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Sleetmute Supplement Reconnaissance Study of Energy Requirements & Alternatives 5-1981
OF ENERGY REQUIREMENTS & ALTERNATIVES FOR SLEETMUTE INTERNATIONAL ENGINEERING COMPANY, INC. ‘A MORRISON-KNUDSEN COMPANY ROBERT W. RETHERFORD ASSOCIATES DIVISION BSS Bit tee PrP PP rier ra eee —_ ALASKA POWER AUTHORITY __ SLEETMUTE SUPPLEMENT TO RECONNAISSANCE STUDY OF ENERGY REQUIREMENTS AND ALTERNATIVES FOR BUCKLAND, CHUATHBALUK, CROOKED CREEK HUGHES, KOYUKUK, NIKOLAI, RED DEVIL, RUSSIAN MISSION, SHELDON POINT, SLEETMUTE, STONY RIVER, TAKOTNA AND TELIDA MAY 1981 Prepared by: Robert W. Retherford Associates Arctic Division of International Engineering Co., Inc. Anchorage, Alaska For the State of Alaska Department of Commerce and Economic Development Division of Alaska Power Authority 333 West Fourth Avenue, Suite 31 Anchorage, Alaska 99501 Under Contract No. AS44.56.010 APA 20/T1 This report was prepared by: Robert W. Retherford Associates Arctic Division of International Engineering Company R.W. Retherford, P.E. Frank J. Bettine, E.1.T. James J. Lard, E.I.T. Mark Latour, Economist Illustrations on the front cover were prepared and sketched by Kathryn L. Langman. These illustrations portray several energy resource alternatives investigated for the Thirteen Villages included in this study. APA 20/T2 TABLE OF CONTENTS Section Page 1. Summary and Results 1.1 2. Recommendations 2.1 3. Existing Conditions and Energy Balance 3.1 4. Energy Requirements Forecast 4.1 a. Resource and Technology Assessment 5.1 6. Energy Plans 6.1 APPENDIX A Description of Selected Technologies APA*32C1 SECTION 1 SUMMARY AND RESULTS APA*32C2 SECTION 1 SUMMARY AND RESULTS A. SUMMARY A study was recently conducted under contract number AS44.56.010 for the State of Alaska Department of Commerce and Economic Development, Divi- sion of Alaska Power Authority to determine the energy alternatives for Thirteen Western Alaskan Villages. This study consists of establishing the following: Energy Balance for 1979 Existing Power and Heating Facilities - 1980 Electric Power Requirements to the year 2000 Space Heating Requirement to the year 2000 Potential Energy and Electric Power Resources Evaluation of the Electric Power Resources Recommendations for the development or future studies for the 13 Western Alaskan villages of Buckland, Hughes, Koyukuk, Telida, Nikolai, Takotna, Stony River, Sleetmute, Red Devil, Crooked Creek, Chuathbaluk, Russian Mission and Sheldon Point (See Figure 1.1). The Sleetmute supplement represents a brief summary of the most pertinent facts and findings contained in the original report which relate to the village of Sleetmute. Detailed data concerning the village may be obtained by referring to the original report. Diesel fuels are presently used to satisfy the major percentage of energy demands in the village.’ Emphasis in the study was therefore placed on possible resources and technologies that could replace or at least supple- ment the use of increasingly costly fuel oil. The energy alternatives which were selected for detailed evaluation in the village of Sleetmute include: ! 1) Diesel generation 2) Waste Heat Recovery 3) Binary Cycle generation using wood fuel 4) Passive solar heating 5) Energy conservation 1 See Appendix A for brief description of technologies listed. 1-1 APA34*B1 Nootak River | 1 BUCKLAND / 2 HUGHES / 3 KOYUKUK / 4 RUSSIAN MISSION — ee 5 SHELDON POINT ae “le 6 CHUATHBALUK R- . ws sa sene \ 7 CROOKED CREEK —~—v 8 NIKOLAI 9 RED DEVIL Yalan ©, Tenane Plateou 10 SLEETMUTE 7 11 STONY RIVER yepeaiee 12 TAKOTNA s Minchuming WN Rangy \ 13 TELIDA 12 é Sustina Ry Cobpg, Oiiriet | 7 Talkeem Biter oO ' v . River | 7 Go Mountains " we ow 9 1X 290) a Cp oy oon NS og dts "Ming we) BETHEL o e (ANCHORAGE \ s Tikche av ae 9 7 ¢ vets yo ot Gy a Swf WH of 9»? of YAKUTAT q : 7 U i UNEA! Guilt of Aloska 3 ° . Y, s g CO Ko, Bristol BOY KODIAK IFIG ; c PAC OCEAN : 8 gs ve pve to ¢ § ° 7 0 J 2 FIGURE 1.1 et ALASKA MAP 13 WESTERN VILLAGES SECTION 1 SUMMARY AND RESULTS To obtain a comprehensive understanding of future energy requirements for the village, a control year - 1979 - was established from which all projections have been made. Information related to village