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HomeMy WebLinkAboutTakotna Reconnaissance Study of Energy Requirements & Alternatives 1981VIL-R 004 Takotna 2 OF i -ENERGY REQUIREMENTS & ALTERNATIVES z &§ FOR 582 TAKOTNA a2 6 PROPERTY GF: & 6 & m oO > | = a 8 = uf a INTERNATIONAL ENGINEERING COMPANY, INC. A MORRISON-KNUDSEN COMPANY ROBERT W. RETHERFORD ASSOCIATES DIVISION pre ALASKA POWER AUTHORITY = TAKOTNA 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.I.T. James J. Lard, E.1.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 Section an no FW DY APPENDIX A APA*32C1 TABLE OF CONTENTS Summary and Results Recommendations Existing Conditions and Energy Balance Energy Requirements Forecast Resource and Technology Assessment Energy Plans Description of Selected Technologies Page 1.1 2.1 3.1 4.1 5.1 6.1 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 Takotna supplement represents a brief summary of the most pertinent facts and findings contained in the original report which relate to the village of Takotna. 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 oi]. The energy alternatives which were selected for detailed evaluation in the village of Takotna include: ? 1) Diesel generation 2) Waste Heat Recovery 3) Binary Cycle generation using wood fuel 4) Hydroelectric generation 5) Passive solar heating 6) Energy conservation 1 See Appendix A for brief description of technologies listed. 1-1 APA32*J1 BUCKLAND HUGHES KOYUKUK RUSSIAN MISSION SHELDON POINT. CHUATHBALUK CROOKED CREEK NIKOLAI RED DEVIL SLEETMUTE STONY RIVER TAKOTNA TELIDA @SnNOWRWH = ° Yukon - Tonone Piot FAIRBANKS 3 — n= w& YAKUTAT Guilt of Aloske Bristot 89 KODIAK pACIFIC FIGURE 1.1 S . 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 L. Economics Table 1.1 is a summary of the 20 and 50-year economic evaluation per- formed for the combination of alternatives (i.e., energy plans) selected for detailed study for Takotna. 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 Takotna. The diesel generation plus binary generation with waste heat energy plan averaged approximately 9 percent greater cost than the diesel generation plus waste heat recovery plan for Takotna. This small variation in cost between the two energy plans represents an insignificant difference in a reconnaissance level study, where costs cannot be precisely determined, and should not be construed to indicate a definite cost advantage of one plan over another. i=3 APA32*J3 vol TAKOTNA Table 1.1 Accumulated Present Worth of Plan Costs and Benefits ($1,000) Diesel Diesel & & Diesel Binary Cycle Diesel a WECS PERIOD & & & & Waste Heat Waste Heat Hydroelectric Waste Heat Cost-Benefit Cost-Benefit Cost-Benefit Cost-Benefit 20-year 2064-202.8 2250-186.1 9805-149.9 N/A 50-year 5169-737.9 20556-168.7 N/A 4883-685.0 SECTION 1 SUMMARY AND RESULTS Hydroelectric generation is found to be the most expensive method of providing electrical energy for Takotna. 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. b. Fifty Year Evaluation Results: The results of the 50-year economic evaluation performed for the village of Takotna confirms hydroelectric generation as the most expensive method of providing electrical energy. The high cost of developing the potent- jal hydroelectric site located on Ganes Creek west of Takotna makes the use of hydroelectric generation economically unrealistic. The results of the 50-year evaluation has, however, altered the findings of the 20-year evaluation. The extended evaluation indicates the diesel generation plus binary cycle generation with waste heat energy plan will provide the most economical method of supplying electrical energy for these two villages. Zs 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 Takotna, in order of preference