an emphasis on the conservation of the domestic coal re- serves. In other words, the United States must extend the life of its domestic crude oil and natural gas reserves with- out the extensive utilization of domestic coal and prefer- ably without a dependence on foreign crude oil. This goal is obtainable through the implementation of short-term, high overall process efficiency alternative energy supply systems such as central receiver power stations, light water nuclear reactors, solar process and domestic heat, biomass, wind energy, ocean thermal energy, etc., which can signifi- cantly increase the effective efficiency of crude oil and natural gas consumption, and the implementation of mandatory 233 energy conservation practices emphasizing human labor instead of automation and decentralized manufacturing to reduce transportation requirements. These measures Qxxld be accompanied by the rapid expansion of coal production and the construction of facilities for the production of gaseous and liquid fuels from coal for the following reasons. The fabrication of building materials such as steel and concrete required for the construction of an energy supply system as well as the construction itself are highly energy intensive processes requiring electricity and liquid and gaseous fuels. The capability to produce these energy products from coal must exist in the event that crude oil and natural gas resources are depleted prior to the construction of a long-term energy supply.system. Dynamic Energy Analysis Presently, the most important application of a dynamic energy analysis is the modeling of a transition era in which the net work of current energy supply systems changes through the implementation of alternative energy supply systems over a period of time. The change in the network of energy supply systems must be implemented utilizing the fixed fossil fuel resources. However, once an alternative energy supply system is producing energy, any of the system's energy outputs not consumed may be utilized as operational or capital energy subsidies for any other energy supply system. The structure of the 234 energy supply model is illustrated in Figure 6.1. The definitions of the model parameters are listed in Table 6.11. To use the model, an initial network of energy supply systems (i.e., mm(to,n)}, an initial available energy {i.e., e (to)} and the desired growth accumulation rate of all N energy supply systems are set. Note that in order to use a conventional growth rate, all systems must be initially present in some quantity. Also note that the energy resources are either fixed in magnitude and the rate of consumption is not limited (i.e., fossil and nuclear fuels) or the resource is renewable and the rate of consumption is limited (solar energies). The (t.). model has three independent varlables’econsumption 1 (t.). Two variables are set and g(n) and eaccumulation l the other is calculated according to the constitutive relations and energy balances listed in Table 6.12 and Table 6.13., respectively. 235 Table 6.11. Definition of energy supply model parameters Parameter n ti(i=0,l,2...) tC(n) tl(n) m(ti,n) mm(ti,n) mr(ti,n) e (n) c Definition The nth energy supply system of N total energy supply systems. The energy subsidies and the energy output of each unit of the nth energy supply system are fixed and specified. The specific year in the time span being evaluated. The period required for the construction of a unit of the nth energy supply system. The operational lifetime of a unit of of the nth energy supply system. The number of units of the nth energy supply system for which construction is begun at time ti' The number of mature units of the nth energy supply system at time ti, requiring Operational energy and producing an energy output. The number of replacement units required for the nth energy supply system at time ti requiring capital energy investment. The total capital energy subsidy of a unit of the nth energy supply system amortized over the construction period tc(n). ec(n) is the required input of m(ti,n) and mr(ti,n). Table 6.11. 236 Continued Parameter eop(n) er(k,n) (n) out q(n) q(n) econsumption (t i) Definition The annual Operational energy subsidy of a unit of the nth energy supply system. eop(n) is the required input of mm(ti,n). The specific (i.e., the kth) annual energy resource required by a unit of the nth energy supply system. The annual energy output of a unit of the nth energy supply system. Qualifier of the energy output of the nth energy supply system. q(n) indicates the appropriate consumption rate of the output of the nth energy supply system (i.e., a total energy consumption is specified for each year of the time span being evaluated and the consumption of the output of each system is specified as a portion of the total energy consumption according to q(n)}. However, any produced energy that is not consumed is delegated to an available energy reserve regardless of its qualifier. The growth rate of the nth energy supply system.§fln) is constant for each evaluation of the energy supply model. The total energy consumption for the year ti' 237 Table 6.11. Continued Parameter Definition e (t.) The annual summation of all produced excess 1 energies that are not consumed. e (t-) The annual energy required for Operational recycle 1 energy and investment energy. e . (t.) The summation from time t to t. of accumulation 1 o 1 (ti) o e (ti) - e excess recycle 238 :0 cH MH . 3.032. o H H22:.O+HT. H Hmsvm+HmJ Avu+Avu u. ACVHIACVHIJ 2.3“...“ E} M an A guy + EH» 1 210qu . EVE . $.1ch + S Tongue E ASH“ v Hp “ om 3.03:5 . Huficm n IA. 0 . s so 3 U. A U. . a 35. Eur .. $2ch + S O H 0 Ev 0. v .p x E. as: liliuc.1'|llllll'll. .lvt'lu All '(ll-.ll"(\')‘..|‘|!l‘.l|t|lllnll| I I‘IIII‘IIF HOOOE >Hmmsm >mumcw OHEmc%© How menchHumeu m>HusuHumcou Bass 5 Base: 3 .NH.m OHQMB 239 mmevan mHozomHm I AHuv m H AHpv coHuMHDEDOOM Anne 8 Amy HHS filcvaom . lc.fluces + Assam . 11:.flpcna + 1:.q025mg N u lgnvmaosomum inc 2 HUG Hug Avammooxmw + Hficvq . AHDVCOHDQESmOOOOH w n Hfisvusom . HO.HDVEEV w z z :3 HOOOE >Hmmsm hmumcw OHEmcmp MOM mmocmHmn mmumsm .MH.o OHQMB 240 a wHomomH T”: w >mhmcw mHoxomH a mmwoxm 73 m >mumcm mmmoxm Acvq . AHHVCOHHQEDmCOOO uospoum xmuwcm mo mawu Op mchuooom coHuQEDmcoo >mhmsm O a a luv 8 . 11a..uvue + is..ucec >muwcm ucmEpmm>CH lccaom . lc.flncae >muwcw HmcoHumummo u a 12.xi m . is..pcse mousommu mmumcw H.O wusme Op wmx 241 Homo: >Hmmsm zmnwcm .H.o wusmHm mmOHSOmmH wwumcw mHOSM HmmHosc OGH3 p 0 AH“: SUMHQESOMO mawummm mHQmsm o wmumcm xmnmcm maanHm>m mo xuozumc a mmmEOHn HMEHmnu MMHOm H _ mHOSM HHmm0m 242 The model may be Operated by yearly increments calculating either e (t-) consumption 1 accumulation(ti) or e by setting the growth rates and one of the other two independent variables and using the constitutive relation- ships and the energy balances. The desired behavior of the transition of the energy supply network is the maximum lifetime of fossil fuel resources (even at the expense of U235 (t.) depletion) With a suffiCient eaccumulation l to allow construction of the long-term energy supply system at an annual total energy consumption capable of sustaining the United States at an acceptable standard of living. The most effective transition can be found via trial and error. However, it should be possible to incorporate the described structure of the energy supply model into an existing systems management routine which translates the structure into a differential form and allows the injection of systematic policy adjustments until the desired goal is met. Such an effort is currently underway utilizing the systems management routine described by Forrester (19). Recommendations for Further Efforts in Energy AnalySis Comments The science of energy analysis lacks research efforts in its development, application and interpretation. The necessary research efforts in each area are discussed below. 243 Development Currently, energy analysis relies on input- output theory to estimate the embodied energies of materials and energy products based on dollar interactions between the sectors of the economy. This interaction needs to be defined in terms of the physical flows of materials and energy rather than dollar flows to eliminate the large degree of uncertainty in the resulting energy intensity coefficients. Application In order to develop a competent energy policy, the energy parameters of all energy supply systems must be precisely and accurately defined. This requires not only the application of energy analysis to all configura- tions of the energy supply systems currently in existence, but to every prOposed alternative energy supply system as well. Energy analysis needs to be institutionalized in the same manner as economic analysis, such that both tools are utilized in the development and evaluation of energy supply systems. Furthermore, the concepts of energy analysis should become a part of the educational process in the same manner as economic analysis, such that the parameters of energy analysis are as widely recognized and understood as those of economic analysis. The application of energy analysis to energy supply systems is the most urgent task of the development of a 244 national energy policy. The energy parameters listed in this report are by and large based on isolated analyses and have no confirmation or an acceptable level of confidence. These parameters must be accurately known in order to develop an energy policy program. Interpretation The ultimate consequences of any proposed energy policy can only be predicted through a dynamic energy supply and demand model. Thus, an acceptable model and the analysis of that model must be developed and tested, followed by the evaluation of proposed energy policies based on the energy parameters of the systems utilized in those policies. APPENDIX A APPENDIX A ENERGY ANALYSIS OF CENTRAL RECEIVER SOLAR THERMAL POWER STATIONS General Approach The capital required to construct, and the utilities and raw materials required to operate a proposed large scale energy supply system that is presently at the pilot plant or small scale stage of development, are based on Operational data of the pilot plant or small scale system and theoreti- cal calculations. The large degree of uncertainty that exists in the estflmmed capital, raw materials and utility require- ments is propogated to an energy analysis based on those requirements. Thus, comparison between such proposed large scale energy supply systems and conventional energy supply systems based on the absolute values representing the results of the energy analyses is questionable. However, energy analysis can be used to screen various designs of a proposed alternative energy supply system in order to identify those designs with the best energy characteristics. Alternative energy supply systems often require the fabrication of components that are at the prototype stage of development. Such prototype components are not products of the established industries included in the economic 245 246 structure of the United States (8). Thus, process analysis must be used to estimate the energy embodied in these components. The rigorous extension of process analysis to prototype components requires the estimation of utility, raw material and capital requirements of a conceptual manufacturing process. Such studies generally do not exist. Furthermore, if such a study is found, it is most often too incomplete to serve as the basis for an extension of process analysis. A Central Receiver Solar Thermal Power Station (abbreviated as CRSTPS) is a proposed large scale energy supply system presently at the pilot plant stage of develop- ment and requires the fabrication of components (i.e., heliostats, receivers and towers) that are at the prototype stage of develOpment. For convenience, the energy analysis of the CRSTPS is divided into two phases, estimation of the energy embodied in the prototype components and the energy analysis of the system itself. Data describing an envisioned process for the manufacture of heliostats, receivers and towers are not available. Information obtained from the disaggregation of energy intensity coefficients is used to extrapolate manufacturing data from established industries (considered to utilize manufacturing techniques similar to those envisioned for the manufacture of the prototype components) and allow the extension of process analysis. The operation of a CRSTPS is similar to a conven- tional power station in that steam is produced to drive a 247 turbogenerator that generates electricity. In order to collect enough solar radiation (as heat) to produce steam of a sufficient quality to drive conventional turbogenera- tors, concentration ratios similar to parabolic dish con- centrating solar collectors are required. A field Of helio— stats focused on a single receiver are utilized to approxi- mate the reflective surface of an enormous parabolic dish. The total reflective surface area required to supply heat for the Operation of a power station is a function of the efficiency of the heliostat field for the production of electricity for a specific end use (i.e., peak, intermediate or base load electricity). The solar radiation collection subsystem of the CRSTPS (including the heliostats, receivers and towers) comprisesa large fraction of the total capital investment of the system. The design of the total solar radiation collection subsystem is strongly influenced by the design of the heliostats and the layout of the heliostat fields, which also determine the efficiency of the collector field. This is the area in which the major variations in system designs of a CRSTPS are found. A trade-off occurs in capital cost reduction by either maximizing the efficiency of the collector field, thus minimizing the total reflective surface area required, or by minimizing the cost of the components of the collector field, which lowers the efficiency of the collector field and increases the total reflective surface area required. 