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HomeMy WebLinkAboutOuzinkie Reconnaissance Study of Energy Requirements & Alternatives 7-1981Summary Reconnaisance Study of Energy Requirements & Alternatives for . Ouzinkie Prepared For duly 1981 Alaska Power Authority CH2MSEHILL — Summary Reconnaisance Study of Energy Requirements & Alternatives for Ouzinkie July 1981 Alaska Power Authority CH2M SsHILL Prepared For ALASKA POWER AUTHORITY he MM PREFACE This summary contains the results of a study evaluating energy requirements and alternative electricity sources for the com- munity of Ouzinkie near Kodiak Island. The study was per- formed as part of a larger study that included four communities on Kodiak Island and two communities on or near the Alaska Peninsula. This study is described in a report titled Recon- naissance Study of Energy Requirements and Alternatives for Akhiok, King Cove, Larsen Bay, Old Harbor, Ouzinkie, Sand Point, issued in June 1981. It was authorized by the State of Alaska, Department of Commerce and Economic Development, Alaska Power Authority, in a contract with CH2M HILL signed October 9, 1980. iii an MM RECOMMENDATIONS Ouzinkie is located on Spruce Island approximately 20 miles north of Kodiak. It has a year-round population of about 200. The village has grown in recent years and, partly as a result of the availability of a new school and the planned construction of an airstrip, the population is expected to increase. The village electricity sources are two used, 100-kilowatt (kW) diesel engine generators that are now being installed. After installation of the units is com- pleted, the existing 85-kW village generator and a new 50-kW generator at the school will be used only for standby gen- eration. Peak electrical demands for the community, including the school, were 85 kW in 1980; they are expected to grow to 150 kW in the year 2000. The preferred supply source is continued central diesel gener- ation. Because of the relatively small electrical demand of the community, the proposed Katmai Creek hydropower project, which would be located approximately 1 mile east of Ouzinkie, and other hydropower projects, appear to be uneconomic gen- eration sources. Initial investment requirements for the project would be approximately $1.9 million (at January 1981 prices). Recovery of waste heat from the jacket water and exhaust stack from a relocated village generating plant could be an economical energy source if it is used to heat the school. Evaluations show that such a scheme would displace approximately 130 bar- rels of heating oil per year and would have an initial cost of approximately $156,000 (at January 1981 prices). The feasibility of this waste heat recovery project should be investigated. This work would include a more detailed assessment of the problems associated with relocating the village generating plant, development of preliminary layouts for equipment, assessment of the specific heating needs of the school, and preparation of refined cost estimates for the recovery equipment. The study would cost about $30,000. A more detailed investigation of heat energy conservation is needed to determine the feasibility of a weatherproofing and insulation program, primarily for older housing. This investi- gation would include a more detailed characterization of cur- rent insulation levels, the general condition of the existing housing stock, an assessment of heating requirements, and an assessment of both the costs and expected results of alterna- tive conservation programs available to the community. Such an investigation would cost approximately $20,000. CONTENTS Page Preface iii Recommendations 1 Introduction 2 Existing and Projected Energy Requirements 3 Existing Electrical Generation Plant 3 Annual Energy Use 3 Demographic and Economic Forecast 5 Energy Requirements Forecast 5 3 Alternative Sources of Energy 7 Small Hydroelectric Generation 7 Induction Wind Generation 8 Waste Heat Recovery From Central Diesel Engine Generators 8 Heat Energy Conservation 9 Wood Combustion for Electrical Generation 9 Peat Combustion for Electrical Generation 10 Coal Combustion for Electrical Generation 10 Solar Energy (Active Solar Heating and Electrical Generation) 10 Decentralized Wood Burning for Residential Space Heating 11 Single Wire Ground Return Electricity Transmission 11 Preferred Sources of Electricity 11 4 Evaluation of Alternative Electricity Supply Plans 13 Economic Evaluation of Alternative Plans 13 Environmental Evaluation of Alternative Plans 13 Technical Evaluation of Alternative Plans 16 Economic Evaluation of Providing Electric Heating 16 Conclusions 16 Appendix: Detailed Descriptions of Preferred Electricity Sources 19 vii TABLES 1 Forecast of Annual Energy Requirements for Ouzinkie 2 Preliminary