history, population and economic conditions, plus information regarding village government, transportation, power and heating facilities, fuel require- ments, etc., was collected to provide the necessary background data to support these projections. B. EVALUATION RESULTS 1. Economics Table 1.1 is a summary of the 20-year economic evaluation performed for the combination of alternatives (i.e., energy plans) selected for detailed study for Sleetmute. This Table lists the accumulated present worth of plan costs and the accumulated present worth of the net benefits derived from non-electrical outputs, where: 1) Plan costs represent the cost for providing electrical generation, and 2) Net benefits represent the savings derived from waste heat capture or surplus hydroelectric energy used for electric heating. a. Twenty Year Evaluation Results Results of the 20-year economic evaluation indicate that the use of diesel with waste heat recovery to be most economical energy plan examined for Sleetmute. The diesel generation plus binary generation with waste heat energy plan averaged approximately 18 percent greater cost than the diesel generation plus waste heat recovery plan for Sleetmute. APA34*B3 vol SLEETMUTE Table 1.1 Accumulated Present Worth of Plan Costs and Benefits ($1,000) Diesel Diesel & & Diesel Binary Cycle Diesel WECS PERIOD & & & & Waste Heat Waste Heat Hydroelectric Waste Heat Cost-Benefit Cost-Benefit Cost-Benefit Cost-Benefit 20-year 1695-162.9 2009-140.1 N/A N/A SECTION 1 SUMMARY AND RESULTS Passive solar and energy conservation have not been economically evaluated in detail and they are, therefore, not listed in Table 1.1. Numerous past studies have shown the value of conservation and passive solar heating. An approximate fifteen percent reduction in fossil fuel requirements due to the implementation of passive solar heating and energy conservation measures has been built into the village Heating Requirement Forecast Tables listed in Section 4. It is assumed that these two methods of reducing usage will be implemented in the village. 2. Environmental and Technical Results of the environmental and technical evaluations are listed in Table 1.2. These results indicate the overall environmental and technical ranking of energy plans selected for detail study for the village of Sleetmute in order of preference to be: 1) diesel electric plus waste heat 2) diesel plus binary cycle generation with waste heat APA34*B5 9-L APA 28P1 Table 1.2 Factor (A) Econo! (B) Envir qQ) (2) (3) (4) (5) (6) (7) (8) Envir (C) Techn Q) (2) (3) TECHNICAL OVERALL R mic (Present Worth) onmental Community Preference Infrastructure Timing Air Quality Water Quality Fish and Wildlife Land Use Terrestrial Impacts TOTAL onmental Ranking ical Safety Reliability Availability TOTAL RANKING ANKING EVALUATION MATRIX Diesel Electric + Waste Heat Inner Pew wo nm uo ra ole win H Diesel + Local Hydro w/wo Electric Heat Diesel + Binary Generation Coal and/or Wood With Waste Heat |p eR RON OS w ~ lo wn 12 Diesel + Waste Heat Supplemental Wind Generation SECTION 2 RECOMMENDATIONS APA34*B6 SECTION 2 RECOMMENDATIONS A. GENERAL Analysis of the 20-year economic, technical and environmental evaluations indicate the two most promising energy plans for the village of Sleetmute in order of preference to be: 1) Continued use of diesel generation supplemented with waste heat recovery, 2) diesel plus binary cycle generation supplemented with waste heat recovery. B. RECOMMENDED PLAN - Diesel Generation Supplemented with Waste Heat Recovery. The 20-year economic, technical and environmental evaluation indicate that diesel generation with waste heat recovery will provide the most satisfactory method of providing electric energy for the village of Sleetmute. It is recommended, therefore, that a study be conducted to determine the feasibility of utilizing waste heat in the village of Sleetmute. Such a study should include a definitive review of the following items: 1) availability of waste heat 2) transportation of waste heat 3) end use of waste heat C. FIRST ALTERNATIVE PLAN - Diesel Plus Binary Cycle Generation Supple- mented With Waste Heat Recovery. The first alternative plan, as listed above, is diesel plus binary cycle generation with