248 The high efficiency collector field requires the heliostat to have low Optical losses (i.e., a high quality reflective surface) and optimal focusing properties. The better the focusing properties, the smaller the area and depth (referred to as the focal point region) of the image produced by the field are. Furthermore, the smaller the reflective surface area per receiver, the smaller the focal point region. The efficiency of the receiver is influenced by its ability to contact the entire image at the focal point on an absorbing surface with minimal reflective losses. The image, which in reality defines a region rather than a point, is most efficiently absorbed by a cavity receiver. However, if the image becomes too large, the size of a suit- able cavity receiver would be impractical forcing the use of an Open absorber receiver. The efficiency of a reflective surface decreases as the angle between the incident solar radiation and the normal to the reflective surface increases (referred to as cosine losses). Cosine losses can be mini— mized by positioning the field only in one quadrant of the area surrounding the receiver requiring smaller heliostat fields. Thus, the high efficiency collector field approach to system design utilizes a high quality reflective surface (including Optical and focusing prOperties) and optimal reflective surface area to receiver ratio to allow prOper field geometry and positioning along with the use of cavity receivers. The lower efficiency collector field uses a lower 249 quality reflective surface and fewer receivers and towers (and perhaps open absorber receivers). Two system designs are analyzed that reflect the two approaches to collector field design. The high effici- ency collector field system is described in a design evaluation (design report 1) performed by Martin Marietta (l) and the lower efficiency collector field system is described in a design evaluation (design report 2) per- formed by the Mitre Corporation (2). Description of Data Comments The data required for both phases of energy analysis (i.e., estimation of the energy embodied in the prototype components and the analysis of the entire system) are taken from the design report describing the system under analysis. High Efficiency Collector System The data describing the system based on the high efficiency collector system are contained in a system evaluation performed by the Martin Marietta Corporation (1) (i.e., design report 1). The data describing the prototype components are presented as the conventional components required to manufacture the prototype components in terms of 1977 dollars. The remaining components required by the system are also presented in terms of 1977 dollars. 250 The general facilities (i.e., buildings, roads, etc.) are reported as a single subcontracted item in terms of the purchaser's price in 1977 dollars. This dollar value represents all energies embodied in the general facilities including transportation requirements, equip- ment, direct energy usage and required raw materials. The dollar values reported for the components of the system represent the energy embodied in the delivered component only. The energy required for the installation of com- ponents (other than the general facilities) is estimated from information available from the disaggregation of energy intensity coefficients. The raw materials required for the Operation of the system (not to be confused with the raw materials required to construct the system) are either negligible or they are included in the maintenance allowance of the system (excluding the thermal storage materials). The thermal storage materials required during the lifetime of the system are reported in terms of separate costs for the non- delivered materials (i.e., the producer's cost) and the delivery requirement in 1977 dollars. The maintenance allowance is reported as an annual expenditure that is assumed to represent the purchaser's cost for maintenance services (similar to the subcontracted cost for the general facilities) in 1977 dollars. The utility requirement of the system is reported as a percentage of the system's electrical output that is fed back to the system. 251 Lower Efficiency Collector System The data describing the system based on the lower efficiency collector system are contained in a system evalu- ation performed by the Mitre Corporation (2) (i.e., design report 2). The data describing the prototype components are presented as the purchaser's cost of materials required to manufacture the prototype components in 1976 dollars. The remaining system components are presented as the purchas- er's cost Of the components in 1976 dollars. The data describing the general facilities and the maintenance requirements are presented in the same manner as indicated in design report 1, in 1976 dollars. The energy required for the installation of components is estimated from informa- tion available from the disaggregation of energy intensity coefficients. There are no reported raw material require- ments (i.e., raw materials not included in the maintenance allowance) or utility requirements. Determination of Energy Embodied in Prototype Components General Approach for Extension of Process Analysis to Prototype Component Manufacturing Systems The only data available are the producer's prices of components or materials required to manufacture the helio- stats, receivers and towers (i.e., the raw material require- ments). The purchaser's prices are modified to producer's prices that are converted to embodied energies. The remain- ing energy inputs of utilities (direct energy usage) and energy requirements for capital facilities, services, trade 252 and transportation are estimated from the energy embodied in the non-delivered raw materials using information obtained from the disaggregation of the energy intensity coefficient of a similar (referred to as an analogous) industry that is one of the 357 producing economic sec- tors (8). This procedure allows the estimation of the energy embodied in a non-delivered product. The delivery of the prototype component to the system site is assumed to be accomplished by truck transportation {requiring 7,000 Btu primary/ton-mile (4)}. The distance of delivery is varied in order to evaluate the sensitivity of the energy parameters to the transportation requirements. The analogous industries assumed for the manufacture of the prototype components are listed in Table A.1. Table A.1. Analogies between manufacture of prototype components and established industries Prototype Analogous I-O Component Industry Sector Heliostat Auto Industry 5903 Receiver Boiler ShOps 4006 Tower New Construction 1103 Note that the analogy between heliostat manufacture and the auto industry is made to incorporate the mass manufacturing energy intensity into the heliostat. The Department of Energy is considering mass manufacturing techniques as tools for cost reduction in the production of heliostats. 253 Definition of Nameplate Processing Systems Responsible fin:thelmefiaCUmxaofIhrtofinxaCbmpmuxfis The extension of process analysis to the manufacture of the prototype components includes the system that fabri- cates the component and the system that delivers the com- ponent. The definition of the nameplate processing systems responsible for the manufacture and delivery of the proto- type components are shown in Figure A.1. raw 'non- delivered materials ' component delivery _W b truck component manufacture component boundary of nameplate : processing 2 system m u vi 0 m a +’>1 m c) p :»c Otmm +J-H a) H twa msaciwa > x: 0 34m HGJQ CL n m cm or: -Hs:m cu m :4 m :z: wan): c: m 4) g aim H 4) Figure A.1. Definition of nameplate processing system for manufacture of prototype component 254 Application of Process Analysis to the Prototype Component Manufacturing Systems Comments Process analysis is used to determine the raw material requirements for fabrication of the prototype components and the energy required for component delivery. Heliostats Raw material requirements Tables A.2 and A.3 list the raw material require- ments for fabrication of the 23,310 heliostats described in design report 1 and one heliostat described in design report 2, respectively. Delivery requirements Perry, et al., (4) report private, inter-city truck transportation to require 7000 Btu primary energy per ton-mile of work. The mass manufactured and delivered portions of the 23,310 heliostats described in design report 1 (i.e., the mirror assembly and the support structure) and the 22,500 heliostats described in design report 2 (excluding concrete, sand and the cone and assuming that the tracking and drive mechanism of each heliostat weighs 500 lbs.) are 60,650 tons (l) and 29,273 tons (2), respec- tively. Table A.4 lists the transportation energy require- ments as a function of the transportation distance for the delivery of the heliostats. 255 Table A.2. Raw materials required for fabrication of the 23,310 heliostats described in design report 1 (l) Purchaser's Price I-O Component (x 106 $1977) Sector Mirror 9.010 3501 Mirror Assembly 35.400 4004 Heliostat Support Structure 30.800 4004 Azimuth Drive Assembly 19.300 4905 Elevation Drive Assembly 16.920 4905 Motors 4.640 5304 Position and Limit Indicators 5.740 5305 Power Distribution Equipment from Electric Plant 1.940 5308 Calibration Equipment* 0.810 6201 Field Control Electronics* 10.300 5308 Computer Hardware* 0.100 5101 Signal Distribution Equipment and Wiring* 0.410 5308 Foundation* 6.080 3610 Site Preparation* 0.200 1103 *Considered on site installation, not assembled at manufacturing site. Appropriate trade and transportation margins are those for sales to final demand. 256 Table A.3. Raw materials required for fabrication of one heliostat described in design report 2 (2) Purchaser's Price Material ($ 1976) I-O Sector Glass 551 3501 Support 309 4004 Hub 105 4004 Concrete* 100 3610 Low carbon steel 36 4004 Silver 20 3805 Adhesive 25 2704 Acrylic 20 2801 Cone* 137 4006 Sand* 17 900 Tracking & drive 780 4905 *See Table A.2 Table A.4. Energy required for heliostat delivery Transportation Energy Transportation (x 109 Btu Primary) Distance Design Report Design Report (Miles) 1 2 100 42 20 500 212 102 1,000 425 205 257 Receivers Raw material requirements The system of piping through which the working fluid is transported to and from the receiver (referred to as risers and downcomers) can be included in either the receiver or tower raw material requirements. The risers and downcomers are reported with the receivers in design report 1 and with the towers in design report 2. Tables A.5 and A.6 list the raw material requirements for the fabrication of the 15 receivers described in design report 1 and the 3 receivers described in design report 2, respectively. Delivery requirements A cost of $730,000 (1977) is reported in design report 1 for the delivery of the receivers (l). The price deflator for services is 1.883 $1977/$l967 (7), and the energy intensity coefficient for the truck transportation sector (6503) is 54,968 Btu primary per $1967 producer's price (5). The trade and transportation margins for sales to final demand are zero for sector 6503 (5). The energy required for receiver delivery as described in design 9 Btu primary. The report 1 is calculated to be 21 x 10 total weight of the three receivers described in design report 2 is 1200 tons (2). Table A.7 lists the energy required for delivery of the three receivers described in design report 2 as a function of the transportation distance. 