Evaluation of Alternative Energy Sources for Ouzinkie 3 Alternative Electricity Supply Plans for Ouzinkie 4 Evaluation of Alternative Electricity Supply Plans for Ouzinkie FIGURES 1 Annual Energy Balance for Ouzinkie ix 12 14 15 MM Chapter 1 MM INTRODUCTION Alternative sources of electricity for the community of Ouzinkie on Kodiak Island were identified and evaluated in the study summarized by this report. The sources recom- mended for further study could help the community reduce its dependence on expensive and often scarce diesel fuel for electrical generation. The purpose of the study was to recommend a series of activ- ities that will result in the identification of feasible alternative sources of electricity. The sources studied include wind generation; peat, wood, and coal combustion for electrical generation; small hydroelectric generation; solar- electric generation; and continued use of centralized or decentralized diesel generation. Waste heat recovery and the conservation of building heat were also evaluated. Establishment of the feasibility of a specific source was beyond the scope of the study. Information about these sources formed the basis for prep- aration of alternative plans to meet Ouzinkie's future demands for electricity. Electrical demands of the school were included in these plans. Each plan was assessed on the basis of its technical, economic, environmental, social, and institutional characteristics. The assessments were performed in accordance with the procedures and assumptions established by the Alaska Power Authority. Further information about this study is contained in a report titled Reconnaissance Study of Energy Requirements and Alterna- tive for Akhiok, King Cove, Larsen Bay, Old Harbor, Ouzinkie, Sand Point, issued by the Alaska Power Authority in June 1981. MM Chapter 2 MM EXISTING AND PROJECTED ENERGY REQUIREMENTS The CH2M HILL project team visited Ouzinkie during October 1980 and, through discussions and meetings with local resi- dents, obtained information on current living conditions, housing, household fuel consumption, employment, subsistence activities, and concerns about local resources. An inspec- tion of the existing generation system was conducted to determine the nature and condition of the plant. Additional information was obtained from published sources and inter- views with local planners. EXISTING ELECTRICAL GENERATION PLANT The village of Ouzinkie owns and operates its own generation plant and distribution system. The city generating system consists of one 85-kilowatt (kW), 1,800-rpm, MED No. 3309, CC-CGE unit, two used, army surplus, 100-kW units (currently being installed), and one standby 60-kW unit at the school. Ten of the 55 houses are not connected with the existing generating system and use individual generators. The city plant operates approximately 15 hours per day, from 7:00 a.m. through 10:00 p.m. Distribution is via a 110-volt system. A new distribution system is being installed. In the past, payment for electricity has been on a flat-rate basis of $60 per month per household. This is now being changed to a metered-rate system that should significantly increase the cost of electricity to each household. The increasing cost of electricity might have a negative effect on the standard of living of local households, but it also will provide incentive for conservation. ANNUAL ENERGY USE Annual fuel consumption records for 1979 show deliveries of 360 barrels of diesel fuel and 1,070 barrels of home heating fuel. End uses of heating fuel include space heating, cooling, and water heating. Propane is used occasionally. Approxi- mately 10 new houses under construction by the U.S. Department of Housing and Urban Development are being equipped with wood stoves for heating. Estimated total village generation is 158,000 kilowatt-hours. Peak demand is estimated to be 85 kw. End uses of electricity include lighting and the operation of appliances such as refrigerators, freezers, televisions, washers, and dryers. Figure 1 summarizes energy information for Ouzinkie. IMPORTS END USE MOTOR VEHICLE AND : GAS 20,000 GAL OTHER USE a Bee (ESTIMATED) NON-RECOVERABLE GENERATION WASTE HEAT 1,411 x 10° Btu RECOVERABLE GENERATION WASTE HEAT 900 x 10° Btu CITY GENERATION 158,000 Kwh DIESEL FUEL 360 bbl HOME HEATING 1,070 bbl CITY HEATING 8,474 x 10° Btu FUEL FIGURE 1 ANNUAL ENERGY BALANCE FOR OUZINKIE DEMOGRAPHIC AND ECONOMIC FORECAST Population is conservatively estimated to increase at an average annual rate of 1.8 percent over the next two decades. This will result in an increase of 72 people, or approxi- mately 20 households. The housing stock is expected to increase at a higher rate than population during the next 20 years (an average annual increase of 3.5 percent). Increases in the