to be: 1) diesel electric plus waste heat 2) diesel plus hydroelectric generation 3) diesel plus binary cycle generation with waste heat 1=5 9-L APA 28N1 Table 1.2 Factor (A) Econo mic (Present Worth) (B) Environmental QQ) (2) (3) (4) (5) (6) 7) (8) Community Preference Infrastructure Timing Air Quality Water Quality Fish and Wildlife Land Use Terrestrial Impacts TOTAL Environmental Ranking (C) Techn QQ) (2) (3) ical Safety Reliability Availability TOTAL TECHNICAL RANKING OVERALL RANKING Diesel Electric + Waste Heat POR TOnCIeencolns N o for eons Bat EVALUATION MATRIX Diesel + Local Hydro w/wo Electric Heat lao wHrrouep yp wo F-2 Diesel + Diesel + Waste Heat Binary Generation Supplemental Coal and/or Wood Wind With Waste Heat Generation js eee anaes 1 w ™~ 1 lo in 1 ' 12 - SECTION 2 RECOMMENDATIONS APA32*J7 SECTION 2 RECOMMENDATIONS A. GENERAL Analysis of the 20-year and 50-year economic, technical and environ- mental evaluations indicate the two most promising energy plans for the village of Takotna 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 and 50-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 Takotna. It is recommended, therefore, that a study be conducted to determine the feasibility of utilizing waste heat in the village of Takotna. 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 9 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 APA32*J8 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 Takotna, 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 Takotna 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. a2 APA32*J9 SECTION 3 EXISTING CONDITIONS AND ENERGY BALANCE APA32*J10 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: Takotna is located on the north bank of the Takotna River 14 air miles west of McGrath. In the past, Takotna served as a riverboat landing and supply point for the Innoko placer district. The name of the community is derived from the Takotna River. Doyon Limited is the regional corporation of the area. Population: A 1930 estimate listed the population of Takotna at 65 residents. A 1978 estimate put the population at 50, with 17 residences. The 1980 estimate showed a population of 87, with 22 residences. The average number of residence per household in the community is 4.0 persons. 3-1 APA32*%J11 APA32*%J12 SECTION 3 EXISTING CONDITIONS AND ENERGY BALANCE Economy: Permanent employment in the village is limited to government services, the regional school district and support services. A small number of civilians who are employed at Tatalina AFS also live in Takotna. The economy of Takotna is also dependent on the seasonal gold mining operations which exist in the mountains north and west of the community. Income from these enterprises is supplemented by public assistance payments and residents' subsistence activities. Residents hunt moose, bear, rabbit, game birds and waterfowl. Income is also derived from trapping and the sale of furs. During the summer months, most residents fish for salmon. In the fall, families harvest numerous varieties of berries. Transportation: Takotna's location affords easy access by boat and river barge during the summer months. Shipments of fuel and bulk supplies are delivered by barge lines to the community during the summer. Takotna is surrounded by approximately 100 miles of road which were constructed to support mining operations in the area. The community is linked to its nearest neighbor, Tatalina Air Force Station by 9 miles of road, which is maintained year around. Several vehicles exist in the community and are used extensively for transportation. Additional transportation is accomplished in the summer by boat and in winter with snowmachines. A gravel airstrip provides access by aircraft. Passengers, small