258 Table A.5. Raw materials required for fabrication of the 15 receivers described in design report 1 (l) Purchaser's Price (x 106 $1977) Component I-O Sector Absorber 2.540 4006 Drum 0.400 4006 Doors, casing, lining and insulation 1.940 4006 Piping 1.880 4208 Support structure, platform* 5.520 4004 Instrumentation and control* 1.150 5305 Riser and horizontal piping to receiver* 8.610 4208 Field erections and installation* 4.250 1103 *See Table A.2 259 Table A.6. Raw materials required for fabrication of the 3 receivers described in design report 2 (2) Purchaser's Price Material (x 106 $1976) I-O Sector Tubing 3.600 4208 Support structure 0.375 4006 Insulation 0.900 3620 Table A.7. Energy required for delivery of receivers described in design report 2 Transportation Distance Transportation Energy (Miles) (x 109 Btu primary) 100 l 500 4 1000 8 260 Towers Raw material requirements Tables A.8 and A.9 list the raw materials required for fabrication of the 15 towers described in design report 1 and the 3 towers described in design report 2, respectively. Table A.8. Raw materials required for fabrication of the 15 towers described in design report 1 (l) Purchaser's Price 6 Component (x 10 $1977) I-O Sector Tower and platform 26.660 4004 Tower foundation and site preparation 4.800 3610 Table A.9. Raw material requirements for fabrication of the 3 towers described in design report 2 (2) Material Purchaser's Price I-O Sector (x 106 $1976) Steel structure 1.500 4004 Concrete 3.000 3610 Slip forms 1.500 3611 Risers and downcomers* 0.072 4208 *See Table A.2. 261 Delivery requirements The towers are assumed to be constructed at the system site. Thus, the towers do not have a delivery requirement. Application of Input-Output Analysis to Prototype Component Manufacturing Systems Comments Input-Output analysis is used to calculate the energy embodied in the non-delivered raw materials required for fabrication of prototype components. Heliostats Tables A.10 and A.11 list the deflation of helio- stat cost data, Table A.12 lists the required trade and transportation margins, and Tables A.13 and A.14 list the producer's prices and the embodied energies of raw materials required for heliostat fabrication. Note that the trade and transportation margins for sales to the auto industry are appropriate for raw materials used at the manufacturing site. 262 Table A.10. Deflation of heliostat cost data reported in design report 1 Purchaser's Price $1977 Purchaser's Price I-O Sector (x 106 $1977) §I§€7 (7) (x 106 $1967) 3501 9.010 1.647 5.471 4004 66.200 2.120 31.226 4905 36.220 1.958 18.498 5304 4.640 1.774 2.616 5305 5.740 1.774 3.236 5308 1.940 1.774 1.094 5101* 0.100 1.023 0.098 5308* 10.710 1.774 6.037 6201* 0.810 1.370 0.591 3610* 6.080 1.838 3.308 1103* 0.200 2.165 0.092 *See Table A.2. Table A.11. Deflation of heliostat cost data reported in design report 2 Purchaser's Price $1976 Purchaser's Price I-O Sector ($1976) §I967 (7) ($1967) 2704 25 2.575 9.709 2801 20 1.583 12.634 3501 551 1.603 343.731 3805 20 2.977 6.718 4004 450 1.953 230.415 4905 780 1.520 513.158 900* 17 1.674 10.155 3610* 100 1.721 58.106 4006* 137 1.953 70.148 *See Table A.2. 263 Trade and transportation margins Table A.12. I-O Sector Totals 6901 6902 6503 6504 6505 6506 (6) 6501 (Sales to Auto-Industry) 722900900 375208253 1 l 1 000000000 000000000 923700100 0 O. O O O O O 0 532158253 1 000000000 000000000 000000000 000000000 000000000 000000000 744600800 321020000 165600000 411030000 * ** 411545458 000000000 785809333 223344555 (5) (Sales to Final Demand) 0000000 2036637 3 2 0000000 0 0 0000100 0000000 0094537 1 0000000 0000000 0000000 0000000 0000000 8000000 0000000 0 O O 0 9041000 0000000 *No interaction with auto-industry, margins for sales to final demand used 264 Table A.13. Producer's prices and embodied energies of raw materials required for fabrication of the 23,310 heliostats described in design report 1 Embodied I-O Producgr's Price Btu Primar Egergy . Sector (x 10 $1967) (5) (x 10 Btu Primary) 3501 4.639 107405 498 4004 28.103 131635 3699 4905 17.018 63646 1083 5304 2.540 67105 170 5305 3.074 41307 127 5308 1.061 63182 67 6501 1.019 92917 95 6503 0.437 54968 24 6901 2.459 37501 92 1103* 0.092 85922 8 3610* 2.547 148220 378 5101* 0.092 40810 4 5308* 5.856 63182 370 6201* 0.550 48425 27 6503* 0.417 54968 23 6901* 2.361 37501 89 6902* 0.001 37329 O *See Table A.2 265 Table A.14. Producer's prices and embodied energies of raw materials required for fabrication of one heliostat described in design report 2 Embodied I-O Producer's Price Btu Primar Egergy Sector ($1967) (5) (x 10 Btu Primary) 2704 8.379 185521 1.588 2801 11.724 226289 2.653 3501 291.484 107405 31.306 3805 6.523 164813 1.075 4004 207.374 131635 27.298 4905 472.105 63646 30.048 6501 12.709 92917 1.181 6503 10.123 54968 0.556 6901 95.944 37501 3.598 700* 6.905 114908 0.793 3610* 44.742 148220 6.632 4006* 65.939 111172 7.331 6501* 2.225 92917 0.207 6503* 3.940 54968 0.217 6504* 0.812 262498 0.213 6901* 13.846 37501 0.519 *See Table A.2 266 Receivers Tables A.15 and A.16 list the deflation of the receiver cost data, Table A.17 lists the required trade and transportation margins and Tables A.18 and A.19 list the producer's prices and embodied energies of the raw materials required for receiver fabrication. Note that the appropriate trade and transportation margins for raw materials required at the manufacturing site are those for sales to the boiler shop industry. Table A.15. Deflation of receiver cost data reported in design report 1 I-O Purchaser's Price $1977 Purchaser's Price seetor (x 106 $1977) §I§€7 (x 106 $1967) 4006 4.880 1.977 2.468 4208 1.880 2.461 0.764 4208* 8.610 2.461 3.499 4004* 5.520 2.120 2.604 5305* 1.150 1.774 0.648 1103* 4.250 2.165 1.963 *See Table A.2 267 Table A.16. Deflation of receiver cost data described in design report 2 Purchaser's Purchaser's I-o Pglce $1976 Pglce Sector (x 10 $1976) H967 (7) (x 10 1967) 3620 0.900 1.808 0.498 4006 0.375 1.953 0.192 4208 3.600 2.365 1.522 Table A.17. Trade and transportation margins I-O Sector 6501 6503 6505 6506 6901 6902 Totals (Sales to Boiler Shop Industry) 3620 8.3 0.0 0.0 0.0 8.3 4006 0.9 0.6 0.0 0.0 1.9 4208 0 3 1.2 0.0 0.0 11.2 (Sales to Final Demand) 1103 0.0 0.0 0.0 0.0 0.0 4208 0.0 1.0 0.0 0.0 11.0 4004 3.0 2.0 0.0 0.0 5.0 5305 0.0 0.0 0.0 0.0 5.0 OOO OOO (5) 0000 .0 GOOD (6) 268 Table A.18. Producer's prices and embodied energies of raw materials required for fabrication of the 15 receivers described in design report 1 Embodied Producer's Energy I-O Pgice Btu Primary (x 109 Btu Sector (x 10 $1967) $1967 (5) Primary) 4006 2.384 111172 265 4208 0.667 78483 52 6501 0.025 92917 2 6503 0.024 54968 1 6901 0.132 37501 5 1103* 1.963 85922 169 4208* 3.079 78483 242 4004* 2.344 131635 309 5305* 0.616 41307 25 6501* 0.078 92917 7 6503* 0.087 54968 5 6901* 0.547 37501 21 *See Table A.2 269 Table A.19. Producer's prices and embodied energies of raw materials required for fabrication of the three receivers described in design report 2 Producer's I-O Préce Btu Primary» Embogied Energy Sector (x 10 $1967) $1967 (5) (x 10 Btu Primary) 3620 0.415 162859 68 4006 0.185 111172 21 4208 1.329 78483 104 6501 0.048 92917 4 6503 0.019 54968 1 6901 0.215 37501 8 270 Towers Tables A.20 and A.21 list the deflation of tower cost data, Table A.22 lists the required trade and transportation margins and Tables A.23 and A.24 list the producer's prices and embodied energies of the raw materials required for tower fabrication. Note that the trade and transportation margins for sales to the new construction industry are agmxpriate for raw materials required at the manufacturing site. Table A.20. Deflation of tower cost data reported in design report 1 I-O Purchaser's Price $1977 Purchaser's Price se°t°r (x 106 $1977) grgg; ‘7) (x 106 $1967) 3610 4.800 1.838 2.612 4004 26.660 2.120 12.575 Table A.21. Deflation of tower cost data reported in design report 2 I-O Purchaser's Price $1976 Purchaser's Price seetor (x 106 $1976) I§I§€7 (7) (x 106 $1967) 3610 3.000 1.721 1.743 3611 1.500 1.721 0.872 4004 1.500 2.050 0.732 4208* 0.072 2.374 0.030 *See Table A.2 271 Trade A.22. Trade and transportation margins I-O Sector 6501 6503 6504 6505 6506 7004 6901 6902 Totals (sales to new construction) (9) 3610 0.6 4.1 0 0 0 0 18.2 3.9 26.8 3611 0.1 0.1 0 0 0 0 10.8 4.5 15.5 4004 2.6 2.1 0 0.4 0 0 4.3 0 9.4 (sales to final demand) (5) 4208 0 1 0 0 0 0 11 0 12 Table A.23. Producer's prices and embodied energies of raw materials required for fabrication of the 15 towers described in design report 1 I ' . I-O Producgr s Price Btu Primar Embogied Energy Sector (X 10 $1967) (5) (x 10 Btu Primary) 3610 1.912 148220 283 4004 11.393 131635 1500 6501 0.343 92917 32 6503 0.371 54968 20 6505 0.050 222024 11 6901 1.016 37501 38 6902 0.102 37329 4 272 Table A.24. Producer's prices and embodied energies of raw materials required for fabrication of the three towers described in design report 2 I-O Produczr's Price Btu Primary Embogied Energy Sector (x 10 $1967) $1967 (5) (x 10 Btu Primary) 3610 1.276 148,220 189 3611 0.737 113,661 84 4004 0.663 131,635 87 6501 0.030 92,917 3 6503 0.088 54,968 5 6505 0.003 222,024 1 6901 0.443 37,501 17 6902 0.107 37,329 4 4208* 0.026 78,483 2 6503* 0.000 54,968 0 6901* 0.003 37,501 0 *See Table A.2 Summary of the application of input- output analysis to prototype component manufacturing systems Table A.25 lists the energies embodied in the non- delivered raw materials required at the manufacturing and the system sites, and the delivery energy requirements for distribution of the raw materials to the respective sites. o N om com m N III III moa mmha ma H mum309 III III ma mmH m m mm men m ham ma H mnm>flmomm 2. mm Nmm ONH VHHN oom.mm m 7 2 _HHH ems Ham mvwm oam.mm H mumumoflamm mamwumumz mamwumwmz wmnmcm pmum>flamplcoz CH mmhmcm Umum>fiamplcoz CH mum>flama pmflponem mmumcm >Hm>flamo pmflponfim wmumcm mufim Emumsm um mnflm manusuommscmz pm mnwmoewo wmmmwm wmmmmmwmw Umuflsvmm mamwumumz 3mm omuwsvmm mHMfluopmz 3mm Q 2 . Axumawum sum 0H xv wmnmcm pmwponsm m mucmcomeoo onDODOHm 0p Umfiammm mflmwamcm DDQDDOIDDQCH mo muasmmu mo mumafidm .mm.