housing stock are based on known, planned housing development and pro- jected increases in population. Fifteen HUD-supported houses are planned for construction during 1981. This relationship between population and housing projections will allow for future decreases in average household size (per- haps from 4.0 to 3.2 people per household) and an increase in housing market flexibility (i.e., a vacancy rate slightly greater than zero). The preceding projections of population and housing require- ments depend on future economic activity and land availabil- ity. However, because of the closeness of Ouzinkie to Kodiak (which will be even more closely linked once an airstrip is constructed) and the strong family ties among village mem- bers, it is expected that some increase in population will occur regardless of future changes in economic opportunities. For example, some people with seasonal employment in another location might choose to make their permanent residence in Ouzinkie. It is not expected that employment opportunities in Ouzinkie will increase dramatically during the next two decades, al- though some slight expansion in employment might occur because of growth in fishing, local business, and government. Ouzinkie is thus expected to remain a relatively stable community during the next 20 years. ENERGY REQUIREMENTS FORECAST Annual energy requirements for Ouzinkie were projected to the year 2000 (Table 1). Fuel use is projected to increase 20 percent between 1980 and 1981 and 2 percent annually from 1981 through 2000. This growth rate is directly related to increases in housing stock; there was no basis for assuming any increase in average per-capita consumption. Over a 20- year period these annual growth rates will result ina 75 percent increase in both fuel and electricity requirements. The village peak demand for electricity was projected to remain at its current load factor of 21 percent. Table 1 FORECAST OF ANNUAL ENERGY REQUIREMENTS FOR OUZINKIE Fuel (bbl/yr)* 1980 1990 2000 Diesel (generation) 360 516 629 Home Heating Fuel (heating) 1,070 1,535 1,871 Total 1,430 2,051 2,500 Generation (kWh/yr) Village 158,000 226,600 276,200 Peak Electric Power Requirements (kW) Village 85 121 150 *One barrel equals 55 gallons. MM Chapter 3 MM ALTERNATIVE SOURCES OF ENERGY Alternative sources of electricity available to the commun- ity are identified and described in this chapter. The accuracy of these descriptions is consistent with the amount of data available from site investigations and research on the alternatives. Continued use of centralized or decen- tralized diesel electric generation is included as an alter- native. Near-term alternative heat energy sources are also identified and characterized. Specific alternative energy supply projects that were con- sidered include: Continued central diesel electric generation Katmai Creek hydropower Waste heat recovery at relocated central village generation plant Unnamed creek hydropower Peat combustion for generation Wood combustion for generation Coal combustion for generation Decentralized solar-electric generation Induction wind generation Decentralized active solar heating Heat conservation Decentralized wood burning for space heating Single wire ground return electricity transmission ooo o000000000 General descriptions of these energy sources are provided below. SMALL HYDROELECTRIC GENERATION Hydroelectric energy is generated when flowing water spins a turbine, which drives a generator, producing electric energy. Hydroelectric generation is considered a renewable resource because the input energy source (falling water) is not de- pleted over time. Operating small-scale hydroelectric plants can also be relatively inexpensive. Use of the water is often free and hydroelectric plants cost little to operate and maintain. Also, the cost of the electricity produced by a hydroelectric plant remains relatively constant over time. Costs rise only when inflation increases operation and main- tenance costs, which constitute only a small portion of total plant costs. The major project cost is for initial construc- tion, which can be financed and paid for in equal periodic payments that will not increase with inflation. Small hydroelectric projects can be practical in many Alaska locations. The technology has been tested and proven in Alaska and throughout the world, and the skills needed to design and build plants are readily available. Rapid and efficient construction is possible, which minimizes costs. The environmental impacts of small hydroelectric plants are usually slight and can often be easily mitigated. Most of the small hydroelectric projects considered for this study would require a small diversion dam to create a small reser- voir, a penstock to transmit the water from the