waste heat recovery. This plan averages approximately 18 percent greater costs than the recommended plan (20-year economic evalu- ation). Because the uncertainties in the costs associated with this alternative, such as the cost of wood fuel, equipment cost, etc., which 2-1 APA34*B7 SECTION 2 RECOMMENDATIONS can not at present be as precisely determined as for the recommended plan, it is conceivable that this alternative could be cost competitive with the alternative plan (i.e., diesel generation plus waste heat recovery). Because binary cycle generation is viewed as one of the few potentially viable energy alternatives, suitable for future use in remote Alaska villages such as Sleetmute, it is recommended that the feasibility of binary cycle generation in Alaska be further investigated in regard to: 1) Equipment availability 2) Technical feasibility 3) Economic aspects 4) Environmental aspects 5) Constraints Binary cycle generation equipment in unit sizes suitable for village appli- cation is, however, not expected to be available until the late 1980's. D. COSTS FOR FURTHER STUDY Approximate costs for determining of feasibility of the two most attractive energy resources for the village of Sleetmute are: e Waste heat recovery - approximately $2500 e Binary cycle generation - approximately $2,000,000 which would include the cost of constructing and operating a demonstration plant in Alaska. E. CONSERVATION MEASURES For the village to stabilize and hopefully reduce the local cost of energy immediate short term conservation measures could provide the most rapid results. These conservation measures, which include added insulation, double glazing or solar film, arctic entrances, weather stripping, etc., can reduce current non-transportation fuel use on the order of 15 percent over the 20-year period of this study. 2-2 SECTION 3 EXISTING CONDITIONS AND ENERGY BALANCE APA34*B9 SECTION 3 EXISTING CONDITIONS AND ENERGY BALANCE A. INTRODUCTION To establish a base and understanding of energy use in the village, an energy balance has been compiled for the year 1979. Input energy forms are diesel, wood, propane, blazo, gasoline, and aviation gasoline. Energy used in the village has been listed both by end use category (i.e., heating, transportation, and quantities used for electrical generation) and by consumer category to include residential, small commercial, public buildings, and large users (school), in the following table (Table numbered as in original report). To provide background data, information related to village history, demographic and economic conditions plus information regarding village government, transportation, power and heating facilities is included. a. | GENERAL BACKGROUND INFORMATION History: The village of Sleetmute is located on the east bank of the Kuskokwim River; 1.5 miles north of its confluence with the Holitna River and 78 miles east of Aniak. "Sleetmute", meaning "whetstone people" was named for the nearby shale deposits. The village was founded by local Ingalik Indians. The Russian developed a trading post near the present village site in the early 1830's. The trading post was later moved, however, from Sleetmute to a site about 100 miles down the Kuskokwim River. Pursuant to the Alaska Native Claims Settlement Act of 1971, the Sleetmute Village Corporation was entitled to select 92,160 acres of Federal lands. When the 3-1 APA34*B10 APA34*B11 SECTION 3 EXISTING CONDITIONS AND ENERGY BALANCE Sleetmute Corporation merged with 9 other Middle Kuskokwim Village Corporations, this entitlement passed to The Kuskokwim Corporation (TKC) for consolidated ownership and management. Calista Corporation is the regional corporation. Population: The earliest recorded population data for the site were obtained in 1907 when there were 150 residents in the village. By 1939, the population had declined 42 percent to 86 residents. The 1950 census figures show a resurgence to a population of 120, which remained stable through the 1960 census. The 1970 census shows a 12 percent decline to a total of 109. Sleetmute's population was 87 percent Native in 1970. A local esti- mate of population counted 109 residents in 1979 (both sides of river). In 1979, the average number of members per household