¢ magma 274 Application of the Disaggregation of the Energy Intensity Coefficients to Prototype Component Manufacturing Systems Tables A.26, A.27 and A.28 list the percentages of the total energy input of the analogous industries required for utilities (direct energy usage), capital, materials, services, trade and transportation (3). By assuming the energy embodied in the non-delivered raw materials required at the manufacturing site for fabrication of the prototype com- ponents represents the materials energy input, the remaining energy inputs can be estimated. Table A.29 lists the energy embodied in the non-delivered prototype components fabricated at the manufacturing site. Table A.26. Disaggregation of the auto-industry's energy intensity coefficient (sector 5903) (3) Component % Total Energy Requirement Direct Energy Usage 15.45 Capital 3.23 Materials 72.30 Transportation 1.52 Services 4.39 Trade 1.73 275 Table A.27. Disaggregation of the boiler shop industry's energy intensity coefficient (sector 4006) (3) Component % of Total Energy Requirement Direct Energy Usage 11.77 Capital 1.86 Materials 80.92 Transportation 1.14 Services 2.77 Trade 1.44 Table A.28. Disaggregation of the new construction industry's energy intensity coefficient (sector 1103) (3) Component % of Total Energy Requirement Direct Energy Usage 20.77 Capital 2.62 Materials 65.34 Transportation 2.31 Services 4.21 Trade 4.75 276 Table A.29. Energy embodied in non-delivered prototype components fabricated at the manufacturing site Design # of Embodied Energy Component Report Units (x 109 Btu Primary) Non-delivered Non-delivered Raw Materials Component Required at Fabricated at Manufacturing Manufacturing Site Site Heliostats 1 23,310 5645 7808 2 22,500 2114 2924 Receivers 1 15 317 392 2 3 193 239 Towers 1 15 1783 2729 2 3 360 551 277 Definition of the Nameplate Processing System The nameplate processing system is defined to be the Central Receiver Solar Thermal Power Station. The system consists of the heliostat field, controls for the Operation of the heliostat field, receivers, towers, the electric plant subsystem, thermal heat storage subsystem, facilities required for transportation of energy and materials between solar energy collection (i.e., helio- stats, receivers and towers), electric plant and thermal storage subsystems, and required general facilities. The inputs to the system are the required capital, a feed of solar radiation and raw materials consisting of the work- ing fluid, thermal storage materials and maintenance supplies. The system does not require an external supply of utilities. The output of the system is a non-distributed supply of intermediate to peak load electricity. Application of Process Analysis Comments The inputs and outputs of the systems are quanti— tatively identified according to the categories outlined in Chapter 3. Inputs Inputs 1-3 and 8-10 The energies embodied in the delivered, non-installed heliostats, receivers and towers (including the component 278 fabricated at the manufacturing site and additional mate- rials required at the system site) are estimated by extend- ing process analysis to conceptualized manufacturing systems. The remaining components and general facilities comprising the balance of the system are listed in Tables A.30 and A.3l. The energy required for the installation of components is estimated using information obtained from the disaggregation of the new construction industry's energy intensity coefficient. 279 Table A.30. Remaining components and general facilities required by the system described in design report 1 (1) Purchaser's Price 6 1-0 Component (x 10 $1977) Sector Thermal Storage Storage tanks & heaters 14.050 4006 Insulation 3.460 3620 Piping and supports 4.210 4208 Valves, strainers, filters 2.040 4208 Pumps 1.030 4901 Steam drums 0.190 4006 Heat exchangers 18.570 4006 Attemperators 0.040 4006 Support structure 0.140 4004 Instrumentation & control 0.220 5305 Foundations 0.080 3610 Safety protection equipment 0.080 5305 Turbine plant equipment Turbine generator 15.600 4301 Foundations 0.120 3620 Standby exciters 0.010 4907 Lubricating system 0.010 4907 Weather-proof housing 0.130 4006 Heat rejection equipment 4.050 4006 Condensing systems 1.500 4006 Regenerative heat exchangers 0.510 4006 Pumps 0.250 4901 Piping and tanks 0.400 4208 Water circulation/treatment systems 0.620 4907 Electric plant equipment Generator circuits 0.270 5303 Station service & startup transformers 0.810 5302 Auxiliary power sources 0.120 5304 Switchboards 0.020 5303 General station grouping systems 0.180 5305 Fire protection equipment 0.020 4907 Cathodic and freeze protection 0.100 5308 Electrical structure and wiring containers 0.720 5308 Power wiring 0.190 5308 280 Table A.30. Continued Purchaser's Price I-O Component (x 106 $1977) Sector Master control Computer 0.060 5101 Peripheral equipment 0.040 5305 Control panels and boards 0.490 5305 Interface equipment 0.120 5305 Control wiring 0.130 5308 Miscellaneous plant equipment Transportation & lifting equipment 1.200 4604 Air & water service systems 0.800 4907 Communication equipment 0.070 5604 Furnishings & fixtures 0.200 2307 Transmission plant equipment 0.420 5308 Other Contractor field office supplies* 0.910* 1103 Temporary construction* 2.440* 1103 Construction equipment 3.420 4501 Construction services 5.000 1103 Spare parts 2.050 4907 Yard work* 3.370* 1103 Turbine building* 0.800* 1103 Ad/control building* 0.800* 1103 Maintenance/warehouse building* 0.380* 1103 Fire pumphouse* 0.030* 1103 Condensate pumphouse* 0.020* 1103 Gate house* 0.010* 1103 *Represents a contract cost for services including materials, direct energy usage and capital required to construct the facility. 281 Table A.31. Remaining components and general facilities required by the system described in design report 2 (2) Purchaser's Price I-O Component (x 106 $1976) Sector Thermal storage (steel ingots) 23.940 4006 Turbogenerator 15.000 4301 Control system 9.500 5305 Electric plant 0.750 5308 Master control center* 0.250* 1103 Maintenance yard* 0.500* 1103 Waste treatment* 0.300* 1103 Motor pool (including vehicles) 0.200 5903 Rail heat 0.500 6104 Service road? 1.000* 1103 Land preparation* 3.500* 1103 Spare parts 5.000 4907 Cooling tower 7.000 4006 *See Table A.30 282 Inputs 4-5 The feed required by both systems is solar radiation. Neither system requires an external supply of utilities. The raw materials required by system 1 during the lifetime of the system are listed in Table A.32. The system described in design report 2 does not require raw materials in addition to maintenance supplies. Table A.32. Raw materials required by the system described in design report 1 (l) , . Producer s Price I-O Raw Material (x 106 $1977) Sector Thermal storage material 8.670 2701 Delivery cost 1.550 6503 Inputs 6-7 Neither system reports secondary or waste products requiring additional handling not included in the general facilities. The output of both systems is non-delivered electricity. Input 11 Table A.33 lists the annual expenditure for the maintenance of each system. The trade and transportation margins for the maintenance and repair sector (sector 1202) for sales to final demand are zero. Thus, the purchaser's 283 prices reported in the design reports are equal to the producer's prices for the maintenance services. Table A.33. Maintenance requirements Design Producer's I-O Report Prices Sector 1 2.385 x 106 $1977/year 1202 2 2 x 106 $1976/year 1202 Outputs A portion of the electricity produced in each system must be fed back for operation of the system. The system described in design report 1 requires a maximum electrical utility feedback of four per cent of the system's gross electrical output. The electrical feedback required by the system described in design report 2 is not reported and is assumed to be four per cent of the gross electrical output as well. Table A.34 lists the energy outputs of each system. Table A.34. Energy outputs of systems R t d Gross Energy Energy . a e . Output Output De51gn Output Capac1ty 9 9 Report MW(e) Factor (x 10 Btu/yr) (x 10 Btu/yr) l 150 0.5 2242 2153 2 100 0.5 1495 1435 284 Application of Input-Output Analysis Note that input-output analysis is applied to both annual and lifetime cost data. These data are analyzed separately to study the sensitivity of each system's energy characteristics to the system's lifetime. Table A.35 and Table A.36 list the deflation of cost data, Table A.37 lists the required trade and transportation margins, and Table A.38 and Table A.39 list the producer's prices and embodied energies of the remaining components, general facilities and maintenance requirements. Table A.40 lists a summary of the application of input-output analysis. 285 Table A.35. Deflation of cost data reported in design report 1 Purchaser's Purchaser's *See Table A.30 **Represents a producer's price I-O Pric: $1977 Pric: Sector (x 10 $1977) §I§€7 (7) (x 10 $1967) (lifetime cost data) * 1103 13.760 2.165 6.356 , 2307 0.200 1.788 0.112 ’ 2701** 8.670 1.905 4.551 3610 0.080 1.838 0.044 E 3620 3.580 1.705 2.100 E 4004 , 0.140 2.120 0.066 E 4006 39.040 1.977 19.747 h 4208 6.650 2.461 2.702 4604 1.200 1.964 0.611 4901 1.280 1.730 0.740 4907 3.510 1.932 1.817 5101 0.060 1.023 0.059 5302 0.810 1.460 0.555 5304 0.120 1.774 0.068 5305 1.130 1.774 0.637 5308 1.560 1.774 0.879 4301 15.600 1.970 7.919 4501 3.420 2.144 1.595 5303 0.290 1.729 0.168 5604 0.070 1.501 0.047 6503** 1.550 1.883 0.823 (annual cost data) 1202 2.385 1.883 1.267 286 Table A.36. Deflation of cost data reported in design report 2 Purchaser's Purchaser's I-O Price $1976 Price Sector (x 106 $1976) §I§€7 (7) (x 106 $1967) (lifetime cost data) 1103* 5.550 1.988 2.792 4006 30.940 1.953 15.842 4301 15.000 1.821 8.237 4907 5.000 1.520 3.289 5305 9.500 1.661 5.719 5308 0.750 1.661 0.452 5903 0.200 1.376 0.145 6104 0.500 1.645 0.304 (annual cost data) 1202 2.000 1.752 1.142 *See Table A.30 287 Table A.37. Trade and transportation margins (sales to final demand) (5) I-O Sector 6501 6503 6504 6505 6506 6901 6902 Total 1103 O 0 0 O 0 0 O 0 2307 6 4 0 0 O 12 O 22 3610 0 4 O 0 0 19 0 23 3620 10 3 O O 0 11 O 24 4004 3 2 0 0 O 5 0 10 4006 1 1 O O O 4 O 6 4208 O l O O 0 ll 0 12 4301 O O 0 O O 1 O l 4501 l l O O 0 12 0 14 4604 1 2 O O 0 5 O 8 4901 l 2 O O O 10 0 13 4907 O O 0 O O 7 O 7 5101 O O O O 0 5 1 6 5302 1 2 0 0 0 2 O 5 5303 O O O O O 6 l 7 5304 l O 0 O 0 2 1 4 5305 O O O O 0 5 O 5 5308 O 0 0 0 0 3 O 3 5604 O O 0 0 O l 1 2 5903 l l 0 O O 3 ll 16 6104 l O O 0 O l 0 2 pwflmmmfi 288 Table A.38. Producer's prices and embodied energies of remaining components, general facilities and maintenance services required by the system described in design report 1 Producer's Embodied I"0 Pricg Btu Primar Engrgy Sector (x 10 $1967) (5) (x 10 Btu Primary) (lifetime energy inputs) 1103* 6.356 85,922 546 2307 0.087 65,885 6 2701** 4.551 291,465 1326 3610 0.034 148,220 5 3620 1.596 162,859 260 4004 0.059 131,635 8 4006 18.562 111,172 2064 4208 2.378 78,483 187 4301 7.840 74,377 583 4501 1.372 72,010 99 4604 0.562 63,180 36 4901 0.644 59,006 38 4907 1.690 68,763 116 5101 0.055 40,810 2 5302 0.527 78,657 41 5303 0.156 49,712 8 5304 0.065 67,105 4 5305 0.605 41,307 25 5308 0.853 63,182 54 5604 0.046 34,870 2 6501 0.451 92,917 42 6503 0.350 54,968 19 6503** 0.820 54,968 45 6901 1.930 37,501 72 6902 0.003 37,329 0 (annual energy input) 1202 1.267 61,453 78 *See Table A.30 **Represents raw materials required by system described in design report 1 289 Table A.39. Producer's prices and embodied ener gies of remaining components, general facilities and maintenance services required by the system described in design report 2 Producer's Embodi I-O Pric: Btu Primar Energy Sector (x 10 $1967) (5) (x 10 ed Btu Primary) (lifetime energy inputs) 1103* 2.792 85,922 240 4006 14.891 111,172 1,655 4301 8.155 74,377 606 4907 3.059 68,763 210 5305 5.433 41,307 224 5308 0.438 63,182 28 5903 0.122 71,313 8 6104 0.298 116,790 35 6501 0.163 92,917 15 6503 0.160 54,968 8 6901 1.253 37,501 47 6902 0.016 37,329 1 (annual energy input) 1202 1.142 61,453 70 *See Table A.30 290 on HB ovN wth N mm mnH Nan mmmm H mpcocomfioo monocm meHuoumz 3mm cam mCHCHMEmm mocmcmuchz >Hm>HHoo mmHuHHHomm Hmnmcmo pmHHmpmcchoz pon>HHmplcoz omum>HHmplcoz Auw\mumaflum sum moH xv AxumEHHm sum mOH xv whommm usmcH >mumcm Hoocc< unmcH mouocm mEHumMHH cmHmwo wmnmcm UmHUOQEm l'llll ll 11'! i. I'I'I '.|'|..t mHmmHmcm unauDOIusmcH mo coHuMOHHmmm onu mo NHMEESm .ov.¢ mHnma ~- —J.. _‘_._.—-. 291 Application of the Disaggregation of Energy Intensity Coefficients The direct energy usage and the capital required to install the components at the system Site are estimated by assuming the installation energies to be similar to the energy requirements of the new construction industry (sector 1103). The energy embodied in the non-delivered, non-installed components are assumed to represent the material energy input of the new construction industry. Table A.28 lists the material input to be 65.34 percent of the sector's total energy input. Table A.4l lists the installation energy requirements. Table A.41. Energy required for the installation of components at the system site Energy Embodied in the Non-delivered Energy Required . Non-installed Components for Installation DeSign 9 . 