reservoir to the powerhouse, and a small powerhouse. INDUCTION WIND GENERATION Several kinds of wind-powered electric generators are com- mercially available, but they all share the same operating principle: the wind rotates the blades of a collector, which drives a generator to produce electricity. To attain the high speeds necessary for electrical generation, these wind machines must have airfoil blades similar to those of an airplane propeller. The axis of rotation for the collec- tor can be either horizontal (like a farm windmill) or ver- tical (like an eggbeater). The electricity produced can either be alternating current (induction generation, which was considered in this study, or synchronous generation) or direct current (which can be stored in small quantities in electric storage batteries). Because the wind is intermittent, a wind generator must be backed up by another generation source. In Alaska, this usually will be a conventional diesel engine generator. Wind generators also have a high initial cost and, because they are a relatively new source of electricity and are exposed to the elements, require more frequent maintenance than con- ventional generators. However, their environmental impact is minimal, except for some noise during operation. WASTE HEAT RECOVERY FROM CENTRAL DIESEL ENGINE GENERATORS The waste heat created by diesel engine generators can be captured and used for space heating. Ordinarily, two-thirds of the energy contained in the diesel fuel supplied to such a generator becomes waste heat that enters the environment via either the engine radiator or exhaust system. Almost all the radiated heat and about half the exhaust heat can be recovered. This means that up to half the energy content of diesel fuel can be recovered and converted into space heat for a building, if the building is within "economic proxim- ity" to the generator (that is, if the cost of capturing, transporting, and using the heat is less than the cost of space heating by other means). The medium ordinarily used to recover and transport the waste heat is water. A water-to-water heat exchanger captures heat from the engine jacket water, and an air-to-water heat exchanger captures exhaust stack heat. The heat is trans- ferred to water that flows through a pipeline to a radiant space heating system. Another pipeline carries the used water back to the heat exchanger. One building or a build- ing complex can be heated in this manner. These systems can require a sizable initial investment, but they are usually very reliable and make use of a source of energy that would otherwise be wasted, so their fuel costs nothing. HEAT ENERGY CONSERVATION Conservation of heat used in buildings is possible through an increase in the buildings' thermal efficiency by addition of wall, window, ceiling, and floor insulation. Three types of buildings were considered in this study: school buildings, housing built before 1964, and housng built after 1964. No conservation options were assessed for school buildings because, in general, schools are of recent construction and are equipped with adequate heat conservation devices. In newer housing, existing building components such as roofs, walls, windows, and floors provide adequate thermal effici- ency, although investigations of individual residences would probably result in specific recommendations for particular dwellings. In older housing stock, existing structural com- ponents do not provide adequate thermal efficiency. The major opportunity for heat conservation therefore lies in developing insulation programs for older housing stock. In newer housing that is presently heated with central forced air furnaces using gun-type oil burners, replacement with flame retention burners could reduce heating fuel consump- tion considerably. Overall, average conversion efficiency of the furnaces could be improved from about 73 percent to 85 percent with the use of these fuel-efficient burners. WOOD COMBUSTION FOR ELECTRICAL GENERATION Wood can be harvested, processed, and burned for steam tur- bine generation or piston engine generation. The renewabil- ity of wood as a fuel depends on timber growth rates, forest density, and the size of the forest area dedicated as a fuel source. Often, a very large area is required to fuel a municipal power plant, and a considerable amount of machinery and labor is needed to harvest and process the wood. The environmental costs can also be high. Harvesting can affect the land, water, and wildlife of the forest, and large-scale wood combustion can cause air pollution. PEAT COMBUSTION FOR ELECTRICAL GENERATION Dried peat can be used as boiler fuel for steam turbine generation or piston engine generation, much the same way wood can be. The peat must be cut, gathered, dried, and compressed