in the community was 5.4 persons. Economy: Most cash employment in Sleetmute is derived from public employment. The Kuspuk School District employs ten people in full-time jobs during the school year. The BLM employs approximately 16 residents each summer as fire fighters. Other residents work in canneries outside the area during the fishing season. There is no commercial fishing activity within Sleetmute. Additionally there is a family owned and operated flying service located across the river from the village. Additional income is derived from trapping and the sale of furs and cash subsistence programs. Approximately 60 percent of the village's food is derived from subsistence fishing, hunting and gathering. In addition to salmon caught during the summer, numerous 3-2 SECTION 3 EXISTING CONDITIONS AND EXISTING BALANCE other species of fish are taken by area residents. The area residents hunt moose, bear, ptarmigan, waterfowl, porcupine and rabbit. In the fall, families harvest a variety of berries. Government: Sleetmute is not incorporated as a munici- pality under State law and, there is no borough govern- - ment within the region. Sleetmute's Native population APA34*B12 is represented by a 5-member traditional council. A 7-member village council represents the residents of Sleetmute. ENERGY BALANCE (1979) Residential and small commercial consumer heating requirements account for approximately 51.7 percent of the energy needs of the village. Transportation results in an additional 30.2 percent and electric generation 18.1 percent. Graph 3.10 illustrates by consumer category the type and percentages of energy forms used in the village. Table 3.10 tabularizes this data in additional detail. EXISTING POWER AND HEATING FACILITIES Electric Power: No centralized power system exists in the village, but electrification of the village is scheduled for the summer of 1981. The Kuspuk School District maintains and operates the school generating facilities in Sleetmute (2 - 50 kW units) which supply power to the school and to numerous public buildings in APA34*B13 © SECTION 3 EXISTING CONDITIONS AND ENERGY BALANCE the village. A combination retail outlet and flying service, located on the opposite side of the river, maintains and operates a small generator for its own use. Heating: Heating requirements for residential and small commercial consumers are satisfied primarily with wood and supplemented with fuel oil. Average residential requirements for heat are 7.7 cords of wood per year and 230 gallons of fuel oi]. Public buildings and the school building facilities use fuel oi] for heating purposes. Fuel Storage: Diesel, bulk fuel oil] storage capacity in the community is approximately 33,000 gallons (reference 27). 3-4 GRAPH 3.10 1979 ENERGY BALANCE SLEETMUTE EFFICIENCIES ASSUMED: LEGEND | HEATING — 75% GY — RESIDENTIAL TRANSPORTATION — 25% GG) — SMALL COMMERCIAL ELECTRICAL GENERATION — 25% (>) — PuBLic BUILDINGS ( — LARGE USERS (SCHOOL) () — WASTE HEAT TOTAL ENERGY (100%) HEATING (51.7%) BLAZO — 1.4% PROPANE— 0.5% WOOD — 23.2% DIESEL — 26.6% memAC I Mcaa%6 TRANSPORTATION (30.2%) i—1___ GASOLINE + AV GAS 30.2% ELECTRICAL GENERATION (18.1%) tt DIESEL 18.1% MA AES AMAA 0 2000 4000 6000 8000 10,000 12,000 14,000 16,000 18,000 BTU x 10° | 20,000 9-€ apa28: a5 ENERGY BALANCE - 1979 SLEETMUTE Table 3.10 CONSUMER ENERGY FORM CONSUMED HEATING TRANSPORTATION ELECTRICAL DIESEL wood PROPANE BLAZO GASOLINE AV GAL DIESEL TOTAL GAL CORDS POUNDS. GAL GAL GAL GAL 10° Btu TYPE NO. 10® Btu 10® Btu 10* Btu 10® Btu 10® Btu 10® Btu 10® Btu % of Total Residential 24 5,500 184 2,000 1,500 13,200 1,800 - 6,022 759 3,128 39 191 1,676 229 44.7 Smal] Commercial 2 3,000 - - - 8,000! 9,000! 3,070 2,997 414 1,016 1,143 424 22.3 Public Buildings 3 1,650 - - - - - 3,600 725 228 497 5.4 Large User (school) 1 ( 15,770 “ 1,200 - - - 11,000 3,717 2,176 23 1,518 4 27.6 _ _ Total 30 25,9 184 3,200 1,500 21,200 10,800 7,670 13,461 ,b77 3,128 62 191 2,692 1,372 2,439 % of Total Btu 26.6 23.2 0.5 1.4 20.0 10.2 18.1 100 Waste Heat Ly bd 10° Btu 894 782 16 48 2,019 1,029 1H 1,829 6,617 % of Total 6.6 5.8 o1 0.4 15.0 7.6 13.6 49.1 1 Rental outlet and flying service Assumed Efficiency: Heating - 75% Transportation - 25% S41 Electric Generation - 25% ( SECTION 4 ENERGY REQUIREMENTS FORECAST APA34*B15 SECTION 4 ENERGY REQUIREMENTS FORECAST A. INTRODUCTION The following paragraphs and tables outline the planned capital projects, economic activities forecast, and energy end use forecasts for the village of Sleetmute.! 