9 . Report (x 10 Btu Primary) (x 10 Btu Primary) 1 15998 8486 2 6814 3615 —~ rrn-mmw APPENDIX B APPENDIX B ENERGY ANALYSIS OF THE PRODUCTION OF INDUSTRIAL PROCESS HEAT FROM SOLAR RADIATION General Approach There exist examples of systems that supply process heat (i.e., hot water, hot air or steam) from solar radiation currently in Operation for several indus- trial processes. Also, the solar collectors utilized in such systems are well developed in terms of the collector design and materials of construction that give reliable operation with minimal costs. As a result, the materials and components required in the design specifications of a proposed solar industrial process heat system can be defined with a high level of certainty. However, both the manufacture of the solar collector and the installation of the system are not well developed and current practices are far from optimal. The energy embodied in the solar collector and the energy required for installation of the system are estimated in the same manner as applied to the central receiver solar thermal power stations (i.e., the fabrication of collectors is assumed to be analogous to manufacturing practices utilized in the auto industry and the installation is assumed to be analogous to construction 292 of well-established industries and their embodied energies are estimated by the direct application of input-output analysis. It is common for designs of solar industrial pro- 293 practices utilized in the new construction industry). The remaining components required in the system are the products cess heat systems to ignore the raw material (i.e., working E fluid and maintenance supplies) and utility (i.e., electri- E city for operation of pumps, fans, etc.) requirements of the system. The energy embodied in the raw materials is usually a negligible energy input. However, the required electricity is not negligible. The importance of the utility requirement of the system is amplified by the fact that the input (electricity) is of a higher quality than the output (process heat) of the system. The utility requirement of systems that supply domestic hot water and space heating (established for the assessment of Operational data) has been observed to exceed the energy output of the system (1), usually as a result of improper instal- lation. Conversely, an electricity requirement of approximately five per cent of the system's heat output represents a superior system design and installation (1). The utility requirement is treated as a variable to study the sensitivity of the system's energy parameters to the utility requirement. The energy embodied in the delivered, non-installed solar collectors listed in Table B.l are determined in the 294 Emmum m m .uHm no: m « .uowm3 won m 3 “pmosooum amumcm NC Show I m u- o.m o.m o.m OH.m mcHumnucmocou cmsouu OHHonmumm 0H >.N n.N >.N HN.m mcHumnucmocoo mcwH chmmum ON 0.0 o.m o.m Hm.v mcwumuucmocoo coumcHB om o.m o.m o.m mm.m HMHOQOH poumsom>m mm m.w N.n 0.0 Hm.OH Hmmum OH O.N N.n v.N Ho.m EscHfisHm mm N.h N.h N.> No.v Monaco I mumHm HOHm mm m< m3 xmu>v Amuo\onm GOH xv Amow\nHv nooomHHoo uwwwwwwww SOHOOHHOO Mo OEHDOMHH OCHHOQ ouHm oHnmuomHHoo amumcm umHOm ocHusuomMscmz may um couscoum HHCD mo uanoz | 1.411- J'UIII ,I’Il I,‘,Il I , )l ... 1 v'lll ISA'. ll .ll-u Amy emumecm mpouowHHoo MOHOO mo coHumeommo .H.m oHnt 295 same manner as applied to the prototype components of the central receiver solar thermal power station. Energy analysis is then applied to the three solar industrial process heat systems listed in Table B.2. Description of Data Data describing the system and raw material re- quirements for collector fabrication are taken from system and collector evaluations performed by the Mitre Corpora- tion (2, 3). Raw material requirements for collector fabri- cation are described as the purchaser's price of components in 1976 and 1974 dollars. The remainder of the components required by each system are described as vendor quotes for the purchase of the components in terms of the purchaser's price in 1976 or 1974 dollars. There are no general facility, raw material (other than those included in the maintenance supplies) or utility requirements reported for the systems analyzed. The maintenance requirement of the system is reported as an annual expenditure for the purchaser's price of the service in 1976 dollars. Estimation of Energy Embodied in Collectors General Approach to the Estimation of the Energy Embodied in Solar Collectors The analysis utilized to estimate the energy embodied in the delivered, non-installed collectors is the same analysis applied to the prototype components of the 296 Table B.2. Description of system analyzed (2) System Description I Supply of 60-800C hot water using evacuated tubular collectors for textile plant in South Carolina II Supply of 80-1000C hot water using copper flat plate collectors for can-washing operation of a soup canning plant in Southern California III Supply of 100-1500C hot air using Winston concentrating collectors for plastic curing operation located in California Wfitfl 297 central receiver solar thermal power station. Refer to the General Approach for Extension of Process Analysis to Prototype Component Manufacturing Systems and the Definition of the Nameplate Processing Systems Responsible for the Manufacture Of Prototype Components in Appendix A for details. Application of Process Analysis to Solar Collectors Comments Process analysis is used to quantitatively identify the raw materials required for collector fabrication and the energy required for delivery of the collectors to the system site. Raw materials Table 8.3 lists the raw material requirements for fabrication of the collectors analyzed. Delivery requirements The solar collectors are assumed to be transported from the manufacturing site to the system site via truck transportation. Perry, et al., (5) report private inter- city trucking to require 7000 Btu primary per ton mile. Table B.4 lists the energy required for delivery of the collectors as a function of transportation distance (based on collector weights listed in Table B.1). 298 Table B.3. Raw materials required for fabrication of the collectors analyzed Purchaser's Price I-O Collector Component ($1976/ft2) Sector Flat Plate (2) Absorber - copper 2.25 4006 aluminum 1.35 3808 steel 2.50 4006 Selective coating- black chrome 0.70 2704 copper oxide 0.50 2704 Headers/tubes- copper 0.30 3807 aluminum 0.15 3808 steel 0.50 4208 Glazings (each)- glass 0.75 3501 tedlar 1.25 2801 Insulation- fiberglass 0.35 3620 foamglass 0.70 3620 Anti—reflective coating 0.50 2704 Collector box (steel) 0.30 4006 Evacuated Tubular (2) Glass 1.44 3501 Reflector 0.50 2704 Header (OOpper) 0.75 3807 Insulation 0.75 3620 Gasket 0.30 3618 299 Table B.3. Continued Purchaser's Price I-O Collector Component ($1976/ft2) Sector Winston Concentrating (2) Reflector (steel) 0.50 4006 Absorber (COpper) 0.75 4006 Selective coating 0.20 2704 Insulation 0.75 3620 Box 0.30 4006 Cover glass 0.75 3501 Sealant 0.30 2704 Fresnel Lens Concentrating (2) Lens (plastic) 3.40 2801 Absorber and coating 0.95 4006 Box 0.30 4006 Insulation 0.75 3620 Tracking mechanism 1.00 4905 Parabolic Trough Concentrating (3) Support structure a steel structure 1.09 4004 concrete founda- a tion * 0.36 3610 Trough mirror and support reflective surface (alzac aluminum) 1.66 3808 aluminum support 1.92 3808 Receiver a pyrex tube 2.13a 3501 absorber pipe 0.31a 3808 selective coating 0.44 2704 300 Table B.3. Continued Collector Component Purchaser's Price I-O ($1976/ft2) Sector Parabolic Trough Tracking Concentrating (3) mechanism (Continued) gears 2.00: 4905 bearing 0.66 4902 chain 0.24a 4907 motors and sensors 1.00: 5304 miscellaneous 1.45 4907 a — Value has units of @1974/ft2) *Not a raw material required at the manufacturing site. Table B.4. Energy required to deliver collectors 301 Transportation Energy (Btu Primary/ftz) Collector 50 mi 100 mia 500 mia Flat Plate Copper 807 1614 8068 Aluminum 877 1754 8768 Steel 2959 5919 29593 Evacuated Tubular 1043 2086 10430 Winston Concentrating 789 1579 7893 Fresnel Lens Concentrating 562 1124 5618 Parabolic Trough Concentrating 1593 3185 15925 a - Transportation distance 302 Application of Input-Output Analysis to Solar Collectors Table B.5 lists the deflation of collector cost data, Table 8.6 lists the required trade and transportation margins and Table B.7 lists the producer's prices and embodied energies of the raw materials required for col- lector fabrication. Summary of Results of the Application of Input-Output Analysis to Solar Collectors Table B.8 lists the energy embodied in the non- delivered raw materials required at the manufacturing site and the system site and the energy required for delivery of the raw materials required at the system site. Application of the Disaggregation of Energy Intensity Coefficients to the Solar Collectors The total energy embodied in the non-delivered collector is estimated by assuming the energy embodied in the non-delivered raw materials required for collector fabrication is analogous to the material energy contribution to the total energy requirement of the auto industry (sector 5903) Inspection of the disaggregation of the auto industry's energy intensity coefficient (see Table A.26) gives the material contribution to be 72.30 per cent of the sector's total energy requirement (4). Table B.9 lists the total energy embodied in the non-delivered collectors fabricated at the manufacturing site. 303 Table B.5. Deflation of collector cost data Purchaser's Purchaser's I-O Price 2 $1976 Price Collector Sector ($1976/ft ) $I967 (9)($1967/ft2) Flat Plate 2704: 1.20 2.575 0.466 2704 1.00 2.575 0.388 2801 1.25 1.583 0.790 3501C 0.75 1.603 0.468 3620d 0.70 1.808 0.387 36206 0.35 1.808 0.194 3807f 0.30 1.658 0.181 3808 1.58 1.822 0.823 42083 0.50 2.365 0.211 4006. 2.50 1.953 1.280 40061 2.25 1.953 1.152 4006 0.30 1.953 0.154 Evacuated 2704 0.50 2.575 0.194 Tubular 3501 1.44 1.603 0.898 3807 0.30 1.808 0.166 3620 0.75 1.808 0.415 3618 0.75 1.658 0.452 Winston 2704 0.50 2.575 0.194 Concentrating 3501 0.75 1.603 0.468 3620 0.75 1.808 0.415 4006 1.55 1.953 0.794 Fresnel Lens 2801 3.40 1.583 2.148 Concentrating 3620 0.75 1.808 0.415 4006 1.20 1.953 0.640 4905 1.00 1.520 0.658 Parabolic Trough 2704 0.44? 1.720% 0.256 Concentrating 3501 2.13? 1.490k 1.430 3808 3.891 1.505k 2.585 4004 1.09? 1.646k 0.662 4902 0.66? 1.393k 0.474 4905 2.00? 1.464k 1.366 4907 1.69? 1.474k 1.147 5304 1.00? 1.404k 0.712 3610* 0.363 1.513 0.238 304 Table B.5. Continued a through i - Variations in Flat Plate collector design a — black chrome selective coating b - copper oxide selective coating c - foamglass insulation d - fiberglass insulation e - copper headers/tubes f — aluminum absorber, headers/tubes g - steel headers/tubes h - steel absorber i - copper absorber j - value has units of ($1974/ft2) k - Value has units of ($1974/$l967) * - See Table B.3 305 Table B.6. Trade and transportation margins I-O Sector 6501 6503 6504 6505 6506 6901 6902 Totals (sales to auto industry) (8) 2704 4 4 0 0 0 6 0 14 2801 2 2 0 0 0 3 0 7 , 3501 2 l 0 0 0 12 0 15 3618 9 0 0 0 0 7 0 16 3620* 10 3 0 0 0 ll 0 24 3807 l l 0 0 0 2 0 4 3808 1 1 0 0 0 3 0 5 4004* 3 2 0 0 0 5 0 10 4006* 1 1 0 0 0 4 0 6 4208* 0 l 0 0 0 ll 0 12 4902 0 1 0 0 0 7 0 8 4905 0 0 0 0 0 8 0 8 4907* 0 0 0 0 0 7 0 7 5304 0 1 0 0 0 2 0 3 (sales to final demand) (7) 3610 0 4 0 0 0 19 0 23 *NO interaction with auto industry - sales to final demand used 306 Table B.7. Producer's prices and embodied energies of raw materials required for collector fabrication Embodied Producer's Energy I-O Price 2 Btu Primarz, (x 10 Btu . Collector Sector ($1967/ft ) $1967 (7) primary/ft‘) Flat Plate 2704: 0.401 189521 76 2704 0.334 189521 63 2801 0.735 226289 166 3501C 0.398 107405 43 3620d 0.294 162859 48 3620 0.147 162859 24 3807: 0.174 107150 19 3808 0.782 256521 201 42083 0.186 78483 15 4006. 1.203 111172 134 40061 1.083 111172 120 4006 0.145 111172 16 6501 0.156 92917 15 6503 0.113 54968 6 6902 0.362 37501 14 Evacuated 2704 0.167 189521 32 Tubular 3501 0.763 107405 82 3807 0.434 107150 46 3620 0.315 162859 51 3618 0.139 88343 12 6501 0.087 92917 8 6503 0.034 54968 2 6902 0.186 37501 7 Winston 2704 0.167 189521 32 Concentrating 3501 0.398 107405 43 3620 0.315 162859 51 4006 0.746 111172 83 6501 0.067 92917 6 6503 0.033 54968 2 6901 0.145 37501 5 Fresnel Lens 2801 1.998 226289 452 Concentrating 3620 0.315 162859 51 4006 0.602 111172 67 4905 0.605 63646 39 6501 0.091 92917 8 6503 0.062 54968 3 6901 0.188 37501 7 ill (’I ..I: {II 111 1 .