into briquettes before it can be burned. Peat may be considered a renewable energy resource, but the degree of renewability depends on the rate of use, regrowth rate, and size of the peat field dedicated as a fuel source. As with the use of wood, a considerable amount of machinery and labor is needed to harvest and process peat. The envi- ronmental costs can also be high. Harvesting can affect the land, water, and wildlife of the peat field, and peat com- bustion can cause air pollution. COAL COMBUSTION FOR ELECTRICAL GENERATION Coal can be burned in a boiler to produce steam, which can be used to drive a steam piston engine generator or a steam turbine generator. Coal is considered a nonrenewable resource that is relatively abundant but must usually be obtained from a distant supply source, much the same way diesel fuel must be obtained. Coal combustion technology is proven and reli- able, but the burning of coal can have a significant effect on air quality. This can be mitigated through the use of pollution control equipment. SOLAR ENERGY (ACTIVE SOLAR HEATING AND ELECTRICAL GENERATION) Much of the earth's energy is derived directly from the sun through solar radiation. This radiation can be collected and used for space heating or to produce electricity. Both systems were considered in this study. A solar space heating system typically consists of a solar collection device and a fluid to transfer heat from the col- lector to a space heating system in a building. The system can also include a means for storing the heat when the demand for space heating is low. A system to produce electric energy typically consists of an array of photovoltaic cells and a set of batteries that store the electric energy produced by the cells. The photovoltaic cells produce direct current. If alternating current is needed, as is usually the case for a house, an inverter is required. Additional electrical control systems are used to regulate the system's operation. Solar heating and photovoltaic systems can be designed for use in Alaska, but they are ordinarily quite expensive. They require a very large initial investment and often more main- tenance than alternative energy supply resources. The systems 10 also require some form of backup system that will supply a user's needs during those times when demand is greater than the solar system can supply. DECENTRALIZED WOOD BURNING FOR RESIDENTIAL SPACE HEATING Wood can be harvested, processed, and burned in household stoves for space heating. This is a very simple, reliable technology, but the attractiveness of wood as an energy source depends on timber growth rates, forest density, and the size of the forest area dedicated as a fuel source (driftwood can also be used). A very large area might be required to heat a community, and a considerable amount of labor and machinery is needed to harvest and process the wood. The environmental costs can also be high. Harvesting can affect the land, water, and wildlife of the forest, and can be quite noisy. SINGLE WIRE GROUND RETURN ELECTRICITY TRANSMISSION Single wire ground return (SWGR) electricity transmission operates in single phase and consists of a single overhead line. The earth acts as the second or return wire. A-frame pole construction eliminates hole augering and the associ- ated problems of pole jacketing in permafrost. In addition, local timber can be used for the poles. Single wire ground return transmission technology is relatively new, but it has been used successfully between the villages of Bethel and Napakiak, Alaska. PREFERRED SOURCES OF ELECTRICITY The alternative sources of energy identified at the beginning of this chapter were each evaluated on the basis of economic, environmental, and reliability and safety considerations, and conformance with community energy-source preferences. Out of this evaluation, summarized in Table 2, three pre- ferred or best alternatives were selected for further analysis. These are described in detail in the appendix and considered further as part of the alternative electricity supply plans described in Chapter 4. 11 Table 2 PRELIMINARY EVALUATION OF ALTERNATIVE ENERGY SOURCES FOR OUZINKIE Preferred Energy Sources (selected for further analysis) Continued centralized diesel-electric generation Katmai Creek hydropower Waste heat recovery at relocated village central generating plant Other Energy Sources (not considered further) Unnamed creek hydropower Peat combustion for generation Wood combustion for generation Coal combustion for generation Decentralized solar-electric generation Induction wind generation Decentralized active solar heating Heat energy conservation Decentralized wood burning for space heating Important Characteristics No initial investment required No significant adverse environmental impacts High reliability Proven technology See note below Small initial investment required Low operating cost and no fuel cost No significant adverse environmental impacts High reliability Proven technology Important Characteristics See note below High initial investment requirement High operating cost High fuel cost Significant adverse environmental impacts Prohibitively high initial invest- ment requirement Unproven technolgy High initial investment requirement Not an electricity generation source and thus not considered further Note: Katmai Creek is the lower cost hydropower project, according to Corps of Engineers data (October 1980). 