1 Tables numbered as in original report. 4-1 APA34*B16 APA 22-A:J1 SECTION 4 ENERGY REQUIREMENTS FORECAST 10. Sleetmute (a) Planned Capital Projects and Economic Activity forecast Planned Capital Projects: Scheduled developments - School classroom addition Electrification Airport improvements Potential developments - Timber harvest Peat harvest Farewell coal field 0i1 and gas exploration Economic Activity Forecast: Sleetmute could benefit from timber harvest, peat harvest, development of the Farewell coal field and possible oi] and gas exploration in areas along the Kuskokwim. Major developments of these activities are not expected, however, until the late 1980's or early 1990's. No immediate increase jn economic activity is expected, however, in the near future. (b) Population Forecast - Sleetmute The population forecast is shown in the following Table 4.10 Table 4.10 Year 1970 1979 1982 1985 1990 2000 Population 109 109 112 116 122 134 # Residences - 24 25 26 29 34 # Small commercial - 2 2 2 2 2 # Public users - 3 3 3 4 6 # Large users - 1 1 1 1 1 Population growth rate - 1% 4-2 apa22:a5 C. End Use Forecast The end uses of energy are shown in the following Tables 4.10a, 4.10b, 4.10c. Table 4.10a SLEETMUTE ELECTRIC POWER REQUIREMENTS? 1979 1982 1985 1990 2000 Population 109 112 116 122 134 (1) Number of residential consumers - 20 23 26 : 34 (2) Average kWh/mo/consumer - 133 160 220 415 (3) MWh/year residential consumers (2) x (1) x 12 + 1000 - 31.9 44.2 68.6 169.3 (4) Number of small commer- cial consumers - 2 2 2 4 (5) Average kWh/mo/consumer - 848 968 1,205 1,872 (6) MWh/year small commer / cial consumer a - ~ (4) x (5) x 12 + 1000 - 20.4 (332 28.9 \ 89.7 (7) Number of public consumers 3 3 a} 4 6 | wane kWh/mo/consumer _ 850 970 1,107 1,379 2,142 \/ (9) MWh/year public consumer (7) x (8) x 12 + 1000 30.6 34.9 39.9 66.2 154.2 (10) Large (LP) consumer 1 1 1 1 1 (school) (11) Average kWh/mo/LP 7,800 9,400 3 9,686 10,180 11,245 / consumer? Jaz) MWh/year LP's (10) x (11) x 12 + 1000 93.6 112.8 116.2 122.2 135.1 Jax System MWh/year (3)+(6)+(9)+(12) 124.2 200.0 223.5, 285.9 548.3 (14) System load factor 0.6 0.45 0.45 0.45 0.50 (15) System demand kW (13)+8760+(14)x1000 24 51 57 73 125 1 Electrification scheduled for summer 1981 2 School at 1% growth rate 3 Addition of new school classroom 4-3 apa22:c5 Table 4.10b SLEETMUTE HEATING REQUIREMENTS? RESIDENTIAL CONSUMERS 1979 1982 1985 1990 2000 (1) Population 109 112 116 122 134 (2) Number of resi- dential users 24 25 26 29 34 (3) Diesel - Average gal/mo/residence (6)+(2)+12 19 19 19 18 16 (4) Propane - Average 1bs/mo/res idence (7)+(2)+12 7 7 10 19 35 (5) Wood - Average cords/mo/res idence (8)+(2)+12 0.64 0.64 0.64 0.61 0.55 (6) Diesel Gals 5,500 5,730 5,960 6,320 6,710 Btu x 10° 759 791 822 872 926 (7) Propane _ Lbs 2,000 2,080 3,170 6,715 14, 260 Btu x 10° _ 39 41 62 131 278 (8) Wood _ Cords 184 192 199 211 224 Btu x 10° 3,128 3,264 3,383 3,587 3,808 (9) Total Btu x 106 €6)+(7)+(8) 3,926 4,095 4,267 4,590 5,012 (10) Annual per capita consumption Btu x 106 (9)+(1) 36.0 36.6 36.8 37.6 37.4 Assumes a one percent per year decrease in fossil fuel requirements beginning in 1986 due to implementation of passive solar heating and technical improve- ments in both building design and heating equipment. 4-4 (11) (12) (13) (14) (15) (16) (17) (18) (19) apa22-A:R9 SLEETMUTE HEATING REQUIREMENTS?! OTHER CONSUMERS Table 4.10c 1979 Small Commercial 2 user Diesel 3000 Gals/Btu x 10° ~ 414 Public Buildings user 3 Diesel Gals 1650 Btu x 10° 228 Large users (school) 1 Diesel equivalent (diesel + wood) Gals 15,770 Btu x 10° 2,1/6 Propane __1bs 1200 Btu x 10° 23 Subtotal Btu x 10 (16)+(17) 2199 Total Btu x 106 (9)+(12)+(14)+(18) 6,767 1982 1985 1990 2000 2 2 2 4 3000 3000 2853 3056 414 414 394 422 3 3 4 6 1650 1650 2639 4327 228 228 364 597 1 1 iu 1 19,0042 19,004 18,073 16 , 362 2,622 2,622 2,494 2,258 1200 1200 1141 1033 23 23 22 20 2645 2645 2516 2278 7,382 7,554 7,864 8,309 Assumes a one percent per year decrease in fossil fuel requirements begin- ning in 1986 due to implementation of passive solar heating and technical improvements in both building design and heating equipment. New classroom addition. 