{l I ..llll!:lll|1{ 307 Table B.7. Continued Embodied Producer's Energy I-O Price 2 Btu Primar (x 10 Btu 2 Collector Sector ($1967/ft ) $1967 57) primary/ft ) Parabolic 2704 0.220 189521 42 Trough 3501 1.216 107405 131 Concentrating 3808 2.456 256521 630 4004 0.596 131635 78 4902 0.436 85795 37 4905 1.257 63646 80 4907 1.067 68763 73 5304 0.691 41307 29 6501 0.085 92917 8 6503 0.085 54968 5 6901 0.580 37501 22 3610* 0.183 148220 27 6503* 0.010 54968 1 6901* 0.045 37501 2 a through i - See Table 8.5 *See Table B.3 IIIIIIIIIIIIHHHIIIIIIIIIIIIIJHWIFE? P. ”M. 308 Ammaomu mco .mmmam mcov mmcwnmam 03» can cofipmasmcw mmmamumnwm .mcfiumoo m>fluomamm mwflxo memoo m mmuflaflus Houowaaoo mmfizmmd I m m hm OOHH mcflumuucmoaoo canons owaonmumm III III moo mcwumuucwocoo mama Hmcmmum III III mom mcflumuucmocoo coumcflz III III mmm HMHSQDB cmumnom>m III III How mamwum III III mam madcflEdam III III Hmv muwmmou mamam umHm mpflm smummm muam mnu um Umuflsvmm mpflm Emummm mcwusuommscmz maneumymz 3mm mcp pm Umuflsvmm map um omuflsvmm mo >um>flawo MOM mamfiumumz 3mm maneuwumz 30m Umuflsgmm mmumcm wmum>flamoIcoz owum>fiamcIcoz Amom\>umeflnm sum OH xv mmumcm U®Hb035m uouomaaou m I‘III' . I'll msouomaaoo HmHOm 03¢ ou mflmwamcm usmuso Ignace mo coflumowammm 0:» mo muasmmh mo humEEDm .m.m GHQMB 309 Table B.9. Energy embodied in the non—delivered collectors fabricated at the manufacturing site Embodied Energy (x 103 Btu primary/ftz) Non-delivered Non-delivered Collector Raw Materials Collector Flat Plate Copper 451 624 Aluminum 513 710 Steel 461 638 Evacuated Tubular 223 308 Winston Concentrating 209 289 Fresnel Lens Concentrating 609 842 Parabolic Trough Concentrating 1100 1521 310 Definition of Nameplate Processing System Solar industrial process heat systems are usually designed to interface with existing processes to displace other fuels utilized to supply process heat. Solar industrial process heat systems are actually utility sup- ply systems. Thus, the process heat is consumed at its production site and does not require transportation facili- ties in addition to the system itself. As a utility supply system, the nameplate processing system consists of the solar collectors, pumps or fans and plumbing required to interface the solar process heat system with the existing system, materials (including support structure of the col- lector array) required to install the solar process heat system and any additional controls required for system Operation. The obvious output of the solar process heat system is thermal energy. However, as a fuel displacement system, the output of the system is the energy embodied in the fuel it displaces. The fuel savings output will exceed the thermal output of the solar process heat system due to the energy subsidy of the displaced fuel and the thermal losses occurred during consumption of the displaced fuel for production of the process heat. This analysis considers the output of the solar process heat systems to be the thermal energy produced. Thus, the energy parameters resulting from the analysis represent the lower bounds of the energy characteristics of the systems. 311 Application of Process Analysis Inputs The inputs to the nameplate processing system are identified according to the categories outlined in Chapter 3. Inputs 1-3, 8-10 Table B.10 and Table B.1l list the collectors and their embodied energies and the additional components required by the systems analyzed, respectively. The energies required to install the components are estimated using information obtained from the disaggregation of the energy intensity coefficients. Inputs 4-5 The feed to each system is freely available solar radiation. The energies embodied in raw materials not included in the maintenance supplies are considered to be negligible. Each system has an electrical utility require- ment reported as a percentage of the system's thermal out- put. The utility requirement of each system is varied (5, 10 and 20 per cent of the thermal output required as an electrical input) to study the system's energy parameters' sensitivity to the utility requirement. 312 @Ofiwfimflfi COflHMUHOQmCMHu. I M H.H N.o H.O mm ooo.mma mcflumuuamocoo coumcflz HHH N.H N.o H.O «a ooo.oma wumam umam Hmamoo HH m.m m.o m.o up moa x m.m amasnsu omumsom>m H mflE oom was OOH mHE om uoyomaaou Amumv £3 uouomaaoo Emumam UmaamumcfiIcoz pcmEmHquwm >Hm>wamo Umum>flawplcoz Amvpmnflsqmm mound mommnsm Azumeflum sum moa xv mmnwcm pwflponam m>auomammm IIIOIIIIIIIIIIII Il'lllln'.‘ .IOI I.'I‘V II III IlI..l|‘ 1'14I «III'illIIIIIIII I powwamcm mEmumwm mnu an pmuflsqmu mHOpomHHou .oa.m magma 313 Table B.11. Remaining components required by the systems analyzed (2) Purchaser's Price I-O System Components (x 103 $1976) Sector I Plumbing 83.300 4208 Valves 28.800 4208 Pumps 28.800 4901 Control 12.500 5305 Storage 243.800 4006 II Pumps 7.000 4901 Valves 7.000 4208 Plumbing 42.000 4208 Controls 12.000 5305 III Ductwork 18.300 4006 Valves 7.300 4208 Controls 13.500 5305 Fans 8.600 4903 Storage 142.500 4006 Heat Exchangers 86.400 4006 314 Inputs 6-7 None of the systems have reported secondary or waste products. The primary product of each system is thermal energy consumed at its production site. Input 11 Table B.12 lisusthe annual expenditures for the maintenance of the systems analyzed. Table 8.12. Annual maintenance requirements (2) , . Purchaser s Price I—O System (x 103 $1976/yr) Sector I 17.800 1202 II 21.600 1202 III 27.132 1202 Outputs Table B.13 lists the energy outputs of the systems analyzed. Table B.13. Annual energy outputs of systems analyzed (2) Thermal Energy Output 6 System (x 10 Btu/yr) I 67,850 II 38,250 III 29,565 315 Application of Input-Output Analysis Table B.14 lists the deflation of remaining components and maintenance cost data, Table B.15 lists the required trade and transportation margins and Table B.16 lists the producer's prices and embodied energies of the remaining components and maintenance requirements. Table B.17 lists the energy contents and embodied energies of the utility requirements. Note that the trade and transportation margins for the electrical utility sector are zero. Thus, the energy required for the delivery of electricity is negligible. Table B.14. Deflation of remaining component and maintenance cost data Purchaser's Price Purchaser's Price I-O 3 $1976 3 System Sector (x 10 $1976) $1967 (9) (x 10 $1967) (lifetime cost data) I 4208 112.100 2.365 47.400 4006 243.800 1.953 124.834 4901 28.800 1.520 18.947 5305 12.500 1.661 7.526 II 4208 49.000 2.365 20.719 4901 7.000 1.520 4.605 5305 12.000 1.661 7.225 III 4006 247.200 1.953 126.575 4208 7.300 2.365 3.087 4903 8.600 1.520 5.658 5305 13.500 1.661 8.128 (annual cost data) I 1202 17.800 1.752 10.160 II 1202 21.160 1.752 12.078 III 1202 27.132 1.752 15.486 316 Table B.15. Trade and transportation margins (7) (sales to final demand) I-O Sector 6501 6503 6504 6505 6506 6901 6902 Totals (% of purchaser's price) 1202 0 0 O O O 0 O 0 4006 l l O 0 0 4 0 6 4208 O l 0 O 0 ll 0 12 4903 O l O 0 O 7 O 8 5305 O O O 0 O 5 0 5 6 ($1967/x lO Btu) 6801 0 0 0 0 0 O 0 0 317 mmm mmvao www.ma «ONH HHH new mmeaw mno.~a mama HH «No mmvam omH.oa moma H Audacfl mmnmcm Hmsccwv mmm Homhm mom.w Home v» momvm mmm.a momm maa hammm oom.a Home mam homav mmh.h momm nvm mnmmm mom.m momv mam mmvmn haw.m momv nmmma NBHHHH Hmm.maa ooow HHH baa Homnm HOH.m Home ma mwmvm mmm.o momm v hammm mqo.o Home «mm nomav vom.o momm wmm moomm ooo.v Homv Hmva mmvmn mmm.ma momv HH mow Hommm www.ma Home mHH mwmvm Hoa.m momm «ma nammm mmv.a Home mom nomav oma.b momm mum ooomm www.ma Home mvoma NBHHHH vvm.naa moov vnmm mmvmn man.av momv H Ausmcw mmumcm mEHumMHHV lawmafium sum 80H xv Ass somaw Asmmfim mod xv Honomm 800mmm wumaaum sum oIH mmuwcm @mHUOQEm moflum w.uwo:©oum mucmEmHHDUmu mocmcquHmE paw mucmcomeoo maficwmawu mo mwflquwcm Umflponaw cam mmoflum m.HmUDUOum .mH.m wanna 318 -IIIIIIII Illtfitiillh I- - OOO.mN Hmmm.m OOO.m ON oom.HH Hmmm.m OOO.m OH OOm.m Hmmm.m oom.H m HHH oom.mm Hmmm.m OOh.h ON OOO.vH Hmmm.m oom.m OH OOV.> Hmmm.m OOO.H m HH OOO.mm Hmmm.m OOO.MH om OOV.ON Hmmm.m OO0.0 OH OON.MH Hmmm.m oov.m m H AH%\NHMEHHm sum OOH xVAnV OHHuome sum AHN\sum OOH xv uDQWDOINmuwcm Emummm mmuwcm pmHUODEm mwmeflum sum ucmEmHHqum HmEumze m0 ammo Hmm HMOHHuomHm mpcmEmHqumu >uHHHpD Umum>HHm© CH pmHGOQEm mmumcm HMSCCfl .hH.m manna 319 Summary of Results of Input-Output Analysis Table B.18 lists the embodied energies of the non- delivered, non-installed remaining components and their delivery requirements, and the annual embodied energies of the delivered maintenance and utility requirements. Table B.18. Summary of the results of input- output analysis S stem Embodied Energies AY Lifetime Inputs (x 106 Btu Primary) non-delivered non-installed Annual Inputs (x 106 Btu Primary/yr) utility and remaining delivery maintenance components requirement requirement 53% 10a% 2038 I 17587 717 13824 27024 53524 II 1951 136 8142. 15642 30542 III 14106 425 6752 12452 23952 a - % of thermal output required as electrical input WI—lfiy -—— 320 Application of the Disaggregation of Energy Intensity Coefficients The energy required to install the components of each system are estimated by assuming the energy em- bodied in the non-delivered, non-installed components of each system is analogous to the material contribution to the total energy requirement of the new construction industry (sector 1103). Inspection of the disaggregation of the new construction industry's energy intensity coef- ficient gives the material input to be 65.34 per cent of the industry's total energy requirement (4) (see Table A.28). Table B.19 lists the energy embodied in the non- delivered, non-installed components and the energy embodied in the installed, non-delivered components. Table B.19. Energy embodied in the installed, non- delivered components of the systems analyzed Embodied Energy (x 106 Btu Primary) non-delivered installed, non-delivered System non-installed components components I 94,587 144761 II 95,551 146237 III 53,121 81299 - ".4, ..‘- ---- [Wiggly ‘II. APPENDIX C APPENDIX C ENERGY ANALYSIS OF CROP PRODUCING SYSTEMS General Approach When viewed as an energy supply system,crop pro- duction can be envisioned as a process that converts solar radiation into stored chemical energy as biomass. Thus, the feed to the system is solar radiation; the raw materials are seeds, fertilizers, chemicals and water; the utilities are motor fuels and electricity; and the capital is farm equipment. The inputs required for the production of a specific crOp are dictated by the cultural practices followed for the planting, growth, harvesting, collection, processing and delivery of the crop. Western cultural practices for crOp production are generaLurintensive (i.e., commercial fertilizers are extensively used and farm operations are automated with machinery replacing human labor wherever possible) with the goal of maximizing crOp yield per unit area of land in order to supply a rapidly growing population with food. The same intensive cultural practices are being considered for crOp produc- tion as an energy resource with the rationalization that such cultural practices will be required to provide enough 321 322 energy to make a significant contribution in the supply of energy for the United States. It is critical that the energetic characteristics of the supply of energy from biomass in a nation-wide role be understood prior to the formulation and implementation of such an energy policy. Thus, the cultural practices adopted for this energy analy- sis represent the most effective use of commercial fertili- zers and automated farming operation resulting in maximum crop yields without irrigation. It is suspected that a large portion of the energy subsidy required for intensive crop production originates from fertilizers, agricultural chemicals and seeds. The standard industrial classification of a 357 sector economy (1) allots single sectors for all fertilizers and general agricultural chemicals. Thus, it is necessary to extend process analysis to estimate the energies embodied in the various fertilizers, chemicals and seeds required for production of the crops analyzed. The results of the application of process analysis to various fertilizers, agricultural chemicals and seeds reported by Roller and Keener (2) are listed in Table C.1. Note that the unit energy equivalence is defined to be a MJ of thermal energy for the raw materials listed in Table C.1. In general, fertilizers and agricultural chemicals have little embodied electrical energy. For example, the electrical energy contributions to the total embodied primary