cargo items and mail are primarily delivered by air. 322 APA32*J13 SECTION 3 EXISTING CONDITIONS AND ENERGY BALANCE ENERGY BALANCE (1979) The heating requirements in Takotna account for approxi- mately 58.4 percent of the energy used in the village. Transportation accounts for 21.0 percent of the use and electrical generation for an additional 20.6 percent. Graph 3.12 illustrates by consumer category the types and percentages of energy forms used in the village. Table 3.12 tabularizes this data in additional detail. EXISTING POWER AND HEATING FACILITIES Electric Power: Construction of centralized generation facilities in Takotna was completed in November of 1979. Installed generation units consist of a 40-kW and a 20-kW unit. All consumer categories, including public buildings and large power consumers (school), are being supplied by the utility. The distribution system consists of overhead triplex construction operating at 240/120 volts. Heating: The majority of the residential and small commercial consumers in Takotna heat with wood supple- mented with fuel oi]. Public buildings and the school facilities are primarily heated with fuel oil. Resi- dential consumers average approximately 7.2 cords of wood per year supplemented with 100 gallons of fuel oi] per year. Fuel Storage: Diesel, bulk fuel oi] storage capacity in the community (village + school) at about 30,000 gallons (estimated during village visit). GRAPH 3.12 1979 ENERGY BALANCE TAKOTNA EFFICIENCIES ASSUMED: LEGEND HEATING — 75% (GG) — RESIDENTIAL TRANSPORTATION — 25% (GG — SMALL COMMERCIAL ELECTRICAL GENERATION — 25% (7 — PUBLIC BUILDINGS () —_ LARGE USERS (SCHOOL) (GE) — «WASTE HEAT TOTAL ENERGY (100%) 1.6% HEATING (58.4%) BLAZO. — 1.0% PROPANE— 2.5% WOOD — 26.2% DIESEL — 28.7% TOTAL — 58.4% TRANSPORTATION (21.0%) ———— Sener ELECTRICAL GENERATION (20.6%) 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10,000 apa28: a9 ENERGY BALANCE - 1979 TAKOTNA Table 3.12 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 To® Btu 10® Btu 10° Btu 10° Btu 10® Btu 10® Btu % of Total Residential 20 2,000 144 10,700 750 15,400 = = 4,984 276 2,448 209 95 1,956 53.4 Small Commercial 2 1,100 = = = = = - 152 152 1 Public Buildings 3 1,550 - - - - - 3,600 711 214 497 7.6 Large User (school) 1 14,770 = 1,200 = = = 10,300 3,482 2,038 23 1,421 37.4 Total 26 19,420 144 11,900 750 15,400 - 13,900 2,680 2,448 232 95 1,956 1,918 9,329 % of Total Btu 28.7 26.2 2.5 1.0 21.0 = 20.6 100 Waste Heat 10° Btu 670 612 _58 _24 1,467 1,439 4,270 % of total Btu Reo 6.6 0.6 0.3 1527 15.4 45.8 Assumed Efficiency: Heating - 75% Transportation ~ 25% Electric Generation - 25% SECTION 4 ENERGY REQUIREMENTS FORECAST APA32*J14 SECTION 4 ENERGY REQUIREMENTS FORECAST INTRODUCTION The following paragraphs and tables outline the planned capital projects, economic activities forecast, and energy end use forecasts for the village of Takotna.? 1 Tables numbered as in original report. 4-1 APA32*J15 APA 22-A L1 SECTION 4 12. Takotna (a) Planned Capital Projects and Economic Activity Forecast Planned Capital Projects: Scheduled developments - HUD housing School classroom addition Airport improvements Potential developments - Timber harvest Peat harvest Gold mining Economic Activity Forecast: Thé numerous gold mining operations surrounding Takotna offer some potential for increased economic activity in the area. Small-scale timber and/or peat harvest to supply local energy needs is a pos- sibility for development. Neither of these two activities should, however, be expected to be developed until the late 1980's. Rapid economic growth in the area is not anticipated. (b) Population Forecast - Takotna The population forecast is shown in the following TAble 4.12 Table 4.12 Year 1970 1979 1982 1985 1990 