4-5 SECTION 5 RESOURCE AND TECHNOLOGY ASSESSMENT APA34*B17 SECTION 5 RESOURCE AND RECHNOLOGY ASSESSMENT JA. ENERGY RESOURCE ASSESSMENT The energy resources which are determined to be available for the village of Sleetmute are summarized in the following table. Information concerning approximate quantity, quality, availability, cost, source of data and important comments is included. The energy resources specif- ically addressed include diesel generation, wind, hydroelectric potential, waste heat utilization, timber and coal. While passive solar heating and energy conservation are not specifically addressed in the table, it is assumed these two energy conservation measures will be implemented in the village. Energy resources which are not available for use in Sleetmute and are therefore not addressed include geothermal, peat, solid waste, oil and gas and tidal power. 5-1 APA34*B19 erg APA22-A S9 Table 5.10 ENERGY RESOURCE Diesel fuel Wood fuel Coal fuel Waste Heat! Recovery Hydroelectric Potential Wind potential LOCATION Major supplier Bethel Middle Kuskokwim Healy, Alaska N/A ENERGY RESOURCE ASSESSMENT QUANTITY/AVAILABILITY 167x10® cu ft late 1980's Late 1980"s 30% of fuel used for electrical generation; upon installation of new power plant. N/A ' Assumes $1.46/gal diesel fuel cost 0.45 load factor < > saving per million Btu recovered. SLEETMUTE QUALITY #2 diesel 138,000 Btu/gal 14.6x10® Btu/cord 8500 Btu/1b 17x10® Btu/ton Recoverable heat 41,400 Btu/gal diesel equivalent N/A 6.8 mph average annual wind speed. SOURCE OF COST, DATA $1.46/ga) United $10.59/10® Btu Transportation Bethel. $92/cord Appendix G $6.30/10® Btu $110/ton Appendix H $6.47/10® Btu $450/kW installed Appendix D <$5.21/10° Btu> diesel fuel displaced N/A Reference #38 - Regional Profiles COMMENTS Delivered cost at village Delivered cost at village. Delivered cost at village. Cost assume heat delivery within 100 ft radius of plant. Availability varies with generator loading. Maintenance at $11/kW/yr. Average annual wind speed insufficient for wind generation. SECTION 6 ENERGY PLANS APA34*B20 SECTION 6 ENERGY PLANS A. INTRODUCTION The approach to the energy plans formulated for the village of Sleetmute is explained in this section. Each plan is formulated to meet the forecasted electrical energy requirements of the village plus addi- tional related requirements, such as space heating, where appropriate. A base case plan using diesel generation is formulated for the village. This plan is used as the "control case" to determine the advantage or disadvantage of other alternatives as compared to diesel generation. Future village diesel generation additions assume that the local school, which has sufficient installed generation capacity, will provide its “own back-up capability. The school will, however, rely on the central- ized village power plant for their primary supply of electrical power and energy. A wood-fired binary cycle generation option is presented for the village of Sleetmute. It is assumed the wood required for fuel would be supplied from timber harvested along the Kuskokwim River and its tributaries. Diesel fuel oil-fired binary cycle generation is also possible, but provides no significant cost or technical advantage over diesel engine powered generation. Fuel oil-fired binary cycle generation is, therefore, not included in the formulated energy plan for the village. A waste heat capture analysis is included with all options that use fossil fuels for electrical generation (i.e., diesel generation employing engine jacket water cooling, and binary cycle generation) 6-1 APA34*B22 SECTION 6 ENERGY PLANS a. Base Case Plan 1) Plan components - diesel and waste heat recovery 2) Timing of system additions - Diesel - 1981 - 60 kW + 75 kW; 1991 - 100 kW Waste heat equipment - 1983 - 75 kW; 1991 - 100 kW 3) Plan description - This plan assumes the continued use of diesel driven generators throughout the study and the implementation of waste heat recovery. b. Alternative Plan A 1) 2) 3) APA 32/A18 Plan