energies of the fertilizers (sector 2702) 4 "9 O ._ g... 323 Table C.1. Energy embodied in various fertilizers, agricultural chemicals and seeds reported by Roller and Keener (2) Embodied Energy Raw Material (MJ thermal/kg) Nitrogen 64.40 P205 11.96 ' K20 11.96 :- Lime 0.28 E Herbicides 101.20 5: Insecticides 101.20 Alfalfa seeds 31.84 Corn seeds 7.37 Kenaf seeds 25.23 Slash pine planting trees 0.26 MJ/tree Wheat seeds 5.07 Napier grass seeds a a - Keener and Roller do not report a value for the energy embodied in napier grass seeds. They do, however, report a seed energy requirement of 1791.9 MJ thermal/hm per growth cycle for production of napier grass 324 and the agricultural chemicals (sector 2703) producing sectors are less than ten per cent (10). Thus, the embodied thermal energies reported in Table C.l are assumed to be equivalent to the embodied primary energy. The energies embodied in the non-delivered capital and utilities are estimated through input-output analysis. The energies required for delivery of the capital, raw materials and utilities (excluding electricity), as well as the energy required to transport the produced biomass (as collected and stored on the farmstead) to its end- use site, are estimated through an extension of process analysis. Perry, et al., (3) report for-hire truck transportation to require 5,000 Btu primary per ton-mile of work. The capital, raw materials and utilities are assumed to be transported an average of 500 miles by truck to the farmstead. The transportation distance of the delivery of the produced biomass to its end-use site is varied in order to study the sensitivity of the energy parameters of crOp production to the transportation dis- tance of the delivery of the produced biomass. The products of the crop producing systems analyzed are considered to be an energy fuel, in the form of biomass, ready for consumption. Thus, the processing of the bio- mass is comprised of chipping and drying operations. Blankenhorn, et al., (4) report chipping and drying operations to consume 84.3 MJ electric per tonne dry 325 biomass and 2790 MJ thermal per tonne water removed, respectively. The energy consumed during the chipping and drying operations is the utility requirement of the operations. Assuming the capital and raw material require- ments of the operations are negligible energy inputs, the total energy required for chipping and drying is the energy embodied in the energy consumed. Description of Data W‘JW'“ The analysis is based on the equipment, seed, fertilizer, chemical, fuel and electricity requirements for the production of various crops reported by Roller and Keener (2). The material and equipment requirements represent intensive crop production cultural practices and the fertilization usage represents the maximum crOp yields possible without irrigation. The fertilizer and chemical requirements are reported as kg per hm2 per growth cycle of nitrogen, P205, K205, lime, herbicides and insecticides. The fuel requirement is reported as liters of motor fuel per hm2 per growth cycle (assumed to be diesel fuel) and the electricity requirement is reported as 17 kwh per hm2 per year (excluding production of slash pine). The equipment requirement is reported as both the actual units and the cost (in 1974 dollars purchaser's price) of equipment utilized for crOp production from an area of 162 hm2 per growth cycle. The fraction of the equipment's embodied energy depleted 326 per hm2 during its service for crop production is considered to be the embodied energy of the delivered equipment required divided by 162 hm2 and multiplied by the ratio of the growth cycle Of the crOp and the life span of the equipment (8 years). Table C.2 lists the crops analyzed and the characteristics of each. Definition of Nameplate Processing System The nameplate processing system is defined to include all equipment, fertilizers, chemicals, fuels and electricity used at the farmstead for farming Operations. It is not defined to include any general facilities associated with the farm operations, such as housing or work sheds. Note that while the general facilities used to maintain the equipment and store the crops are not included in the nameplate processing system, the elec- tricity required to Operate these general facilities are. This is an acceptable definition of system boundaries since the life spans of the general facilities are much longer than the growth cycles such that the energy contribution from the general facilities is negligible. The output of the nameplate processing system is the harvested, collected and stored cr0p on the farmstead. The crop is then transported from the farmstead to the end-use site where processing of the crop is assumed to occur. Thus, process analysis must be extended forward film—I- 11?, "I‘ mmmuoum OHOMOQ Ummumaumm may um wupmum Ou UmonHm choc mo ucmucoo musumHOz I n ucmHm OHO£3 map mo uanmz haw man :0 comma mw msHm> I m Amy OH H om.nH mm.n OHcO pawns Avv mm ON OO.>H ON.OON mcmeHsOH mch nmmHm Amy mH m mo.eH om.HmH oon chumsm mmmuo Hmflmmz 7 Mu Hmv mH H O0.0H om.mH OOHHOHm mmcmm Amvan H 50.mH Om.mH OHnO cH00 Amy mH m mh.nH mv.om OHSO OMHme¢ va Aumv Amx\nzv AOHO>O nuBOHm Env Amy coHuODUOHm mono Hmwmmm umzvamv mHowo Amy pampcoo mmumcm m m0 COHHMOOH m A mccou v ucmucoo :u30uw A V OHOH» musumHoz m m . Ummemcm wmouo one mo mucmpcoo OHDDmHOE cam meo>o :u3oum .mucmpcoo wmumcm .coHDOSOOHQ mo :OHumOOH .mprHm Owuommxm .~.o anme 328 along the horizontal trajectory to determine the energy requirements for delivery and processing of the products. Application of Process Analysis Nameplate Processing System Comments The inputs and outputs of the nameplate processing system are quantitatively identified according to the categories outlined in Chapter 3. Inputs Inputs 1-3 Table C.3 lists the quantity of specific farm equipment required for the production of the various crops analyzed from 162 hm2 of land during the growth cycle of each crop. Table C.4 lists the tOtal weight and purchaser's price of the equipment required for the production of each crop. Installation of the farm equipment is not required. Inputs 4-5 The feeds to the crop producing systems are solar radiation. Tables C.5 and C.6 list the raw materials and utilities required for crop production, respectively. 329 III N III III III III OH 3mm GHmno m III N m m m mHmH commz common III III III III III III mmmH umumm>umn wmmuom 3OHI~ H III H H H H vmmH “mumm>umn wmmuOm uso uomuwa III III III III III III omn HcH OmIOV Bo Ow .uoum>HuHsu H H H H H H «me Any OHV s o.m .umsmumm III H III III III III wmm umucmHm cone H III III H H III mmmH HOH omIOV So we youGMHm choc III III H III III H own Hum m.mv E O.N .HHHHU comm H H H H H H emm 10m «HO 5 e.m .nuooumaHumm H H H H H H SOOH Hum NHV E h.m .omHO III H III III III III omm Hum so a H.~ .3oHd HmmHno H III H H H H mmm HGH OHIvO so ov 3OHQ OHMOQOHOS III H III III III III nmhm uouomuu Omewcs.mcHOUme m H m m m m emem uouomup mm on umwnz mch mmmuw mmcmx chow MMHmmHa mev “Has :mmHm HmHmmz UHcD mo mono mo coHuospoum qu uanmz UOHHDqOm muHCD mo HODEDZ '1 III 1 'I 1 1111‘ 1’01 Amy UmNmHmcm mmouo on» mo COHuODUOHQ MOM OOHHDOOH uch some mo HmuHcs mo Hones: ..O.HV mmHqucmzq mnu cam ucmEdeqm EHOM OHMHome mo muanOB .m.0 mHnme 330 Table C.4. Total weight and the purchaser's price of equipment required for production of the crOps analyzed from 162 hm2 per growth cycle (2) Weight of Purchaser's I-O Equipment2 Price 2 Crop Sector ‘Siéiii 23.1.) $33,312,332) Alfalfa 4400 15,677 43,850 Corn 4400 16,286 45,170 Kenaf 4400 16,286 45,170 Napier Grass 4400 15,677 43,850 Slash Pine 4400 10,004 32,550 Wheat 4400 16,286 43,000 331 Table C.5. Quantities of seed, fertilizer, and chemicals required for production Of crops analyzed (2) Quantity Required for CrOp Production (kg/hm2 growth cycle) Raw Napier Slash Material Alfalfa Corn Kenaf Grass Pine Wheat Seed 13.4 16.8 9.0 a 3400 112.0 trees Nitrogen --- 235.0 200.0 1674.0 1400.0 115.0 P205 446.0 110.0 99.0 1402.0 261.0 40.0 K20 1233.0 193.0 209.0 2382.0 464.0 62.0 Lime 4130.0 1320.0 1230.0 4650.0 8400.0 1230.0 Herbicides and Insecticides 13.4 4.5 4.5 4.5 4.5 --- a - Production Of napier grass has a seed energy requirement Of 1791 MJ primary/hm growing cycle (2) “1". 332 Hes :3x\nz oo.m mH muHoHuuome mo 33x O HO mocme>Hsvm mmnmcm HmEHmza I Q HOV H\Oz m.mm mH HOSM HmmmHU mo ucmucoo mmumcm HmEHmna I m N.HO O.hH N.OO>.N O.Hb “mun: N.Hw O.hH m.mnm.vm O.mN¢.H mch smMHm m.mmH O.Hm m.mmm.eH 0.048 mmmuo umHmmz N.HO 0.0H n.mmo.m H.Om MOGOM N.HO 0.0H 0.0borm 0.0m CHOU m.mmH , O.Hm m.mvv.HH m.>mm MHHmMHd AOHONO cpzoummscv HOHO>O cuzoumINELV AwHomo cu3oum NESV HOHO>O £u3oum NWSV mOHU A O: v A 33x v.4 O: O A mumuHH v Qucmucoo wmumcm wuHucmso mucwucoo wmuwcm huwucmso wmumsqmmequHuuomHm pmuqumm Hmsm HmmmHo Amy pmumecm wmouo mo coHuOSUoum HOH OOHHDUOH mmHHHHHu: mo mucmuaoo mmumcm tam mmHuHucmso .O.U OHQMB 333 Inputs 6-7 Crop production has no secondary products or waste products requiring special handling facilities. Inputs 8-10 The definition of the nameplate processing system does not include any general facilities. Input 11 The energy embodied in the required maintenance of the farm equipment (in addition to the electrical require- ment for operation of the farm shop) is assumed to be a negligible energy input. Outputs Table C.7 lists the energy outputs Of the crop producing systems. Table C.7. Energy outputs of crop producing systems Crop Energy Output (MJ/hm2 growing cycle) Alfalfa 645,500 Corn 348,800 Kenaf 331,500 Napier Grass 2,587,600 Slash Pine 4,933,400 Wheat 128,600 lmml'tt'nfimfi" 334 Extension of Process Analysis Energy embod ied in raw materials Tabl delivered ra e C.8 lists the energy embodied in the non- w materials required for crop production. Table C.8. Energy embodied in the non-delivered raw materials required for crop production Energy Embodied in Non-delivered Raw Materials Crop (MJ‘primary/hm2 growth cycle) Alfalfa 23,020 Corn 19,707 Kenaf 17,590 Napier Grass 156,612 Slash Pine 102,529 Wheat 9,538 nu! _ Mum; .1 335 Deliveryfirequirements Delivery of inputs The energies required for delivery of the inputs required for crOp production are estimated according to the weights of the capital (equipment), raw materials and utilities, a delivery distance of 500 miles and an energy requirement of 0.00581 MJ primary/kg-mile for truck transportation (3). A specific gravity of 0.8491 kg/liter is assumed for diesel fuel (7) and a weight Of 5 kg per planter is assumed for slash pine planter trees. The energy required for the delivery of electricity is assumed to be negligible and the weight of equipment to be delivered is calculated as the total weight of equipment required for crOp production from 162 hm2 per growth cycle of the crop divided by 162 hm2 and multiplied by the ratio of the growth cycle and the life span of the equipment. Table C.9 lists the weight of the capital, raw material and utility inputs to be delivered to the farm and the energy required for delivery of the inputs. Delivery of outputs The crop weight that is transported from the farm site to the processing (i.e., drying and chipping) site includes the dry crOp weight and the moisture content of the crOp as it is stored at the farm site. Table C.10 336 OOH mmv.om O0.00 mmHuHHHuD mmm.v oom.mh> O0.0mm.H OHOHumumz 3mm em mmm.e em.mH HmuHmmo 080:2 «mm.m emm.moe Hm.mHm.H mmHuHHHuO th.mh omn.vOO.MH om.mmm.hm mHmHumumz 3mm mch wee HmH.ee mm.emH HmeHmeo nmmHm mmO.H «O0.0mH OO.m>m mmHHHHHuD HHH.m~ om~.mHo.m om.mmm.OH mHmHumemz 38m mmmuo mOH meH.mH e~.em HmuHmmo umHmmz mmH OOO.vm HO.mO mmHuHHHuD mmo.m om>.m>m om.Hmh.H mHmHkumz 3mm em mmm.e em.mH HmuHmmo mmcmx an vmm.mm mm.ho mmHuHHHUD mmv.m omm.mmm om.mhm.H mHmHHmumz 3mm em mmm.e em.mH HmuHmmo cuoo mmn OH~.ONH OO.NmN meuHHHuD mmm.mH oom.eHm.m om.mmm.m mHmHumumz 38m mOH meH.mH mm.om HmuHmmo mmHmmHa HmHomo QHBOHm Nenv AmHomO nuzoum many AmHomo :uBOHm NE£\mMV psmcH mono A NHOEHHQIOZV A mHHEImx v Umuuommcmue hum>HHmQ How Hawamuqumm on CD ucmHmz UOHHSqmm hmumcm coHymuuommcmue I'll. OHOQCH may HO >HO>HHOO How OOHHDUOH mmumcm may cam coHpospoum mouo How mesmcH suHHHus mam HmHumume awn .Hmqumo Homnanmz .m.o mHnme 337 lists the weight to be transported and the energy required for transportation as a function of the transportation distance of delivery of the crOps analyzed. Table C.10. Weight to be transported and the energy required