2000 Population = 80 88 96 106 129 # Residences - 20 22 24 27 32 # Small commercial - z 2 2; 2 3 # Public users - 3 3 4 4 5 # Large users - 1 Z 1 1 1 ENERGY REQUIREMENTS FORECAST Population growth rate - 2% 4-2 Q) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) 1 Es 2 Sc 3 Addition of new school classroom. apa22:a9 End Use Forecast The end uses of energy are shown in the following Tables 4.12a, 4.12b, TAKOTNA ELECTRIC POWER REQUIREMENTS? and 4.12c. Table 4.12a 1979 Population 80 Number of residential consumers 7 Average kWh/mo/consumer = MWh/year residential consumers (2) x (1) x 12 + 1000 - Number of small commer- cial consumers - Average kWh/mo/consumer = MWh/year small commer- cial consumer (4) x (5) x 12 + 1000 - Number of public consumers 3 Average kWh/mo/consumer 850 MWh/year public consumer (7) x (8) x 12 + 1000 30.6 Large (LP) consumer a (school) Average kWh/mo/LP 7,300 consumer? MWh/year LP's (10) x (11) x 12 + 1000 87.6 System MWh/year (3)+(6)+(9)+(12) 118.2 System load factor 0.6 System demand kW (13)+8760+(14)x1000 22 timated from utility records. hool at 2% growth rate. 1982 88 22 225 59.4 848 20.4 970 34.9 7,747 92.9 207.6 0.45 53 4-3 1985 96 24 - 257 74.0 968 23.2 1,107 53.1 9,975 119.8 270.1 0.45 69 1990 106 27 320 103.7 1,204 _ 28.9 1,379 66.2 11,013 132.1 330.9 0.45 a4 2000 129 32 497 190.8 1,872 67.4 2,142 128.5 13,426 161.1 547.8 0.50 125 apa22:c9 Table 4.12b TAKOTNA HEATING REQUIREMENTS? RESIDENTIAL CONSUMERS 1979 1982 1985 1990 2000 (1) Population 80 88 96 106 129 (2) Number of resi- dential users 20 22 24 27 32 (3) Diesel - Average gal/mo/residence (6)+(2)+12 8 8 8 8 7 (4) Propane - Average lbs/mo/residence (7)+(2)+12 45 45 45 42 38 (5) Wood - Average cords/mo/residence (8)+(2)+12 0.60 0.60 0.60 0.57 0.52 (6) Diesel _ Gals 2,000 2,200 2,400 2,570 25159 Btu x 10° 276 304 331 355 380 (7) Propane __Lbs 10,700 L759 12,840 13,740 14,745 Btu x 10° 209 229 250 268 288 (8) Wood _ Cords 144 158 172 184 198 Btu x 10% 2,448 2,686 2,924 3,128 3,366 (9) Total Btu x 106 (6)+(7)+(8) : 2,933 3,219 3,506 35751. 4,034 (10) Annual per capita consumption Btu x 10 (9)+(1) 36.7 36.6 36.5 35.4 3153 : Assumes a one percent per year decrease in fossil fuel requirements beginning jin 1986 due to implementation of passive solar heating and technical improve- ments in both building desing and heating equipment. 4-4 QQ) (12) (13) (14) (15) (16) (17) (18) (19) apa22-A: R11 Table 4.12c Small Commercial user Diesel Gals/Btu x 106 Public Buildings user Diesel Gals Btu x 10° Large users (school) Diesel equivalent (diesel + wood) Gals Btu x 10° Propane __l1bs Btu x 106 Subtotal Btu x 106 (16)+(17) Total Btu x 106 (9)+(12)+(14)+(18) OTHER CONSUMERS TAKOTNA HEATING REQUIREMENTS? 1979 1982 1985 1990 2 2 2 2 1100. 1100 1100 1046 152 152 152 144 3 3 4 4 1550 1650 2775 2639 214 228 382 364 1 1 1 1 14,770 14,770 20,1822 19,193 2,038 2,038 2,785 2,648 1200 1200 1200 1141 23 23 23 22 2061 2061 2808 2670 5,360 5,660 6,848 6,929 2000 1420 196 3358 463 1033 2418 F ATT, 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 APA32*J16 SECTION 5 RESOURCE AND RECHNOLOGY ASSESSMENT A. ENERGY RESOURCE ASSESSMENT The energy resources which are determined to be available for the village of Takotna 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 Takotna and are therefore not addressed include geothermal, peat, solid waste, oil and gas and tidal power. APA32*%J17 2-S APA22-A S11 Table 5.12 ENERGY RESOURCE LOCATION Diesel fuel Major supplier Bethel Wood fuel 10-mile radius Coal fuel Healy, Alaska Waste Heat! = Recovery Hydroelectric Ganes Creek Potential Wind potential ENERGY RESOURCE ASSESSMENT QUANTITY/AVAILABILITY 10.8x10® cu ft late 1980's Late 1980's 30% of fuel used for electrical generation; upon installation of liquid cooled diesel engines. 