12 WM Chapter 4 MM EVALUATION OF ALTERNATIVE ELECTRICITY SUPPLY PLANS This chapter identifies and evaluates alternative electricity supply plans. The plans use the preferred energy sources described in Chapter 3 to meet both peak electrical require- ments and annual energy requirements. Continued use of existing diesel engine generation is considered an alterna- tive supply plan and is identified as Plan A, Base Case. Supply plans to meet future space-heating requirements were not developed. Alternative supply plan descriptions are contained in Table 3, and plan evaluations are summarized in Table 4. ECONOMIC EVALUATION OF ALTERNATIVE PLANS Alternative electricity supply plans were evaluated on the basis of total plan costs for installation, operation, and fuel for both the next 20 and 50 years. Total plan costs are shown in Table 4 in the columns headed "Present Value of Plan Costs." In accordance with Alaska Power Authority guidelines, the present value of plan costs is the sum of all costs (initial investment, operation and maintenance, and fuel) associated with a plan during the 20- or 50-year planning period. To obtain the present value of these costs, plan costs in their year of expected occurrence were dis- counted back to January 1981 at 3 percent per year. The rate of general inflation was assumed to be zero percent per year, but diesel fuel prices were assumed to rise at an average annual rate of 3.5 percent. This method of evaluation is fair to both the continued use of diesel generation and the alternative development of new generation sources that involve high initial costs and low operating costs, such as hydropower projects. The 3.5 per- cent annual rise in diesel fuel prices is significantly lower than the actual rise in these prices is expected to be, but the 3-percent amortization rate for high-initial-cost sources such as hydropower projects is also significantly lower than these rates are expected to be, so both types of sources receive equal treatment. ENVIRONMENTAL EVALUATION OF ALTERNATIVE PLANS Evaluations of the environmental impact(s) of alternative electricity supply plans are based on assessments of the following impacts: ° Air quality ° Water quality 13 vT Plan A (Base Case) Table 3 ALTERNATIVE ELECTRICITY SUPPLY PLANS FOR OUZINKIE Plan Description Continue use of central diesel generation. Service recently constructed school with village electric system, place school generation system on ee entie installing two 100-kW engine generator units; place existing 85-kW unit on standby. Replace one 100-kW unit with a 150-kW unit in 1991 ($400/kw). Develop and operate Katmai Creek hydropower plant. Service recently constructed school with village electric system; place school generation system on standby. Plan and license hydropower project in 1981 and 1982; costs are approximately $50,000 in 1981 and $100,000 in 1982. Install and construct hydropower plant in 1983 and 1984. Plant available in January 1985. Backup generation from existing central diesel plant. Minimum diesel backup plant operating, maintenance, and fuel cost is $10,000 per year. Install and operate waste heat recovery system at relocated village generation plant to provide school heating. Continue use of central diesel generation. Planning and installation in 1981. Available in January 1982. Diesel plant replacement schedule same as Plan A. Note: All costs are based on January 1981 price levels. ST EVALUATION OF ALTERNATIVE Table 4 ELECTRICITY SUPPLY PLANS FOR OUZINKIE 20-Year Planning Period Present Value of Plan 50-Year Planning Period Present Value of Plan Plan Plan Description Costs _($)* Costs ($)* Energy Performance Environmental Impacts Reliability/Safety aA Continued central 0.83 million 1.83 million Sufficient to meet com- No major impacts Highly reliable, minor (Base diesel-electric munity (village and safety concerns Case) generation school) electric re- quirements B Katmai Creek 1.53 million 2.41 million Sufficient to meet com- Potentially adverse Highly reliable, backup hydropower munity (village and environmental impacts. with central diesel gener- project school) electric No identified adverse