components - diesel and binary cycle generation using wood fuel and waste heat recovery. Timing of additions - Diesel - 1981 - 60 kW + 75 kW Binary cycle - 1989 - 150 kW Waste heat equipment - 1983 - 75 kW, 1989 - 150 kW Plan description - This plan assumes construction of wood-fired binary cycle generation facilities in the late 1980's as a replacement for diesel genera- tion’and the implementation of waste heat recovery. APPENDIX A DESCRIPTION OF SELECTED TECHNOLOGIES APA34*C21 A.1 DIESEL a. General Description 1) Thermodynamic and engineering processes involved In the diesel engine, air is compressed in a cylinder to a _ high pressure. Fuel oi] is injected into the compressed air, 2) APA*32C35 which is at a temperature above the fuel ignition point, and the fuel burns, converting thermal energy to mechanical energy by driving a piston. Pistons drive a shaft which in turn drives the generator. Current and future availability Diesel engines driving electrical generators are one of the most efficient simple cycle converters of chemical energy (fuel) to electrical energy. Although the diesel cycle in theory will burn any combustible matter, the practical fact of the matter is that these engines burn only high grade liquid petroleum or gas, except for multi-thousand horsepower engines which can burn heated residual oi]. Diesel generating units are usually built as an integral whole and mounted on skids for installation at their place of use. A.2 BINARY CYCLE FOR ELECTRICAL GENERATION a. General Description 1) 2) APA*32C36 Thermodynamic and engineering processes involved In the binary conversion process, a heated primary fluid of insufficient quality for direct use in electrical production passes through a heat exchanger to transfer heat to a working fluid. The working fluid has a lower boiling point than water and is vaporized jin the heat exchanger. The vaporized working fluid then expands through a turbine or cylinder piston arrange- ment is condensed, and returns to the heat exchanger. The primary fluid is returned to its heat source following heat exchange. Current and future availability Current commercial availability is restricted to unit sizes in excess of village power requirements as determined in this study. Binary cycle generation equipment in unit sizes suit- able for village application is not expected to be available until the late 1980's A-2 A.3 HYDROELECTRIC GENERATION a. General Description APA*32C37 Thermodynamic and engineering processes involved In the hydroelectric power development, flowing water is directed into a hydraulic turbine where the energy in the water is used to turn a shaft, which in turn drives a gener- ator. In their action, turbines involve a continuous trans- formation of the potential and/or kinetic energy of the water into usable mechanical energy at the shaft. Water stored at rest at an elevation above the level of the turbine (head) possesses potential energy; when flowing, the water possesses kinetic energy as a function of its velocity. The return of the used water to the higher elevation necessary for funct- joning of the hydroelectric machinery is powered by the sun to complete the cycle - a direct, natural process using solar energy. The ability to store water at a useful elevation makes this energy supply predictable and dependable. Current and future availability Hydroelectric developments in the United States, as of January 1978, totaled 59 million kilowatts, producing an estimated average annual output of 276 billion kilowatt hours according to the U.S. Department of Energy (DOE). Hydropower provides about 10% of Alaska's electric energy needs. Developments range in size from over a million kilowatts down to just a few kilowatts of installed capacity. Hydropower is a time proven method of generation that offers unique advantages. Fuel cost, a major contributor to thermal plant operating costs, is eliminated. A-3 A.4 WIND ENERGY CONVERSION SYSTEMS (WECS) a. General Description 1) 2) APA*32C38 Thermodynamic and engineering processes involved The thermodynamic process involved stems from the sun, the primary energy source which produces the wind. This wind energy cannot be stored, is intermittent, somewhat unpredict- able and thereby undependable. The