1200 kW, 2838 mwh/yr TAKOTNA 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. Villagers indicate insufficient wind in village for wind power. SOURCE OF COST DATA $1.65/gal Village $11.96/10° Btu Meetings $92/cord? Appendix G $6.30/10° Btu $120/ton Appendix H $7.06/10® Btu $450/kW installed Appendix D <$6.58/10® Btu> diesel fuel displaced 89 ,600/kW installed Reference #38 No wind data available. ' Assumes $1.65/gal diesel fuel cost; 0.45 load factor, future diesel generator sets water cooled. 2 Lowered cost due to substantial road network surrounding Takotna. < > saving per million Btu recovered. 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. Hydro site would service Takotna, Ophir and McGrath. SECTION 6 ENERGY PLANS APA32*J18 SECTION 6 ENERGY PLANS A. INTRODUCTION The approach to the energy plans formulated for the village of Takotna 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 Takotna. It is assumed the wood required for fuel would be supplied from timber harvested within a 10-mile radius of Takotna. 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). Hydroelectric generation is investigated for the village. Any additional benefits from these technologies, such as the use of excess hydroelectric energy to provide electric space heat is also included. 6-1 APA32*J19 APA32*J20 SECTION 6 ENERGY PLANS Base Case Plan 1) 2) 3) Plan components - diesel and waste heat recovery Timing of system additions - Diesel - 1982 - 75 kW; 1984 - 75 kW Waste heat equipment - 1984 - 75 kW; 1986 - 75 kW Plan description - This plan assumes installation of a liquid cooled diesel generator in 1982 (replacement for existing air cooled diesels) and the continued use of diesel driven generators (liquid cooled) throughout the study and the implementation of waste heat recovery. Alternative Plan A 1) 2) 3) Plan components - diesel (liquid cooled) and binary cycle generation using wood fuel and waste heat recovery. Timing of additions - Diesel - 1982 - 75 kW; 1984 - 75 kW Binary cycle - 1989 - 150 kW Waste heat equipment - 1984 - 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. Alternative Plan B. z Plan components - diesel and hydroelectric Timing of additions 6-2 SECTION 6 ENERGY PLANS Diesel - 1982 - 75 kW Hydroelectric - 1986, total capacity - 1200 kw, 2838 mWh/yr Portion allotted to Takotna - capacity - 240 kW - 567 mWh/yr 3. Plan description - This plan assumes construction of a hydroelectric project on Ganes Creek, 4 miles southeast of Ophir as replacement for diesel generation in Ophir, Takotna and McGrath (Ref. 38). and to provide supplemental electric space heating during these years where surplus hydroelectric energy is available. Estimated 1980 construction cost of the hydroelectric project is $107,565,000 (Ref. 38). The cost of the project allocated to each community is based upon the estimated percentage of the total annual energy available from the project which will be supplied to each community. These percentages and cost allocation are as follows: Community Percentage of totall Energy Allocated Cost Ophir ~ 5% - $ 5,378,250 Takotna 20% 21,513,000 McGrath 75% 80,673,750 1 Based upon 1979 population data 6-3 APA32*J21 APPENDIX A DESCRIPTION OF SELECTED TECHNOLOGIES APA32*J22 A.1 DIESEL a. General Description 1) 2) APA*32C35 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, 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. Arl 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 in 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 1. 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- jioning 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, 011) 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.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.