ation. Some safety con- requirements impacts on salmon cerns regarding seismically species. Reservoir may induced dam structural affect feeding areas of failure. deer. ¢c Waste heat 1.02 million (plan 2.13 million (plan Sufficient to meet com- No major impact Highly reliable, minor recovery from cost) cost) munity electric re- safety concerns relocated +20 million (heat- 0.42 million (heating quirements and displace village central ing credit) credit) approximately 130 barrels diesel-electric 0.82 million (net 1.71 million (net of heating oil per year generation plan cost) plan cost) @3anuary 1941 costs. Fish and wildlife Land use Terrestrial Community infrastructure and employment Other planned capital projects 00000 Detailed estimates of the magnitude of an impact were not possible. However, major concerns are identified and in- cluded in the evaluations. Alternative energy systems were designed to be environmentally acceptable. In those instances where additional equipment was required to make a source acceptable, the costs of such equipment were included in cost estimates. Detailed descriptions of possible environmental impacts are contained in the appendix. TECHNICAL EVALUATION OF ALTERNATIVE PLANS Alternative electricity supply plans were formulated to result in generation systems of similar reliability and safety that would be capable of meeting the complete elec-— tricity needs of the community. Detailed descriptions of each alternative's reliability and safety are contained in the appendix. ECONOMIC EVALUATION OF PROVIDING ELECTRIC HEATING The Katmai Creek and unnamed creek hydropower projects were assessed to determine whether they could provide economical electricity for lighting, appliances, and other conventional uses, and for new electric heating systems. The assessment indicated that neither hydropower project would be an econom- ical generation source even if excess electric energy avail- able from the project (above that required to displace diesel engine electric generation) were used for electric heating. Year 1990 estimated hydropower costs for Katmai Creek are approximately $86,000, but the estimated total cost of the energy that would be displaced is only $61,000. Year 1990 estimated hydropower costs for unnamed creek are approxi- mately $306,000, but the estimated total cost of the energy that would be displaced is only $215,000. CONCLUSIONS From the information in Table 4, continued central diesel engine generation for both community and school use appears to be the least costly source of electricity. Continued diesel generation, when evaluated over both 20- and 50-year periods, will cost significantly less than development and operation of alternative generation sources. The present value of the 20-year cost for continued central diesel elec- tric generationis $0.83 million. The present value of the next least expensive alternative is $1.53 million. In addi- tion, continued central diesel-electric generation isa 16 reliable generation source (when adequate fuel supplies are available) and involves relatively few environmental or safety concerns. Table 4 shows waste heat recovery at a relocated village diesel generation plant could be an appropriate energy resource. The present value of the 50-year costs of waste heat recovery is $1.71 million, which compares favorably with the $1.83 million for continued diesel-electric generation without waste heat recovery. 17 MM Appendix MM DETAILED DESCRIPTIONS OF PREFERRED ELECTRICITY SOURCES 19 Resource/Village: Continued central diesel generation/Ouzinkie Energy Form: Electric energy General Description: Continued diesel electric generation with recently installed engine generator units Resource Location: Ouzinkie Renewable or Nonrenewable: Nonrenewable Resource Characteristics: Diesel generation plant consists of two new 100-kW engine generator units (currently being installed), one existing 85-kW engine generator unit (to be standby), and one 55-kW engine generator unit (school standby). Maximum village plant output is 200 kW before additional generator units required. Energy Production: Estimated conversion efficiency is 10.5 kWh per gallon fuel oil. Input Energy (fuel) Characteristics: NA Resource Reliability: Engine generator unit(s) highly reliable; questionable avail- ability of diesel fuel supply Resource Cost (January 1981 price levels): Replacement cost ($/kW) 400 Operating and maintenance cost (¢/kWh) 2.6 Current fuel cost ($/gal.) 1.40 Maintenance Requirements: Periodic maintenance required. Minor overhaul required every 8,000 operating hours. Major overhaul required every 24,000 operating hours. Operating activity requirement is 1 hour per day for one operator/maintenance person. Resource Development Schedule: NA Environmental Impacts: No major