process then relies on wind flow over an air foil assembly to create differential pressures along the air foil. This differential pressure results in rotation of the assembly around a fixed axis to which it is attached. Power from the wind is transmitted through the connection shaft and accompanying gear box to an electrical generator. Three types of generators are presently in use with wind energy systems. These are the DC generator, the AC induction generator and the AC synchronous generator. Of the three types, the AC induction generator is the most widely used because of its simplicity and low cost. An induction generator is not a stand- alone generator and must be connected to an external power system of relatively constant frequency and voltage to operate properly. Current and future availability Availability of the wind at useful velocities require long term records to estimate the potential energy. Lesser records provide less credible estimates Availability of WECS machinery in small size units in the 1.5 kW to 20 kW range is good. Large units in the 100-200 kW range are currently undergoing tests in both the government and private sector and should be available in the near future. Demonstrations of multi-megawatt sizes are in process. A-4 A.5 DIESEL WASTE HEAT RECOVERY a. General Description 1) 2) APA*32C39 Thermodynamic and engineering processes involved The present use of fossil fuels (coal, gas, oi1) in Alaska (as elsewhere) to produce more useful forms of energy (heat, electricity, motive power) is less than 100 percent efficient. For example, if a machine burns a certain quantity of fossil fuel and produces useful output (shaft horsepower, electrical energy, steam, useful hot water or air for space heating) equivalent to 30% of the fuel burned, the energy represented by the remaining 70% of the fuel will appear as unused or "waste" heat. Such heat most often appears as hot exhaust gas, tepid to warm water (65°F-180°F), hot air from cooling radiators, or direct radiation from the machine. Diesel waste heat can be recovered from engine cooling water and exhaust, or either source separately. The waste heat is typically transferred to a water-glycol circulating system in Alaskan applications. The heated circulating fluid can be used for space, water, or process heating where temperatures of the waste hear are suitable. Current and future availability Recovery of diesel waste heat in Alaska is growing as a result of sharp increases in diesel fuel cost. Recovery of jacket water heat only is most common in Alaska. Diesel waste heat availability is directly related to the location and operating cycles of the engine installations. A-5 A.6 PASSIVE SOLAR HEATING a. General Description Passive solar heating makes use of solar energy (sunlight) through energy efficient design (i.e. south facing windows, shutters, added insulation) but without the aid of any mechanical or electrical inputs. Space heating is the most common application of passive solar heating. Because such solar heating is available only when the sun shines its availability is intermittent (day-night cycles) and variable (winter-summer-cloudy-clear). A-6 APA*32C40 A.7 CONSERVATION a. General Description 1) 2) APA*32C41 Thermodynamic and engineering processes involved Conservation measures considered here are mainly classified as "passive". Passive measures are intended to conserve energy with- out any further electrical, thermal, or mechanical energy input. Typical passive measures are insulation, double glazing or solar film, arctic entrances and weather stripping. Energy conservation characteristics of some passive measures degrade with time, which must be considered in the overall evaluation of their effectiveness for an intended life cycle. Other conservation measures includes improvement in efficiency of utilization devices (such as motors) and "doing without" energy by disciplines (turning off lights, turning down thermostats). Current and future availability Materials and schemes to implement passive measures are commer- cially available and increasing in use all over the United States due to the rapidly escalating cost of energy. A-7 PROPERTY OF: Alaska Power Authority 334 W. 5th Ave. Anchorage, Alaska 99501