for transportation of the crops analyzed Weight to be Energy Required for Transported Transportation CrOp (kg/hm2 growth (MJ primary/hm2 cycle) growth cycle) 50 mia 100 mia 500 mia Alfalfa 42,859 12,450 24,900 124,500 Corn 22,706 6,600 13,190 65,960 Kenaf 22,941 6,660 13,330 66,640 Napier Grass 178,235 51,780 103,550 517,770 Slash Pine 433,134 Wheat 8,547 125,830 251,650 1,258,260 2,480 4,970 24,830 a - Transportation distance for delivery of crOps WMJW", 338 Processing of crops Table C.11 lists the utility requirements for drying and chipping of the crOps analyzed. The capital and raw material energy requirements for drying and chipping are assumed to be negligible. The thermal energy required for the drying operation is assumed to be supplied from natural gas. Table C.11. Utility requirements for drying and chipping of crOps analyzed 2 Utility Require- Crop Yield (tonne/hm growth cycle) ment for Drying and Chipping Dry Wet Drying Chipping Basis Basis (MJ thermal (MI electric hm2 growth hm2 growth cycle) cycle) Alfalfa 36.42 42.85 17,900 3,100 Corn 19.30 22.71 9,500 1,600 Kenaf 19.50 22.94 9,600 1,600 Napier Grass 151.50 178.24 74,600 12,800 Slash Pine 290.20 433.13 398,800 24,500 Wheat 7.35 8.55 3,300 600 ”Iii-11mg Emu“, 339 Application of Input-Output Analysis Table C.12 lists the deflation of equipment cost data and Table C.13 lists the producer's prices and embodied energies of the non-delivered equipment required for crop production. Note that for sales to final demand, the total trade and transportation margins represent 25 per cent of the purchaser's price for farm machinery (sector 4400) (8). The equipment cost representing the embodied energy of the equipment depleted during crOp production is calculated as the total cost of the equipment required for crOp production from 162 hm2 per growth cycle divided by 162 hm2 and multiplied by the ratio of the growth cycle and the life span of the equipment. Table C.l4 lists the energy contents and embodied energies of the non- delivered utilities required for crop production. Table C.15 lists the energy contents and the embodied energies of the delivered utilities required for crOp processing. Note that the trade and transportation margins for sales to final demand for the electric (6801) and natural gas (6802) utilities are zero (8). mfimmfl’ I11|1 .‘S‘Euw Eur; I . 340 Heo.mm oee.H meH.mm 080:3 omm.mem OHH.H mHm.mom mch gmMHm eme.oe oee.H mom.HOH mmmuo umHmmz «OH.HN . oee.H mmm.vm Hmamm eom.em oee.H mmm.em cuoo eme.oe oeH.H mom.HOH mHmmHa AmHoHu rescue mEs\eemHmv HmHuwu suaoum mae\eemHmc ucmEQHDUm mo HOV hMbHM pcmEQqum mo mono OOHHm m.ummm£ousm vanw OOHHm m.ummmsousm mpmp umoo ucmEmHsvm mo COHHMHme .NH.U mHQMB 341 mmmH Hem.om . HmN.eH 0088 news: OHOHN va.Om wmm.Hom cove mch ammHm nvmv va.Om www.mm OOOO mmmuw HmHmmz mmvH va.om mmH.mH OOOO mmcmx mmeH Hem.Om mmH.mH oovv CHOU heme va.Om www.mm oowv MMHOMHO HwHomenuzoum NE; NHOEHHQ,OEV HOV OOOHM HmHomo £u3oum NE£\hmmev Houowm mono mmuwcm OOHUOQEM NHwEHHm Oz OOHHQ O.Hwoscoum OIH coHuODOOHm mono Mom OOHHDOOH pcmEdeqw OOHO>HHOOICOO mo mmHmHmcm OOHOOQEO cam mmOHHQ m.HOO=O0Hm .mH.U mHnme 342 1:55.? , _. ..Infl—nl; Hmeumzu n: I n OHuuomHm OS I m mmm Hmmm.m nHe Home spHoHuuomHm ommm emHm.H meeem HOHm Hmsm 080:3 mmm Hmmm.m nHe Home muHoHuuomHm 0ch «memo emHm.H mesmem HOHm Hess ammHm mHe Hmmm.m aHmH Home muHoHumomHm mmmno memom emHm.H mmmmeH HOHm Hmsm umHmmz mmm Hmam.m aHe Home meHoHuuomHm meem emHm.H memom HOHm Hmsm magma mmm Hmmw.m nHo Home suHoHuuomHm «Hem emHN.H momom HOHm Hana cuoo mHe Hmmm.m nemH Home muHoHuuomHm «HmmH emHm.H moeeHH HOHm Hmsm mmHmmHa HmHomu au3ouw mEa AmHomo au3oum mEa HumeHua a: came as a: O Houomm mpHHHuO mono amumcm amHaanm humEHHm Oz pamucou wmumcm OIH aoHuosaoum mono HOH Emum>m maHmmmOOHQ mumHQmEmc may ma amHHquH mmHuHHHuD amum>HHmOIcoc map mo mmHmumcm pmHaanm cam mpcmuaoo wmumam .VH.U mHame 343 .Eiilfirfifllh Hmeumeu n: I n OHHuomHm OS I m emmm Hmmm.m meow Home mchmHno mmem neOH.H noomm Home ocHsua 080:3 omemm Hmmm.m moomem Home mcHaaHno mch HmeHee BFOH.H noommem Home meHsua ammHm emmee Hmmm.m moommH Home mcHamHso mango «meme eeOH.H nooeee Nome mchua HmHmmz ammo Hmmm.m 82:: Home meHamHno HHmOH eeOH.H noose memo mchuO Hmcmx mmme Hmmm.m mooeH Home mcHamHso mmmoH eeOH.H noomm Nome mchuo euou meomH Hmmm.m mOOHm Home mcHaeHno mammH eHOH.H geomeH Nome mcHsuo mHHmHHa HmHuNO aHBOHm mEa HmHUNO aasonINEa NHOEHHQIOSV HOV O2 O2 V Houomm aOHpmummo mono mmumcm amHaanm .NMmEHHm Oz acmecou mmumcm OIH 111‘ IIIIIIIIGIII ll‘l'l HmaOHumHmmo OCHmmHaO acm OCkua ..m.Hv mcmemooum mouo MOM amHHDUmH mmHuHHHus Umum>HHma mau mo mmHmumcm amHaanm acm muamucom mommam .mH.U mHame APPENDIX D APPENDIX D ENERGY ANALYSIS OF ALCOHOL PRODUCTION FROM CORN General Approach The production of ethanol from corn is basically the same energy supply system analyzed in Appendix C, with the cooking, fermentation and distillation Of the corn, which is harvested, collected and stored at the farmstead, to produce a liquid fuel in place of the drying and chipping of that same corn for the production of a solid fuel. However, the production of a liquid fuel is much more energy intensive than the production Of a solid fuel. Thus, a rigorous energy analysis must be applied to the processing system that converts corn into ethanol. The technology and the components utilized for the production of alcohol are conventional allOwing the straight- forward application of input-output analysis to the material and energy flows of the nameplate processing system as identi- fied through the application of process analysis. The energy subsidy of the corn (as stored on the farmstead) required by the system is taken from the analysis performed in Appendix C. The corn is assumed to be transported 500 miles via for- hire inter—city truck transportation from the farmstead to 344 '1- 345 the alcohol plant and a transportation distance of 500 miles via private inter-city truck transportation is assumed for the delivery of the by—products of the alcohol plant. The transportation distances for the delivery of the required coal to the alcohol plant (via rail transportation) and the delivery of the alcohol to its end-use site (via private inter-city truck transportation) are varied in order to indicate the sensitivity of the system's energy parameters to these transportation distances. Note that a dollar cost for the installation of equipment is reported in the design report describing the alcohol plant and the energy required for these operations is based on the reported cost. The same energy requirement is also estimated from information Obtained from the disag- gregation of energy intensity coefficients for comparison purposes. Definition of Nameplate Processing_System The inputs and outputs of the nameplate processing system are defined by the capital, raw material and utility requirements and the products of the alcohol plant described in a design evaluation performed by the Raphall Katzen Associates (1). The alcohol plant requires inputs of deliv- ered corn, coal, chemicals and capital. The outputs of the plant are 199 proof ethanol, distiller's dark grains, fusel oil and 40 weight per cent aqueous ammonia sulfide solution (all products are non-delivered). 346 Description of Data The data describing the inputs and outputs of the nameplate processing system are contained in a design report Of a grain motor fuel plant assembled by the Raphall Katzen Associates (1). The capital investment is reported as the purchaser's price in 1978 dollars for the components required by the system operations listed in Table D.l purchased as sales to final demand, the required field materials purchased as sales to the new construction industry (sector 1103) and the buildings and structures representing a sub-contracted fee paid to the new construction industry for the construc- tion of the buildings and structures. The installation of components and field materials is reported as the purchaser's price in 1978 dollars for the installation service. The required raw materials are reported as an annual purchaser's price in 1978 dollars and the required utilities are reported as the annual quantities of fuel or electricity consumed. The feedstock requirement is reported as the annual quantity of delivered corn (at a 15 per cent moisture content) processed. Application of Process Analysis Inputs Inputs 1-3, 8-10 Table D.2 lists the purchaser's price of required components and field materials. The installation Of the ‘Ig-m-mr—"Imm' m 347 Table D.l. Definition of Operations required for production of alcohol from corn (1) Section Operation 100 Grain storage 200 Cooking and saccharification 300 Fungal Amylase production a 400 Fermentation g” 500 Distillation f 600 Residue feed processing in 700 Storage and shipping 800 Utilities IIIIIII-IIIIIIIIIIIIIIIIIIIIanEfibrfirifilF. 348 H.O mHama CH amCHmma CoHumHmmo Emumwm I m O.m>m II II II II II II II II momm 0.0mm II II II II II II II II mOmm II II II II II m.H 0.0mm 0.0H II vomm II 0.0mv m.HHH 0.0mm II II II m.m O.mh home II II II 0.0HO II II II II II womv II 0.0HO O.Hw h.mvH II 0.0o m.mm II m.Hm momv II m.OHm O.HN 0.0 H.mm q.om O.HOH O.Hm II Homv II 0.0m 0.00 II II II II II II «OOO II II 0.0H O.mv II II II II m.om «OOO II II II II II II II II 0.0m Home II 0.00m II II II II II II II momw II II O.NO m.mmH II II II II m.mvh Nome 0.00HN II 0.0m H.Ov II II II 0.0H II mOmv II 0.0HOm 0.000H m.wmmm O.HmvH O.HOOH 0.0mw 0.000 II moov 0.0mm II II II II II II II II vOOO O.NHN II II II II II II II II ONOm 0.0mm II II II II II II II II OHOm O.mm II II II II II II II II OOOm mHmHHmumz aHmHm mOOm moon mOOO moom mOOO moom OON mOOH quEmHCqm Hmmem mOH xv mOHHm m.ummmaousm Houomm OIH HHV mHmHumumE OHmHm OCm muamCOQEoo amCHCqmn mo mmOHum m.ummmaousm .N.C mHama 349 components and field materials and the construction of buildings and structures are reported as 11141 x 103 and 3 13478 x 10 $1978 purchaser's price (sector 1103), respectively (1). Inputs 4-5 The feed to the system is freely available solar radiation. Table D.3 and Table D.4 list the annual raw material and utility requirements, respectively. The system is reported to require 543,977 tons/yr. of delivered corn (at a moisture content of 15 per cent) (1). The energies required for delivery of the corn and coal to the alcohol plant are estimated by extending process analysis to the delivery systems and the energy content and subsidy of the corn is estimated by extending process analysis to the crop producing system. Table D.3. Raw material requirements (1) Raw Purchaser's Price I-O Material ($1978/yr) Sector Yeast 316800 2701 Miscellaneous Chemicals 422633 2701 Solvent 7223 2701 Iodine Sterilizing Solution 17028 2701 "PIT-Henna? 4.1-1) 350 Table D.4. Utility requirements Emagy COmamed:fln: Unit Quantity Energy Production I-O Utility Quantity Required (1) Content (2) of Alcohol Sector hmrbfim) (Bayhnnfl bcloglfinflwfl Coal ton 97899 21.3 x 106 2085.2 700 Tramxm Gasoline gal 285120 125075 35.7 3101 Electricity Kwh 65.8 x 106 3413 224.7 6801 Inputs 6-7 Energy required for delivery of the primary (ethanol) and secondary (distiller's dark grains, fusel Oil, ammonia sulfied solution) products is estimated by extending process analysis to the delivery system. There are no waste products reported that require handling facilities not included in the nameplate processing system. Input 11 Data describing the maintenance requirement of the system is not reported. The energy required for maintenance is assumed to be negligible. Outputs Table D.5 lists the energy outputs of the system. 4‘. 351 Table D.5. Energy outputs of alcohol plant Energy Unit Quantity Energy Energy Product Quantity Produced (1) Content (2) Output (unit/yr) (Btu/unit) (x 109 Btu/yr) Alcohol gal 50 x 106 84060 (1) 4203 Distiller's Dark Grains ton 173448 8169 (l) 2834 Fusel Oil gal 224000 149690 (2) 34 Extension of Process Analysis Energy Subsidy and Content of Delivered Corn Table D.6 lists the energy content and energy subsidy of the delivered corn required by the system. Table D.6. Energy content and subsidy of delivered corn (15 per cent moisture content) (7) Energy Energy Subsidy Energy Content Energy Subsidy Quantity Contgnt of of Delivered of Feed to of Feed to . Corn (7) Corn (7) System System Requir ed 6 9 9 (ton/Yr) (x 10 Btu/ton)(Btu4primary (x 10 Btu/yr) (X 10 Btu Bu; ) praanVYr) 543977 12.073 0.278 6567 1824 a-Ehsaion