impacts Institutional, Social, and Land-Use Considerations: No major considerations Health and Safety Impacts: No major considerations 21 Resource/Village: Hydropower plant on Katmai Creek/Ouzinkie Energy Form: Electric energy General Description: A low concrete diversion dam diverts water into a penstock that runs parallel to Katmai Creek. Powerhouse located near the mouth of the creek. Site does not have room for an earthfill dam and separate spillway. Resource Location: About 1 mile above the mouth of Katmai Creek, 0.5 mile east of Ouzinkie Renewable or Nonrenewable: Renewable Resource Characteristics: Dam Type Height (ft) Operation Spillway Type Capacity (cfs) Penstock Length (ft) Diameter (in) Powerhouse Type of machine Number of units Installed capacity (kW) Transmission Facilities Type Length (miles) Energy Production: Installed capacity (kW) Average annual energy (kWh) Plant factor (%) Dependable capacity (kw) Annual energy, low-flow year (kWh) Annual energy, high-flow year (kWh) Input Ene (Fuel) Characteristics: Drainage area (sq. mi.) Average annual flow. (cfs) Low flow (cfs) High flow (cfs) Total head (ft) Net head (ft) Maximum penstock flow (cfs) Concrete diversion 10 Run-of-river Concrete overflow 1,300 (500-year peak flow) 2,100 30 Reaction 1 78 single wire, ground return 0.5 78 339,000 50 12 271,000 407,000 2.34 18.7 1.6 1,020 50 44 29 Resource Reliability: The project is located on a stream with a small drainage area, and it is sized to use most of the available flow. For this reason the output of the plant is subject to natural fluctuations in runoff. The project has no storage to carry over generation capability during dry periods. Resource Cost (January 1981 pr Construction and engineering (S$) Unit cost ($/kW) Annual operating and maintenance ($) ice levels): 1,677,000 21,500 15,275 Maintenance Requirements: Periodic maintenance will be required to overhaul or replace worn-out or defective parts. The frequency should be minimal because the technology for hydropower projects has been developed and proved. Hydropower projects of this size can be operated with very minimal manpower and/or can be operated by remote telecommunications. Useful operating lifetime is 30 to 50 years. Resource Development Schedule: Installation and construction in 1983 and 1984, available in January 1985 Environmental Impacts: No identified adverse impacts on salmon species. Reservoir may affect feeding areas of deer. Institutional, Social, and Land-Use Considerations: Possible land-use conflicts resulting from siting plant and transmission system. Health and Safety Impacts: No significant impacts 23 Resource/Village: Waste heat recovery at city generating plant/Ouzinkie Energy Form: Hot water General Description: Reclaim exhaust and jacket water heat from one 100-kW engine generator (currently being installed at different location). Generator to be relo- cated to a new building next to the Ouzinkie school. Requires new floor slab and building, new 1/4-mile transmission line, and new pipe system to transmit hot water (200°F) to school interior spaces. Resource Location: Ouzinkie school site Renewable or Nonrenewable: Not applicable Resource Characteristics: Resource components are (1) 200 feet of 3-inch-diameter outside pipe (insulated), (2) 400 feet of 2-inch-diameter interior piping, (3) four hot water unit heaters (100,000 Btuh rating), (4) one heat recovery silencer, (5) one heat exchanger (shell and tube type), (6) one building hot water circulation pump, (7) one expansion tank (20-gallon), and (8) one Butler-type building with concrete floor slab. Energy Production: Approximately 295,000 Btu per hour hot water production at 50-kW average electric output. Average heat available at school is 265,000 Btu per hour. Annual energy (fuel) savings is estimated at 1,050 million Btu (7,300 gallons No. 2 fuel oil). Input Energy (fuel) Characteristics: System operates utilizing engine stack exhaust and jacket water heat from new and relocated village generation plant. Resource Reliability: Highly reliable Resource Cost (January 1981 price levels): Construction and engineering (S$) 156,000 Annual operating and maintenance ($) 5,500 Maintenance Requirements: No additional generation plant operators required. Inspect piping, valves, unit heaters monthly. Visually check heat recovery system whenever engine is checked. Four weeks' maintenance (one person) required per year. Average equipment replacement cost is $900 per year. Resource Development Schedule: Installation and construction in 1981, available beginning January 1982 Environmental Impacts: No major impacts Institutional, Social, and Land-Use Considerations: No major considerations Health and Safety Impacts: No major impacts 25 Alaska Power Authority 334 W. 5th Ave. Anchorage, Alaska 99501