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Home My WebLink AboutReconnaissance Study Of Energy Requirements & Alternatives For The Villages 1982MAIN VOLUME { RECONNAISSANCE STUDY OF ENERGY REQUIREMENTS AND ALTERNATIVES FOR THE VILLAGES OF ANIAK, ATKA, CHEFORNAK, CHIGNIK LAKE, COLD BAY, FALSE PASS, HOOPER BAY, IVANOF BAY, KOTLIK, LOWER AND UPPER KALSKAG, MEKORYUK, NEWTOK, NIGHTMUTE, NIKOLSKI, ST. GEORGE, ST. MARYS, ST. PAUL, TOKSOOK BAY AND TUNUNAK LIBRARY COPY PROPERTY OF: Alaska Power Authority ocd RAP as NORTHERN TECHNICAL SERVICES é and VAN GULIK and ASSOCIATES . » Anchorage, Alaska March 1982 NORTHERN TECHNICAL SERVICES ANCHORAGE, ALASKA NORTHERN TECHNICAL SERVICES 750 WEST 2ND AVENUE, SUITE 100 * ANCHORAGE, ALASKA 99501 (907) 276-4302 March 4, 1982 Mr. Eric Yould Executive Director Alaska Power Authority 334 W. 5th Avenue Anchorage, AK 99501 Dear Mr. Yould: Please find herein our Draft Report, Reconnaissance Study of Energy Requirements and Alternatives for the Villages of Aniak, Atka, Cherfornak, Chignik Lake, Cold Bay, False Pass, Hooper Bay, Ivanof Bay, Kotlik, Lower and Upper Kalskag, Mekoryuk, Newtok, Nightmute, Nikolski, St. George, St. Marys, St. Paul, Toksook Bay and Tununak. This draft report has been prepared within the guidelines provided under 3 AAC 94.055, RECONNAISSANCE STUDIES and under the direction of Ms. Patti DeJong of your offices. Your critical comments and those of your staff, relative to this draft, will be most welcomed. The staff and authors of the report wish to thank you and your staff for the sense of cooperation which prevailed during its preparation. Should you have any questions, please call on us at your convenience. Very truly yours, NORTHERN TECHNICAL SERVICES MIA ot hele Robert W. Huck Senior Associate RWH:slw RECONNAISSANCE STUDY OF ENERGY REQUIREMENTS AND ALTERNATIVES FOR THE VILLAGES OF ANIAK, ATKA, CHEFORNAK, CHIGNIK LAKE, COLD BAY, FALSE PASS, HOOPER BAY, IVANOF BAY, KOTLIK, LOWER AND UPPER KALSKAG, MEKORYUK, NEWTOK, NIGHTMUTE, NIKOLSKI, ST. GEORGE, ST. MARYS, ST. PAUL, TOKSOOK BAY AND TUNUNAK A DRAFT REPORT by NORTHERN TECHNICAL SERVICES and VAN GULIK and ASSOCIATES Anchorage, Alaska March 1982 TABLE OF CONTENTS 1.0 INTRODUCTION 2.0 BACKGROUND 3.0 METHODOLOGY 3.1 Village Contacts 3.2 Data Collection 3.3 Energy Balance Calculations Projections Alternative Sources of Energy Sei4 SRD 3.6 Formulation of Electrical Energy Plans 3.7 Plan Evaluation 3.218 Recommendations 4.0 CRITERIA EMPLOYED TO DETERMINE THE PRESENT DEMAND, ENERGY USE AND COSTING FOR THE INSTALLATION OF CENTRAL GENERATION SYSTEMS IN THE VILLAGES 4.1 Methods 4.2 Total Energy Used and Total Peak Power Estimates 4.3 Costing 5.0 SUMMARY OF FINDINGS APPENDIX A Technology Profiles Al. Energy Conservation A2. Diesel Power Technology A3. Waste Heat Recovery from Diesel Generators A4. Hydroelectric Power A5. Wind Energy Conversion Systems A6. Geothermal Energy A7. Steam Power Generation from Coal/Wood/Solid Waste/Peat A8. Gasification of Wood, Peat or Coal A9. Synchronous, Induction or DC Generation Systems A10. Electrical Generation Management All. Electric Power Transmission - Single Wire Ground Return (SWGR) 1.0 INTRODUCTION Northern Technical Services (NORTEC) with Van Gulik and Associates, Inc. entered into a contract with the Alaska Power Authority during November, 1981 to perform energy reconnaissance studies at 20 rural Alaskan communities. These are: Aniak, Atka, Chefornak, Chignik Lake, Cold Bay, False Pass, Ivanof Bay, Hooper Bay, Kotlik, Lower and Upper Kalskag, Mekoryuk, Newtok, Nightmute, Nikolski, St. George, St. Marys, St. Paul, Toksook Bay and Tununak. The villages are located in western and southwestern Alaska and in the Aleutian Islands (see figure 1.1). All of the villages are primarily dependent on imported fuel for the generation of electricity as well as for space heating. Fuel is delivered to the villages by barge and the deliveries are made on an annual or semi-annual basis. The primary objective of the reconnaissance studies was to identify existing and future power production needs of the communities and to investigate potential alternative sources of energy and new technologies to meet these needs in the least costly manner. Realistically, the question to be addressed is not purely one of energy economics but is a social question as well. That is, costly services are being supplied to rural native Alaskans who have little discretionary income and, at pesent, very limited opportunity for local income generating employment. To address all of the implications of this situation is beyond the scope of an energy reconnaissance investigation. Where possible this study has been designed to identify potential opportunities for local employment which would result from energy projects or increased employment which 1-1 Cal T°T eanbtg OMNODOSUN KEY KOTLIK SAINT MARYS KALSKAG ANIAK LOWER KALSKAG NEWTOK NIGHTMUTE CHEFORNAK MEKORYUK TOKSOOK BAY TUNUNAK HOOPER BAY CHIGNIK LAGOON CHIGNIK LAKE IVANOF BAY FALSE PASS COLD BAY NIKOLSKI ATKA ST. PAUL ST. GEORGE F212 Sane ages 2 x tance 7 Sing 7 st | i ee KaLsKag Bo 44 rununan— 7 eS newrox G ; - 10 tox: wD vs f y j g NEKO . Spey? Gy ly os —— ttn if 5 At i c . as. Px vaso ZR rowisnm OR ot FN emai vane 14 “ & *4 ay oS 5 . pat y) Sa 60 a) 60 120 180 240 300 miLES Se ae a te LOCATION MAP result of lowered energy costs. Energy alternatives for the communities have been assessed on the basis of the following criteria: economic comparison with present power costs technical feasibility social benefits to be derived energy resource availability, quality and magnitude environmental impacts community preferences This report follows the Power Authority's recommended outline format, allowing information for these communities to be compared with that of communities under investigation by other contractors. The required components of an energy reconnaissance as defined by the Power Authority have been incorporated into this study as the primary tasks. Each of the community energy reconnaissance investigations included the following basic tasks: ° An on-site reconnaissance visit - These visits allowed the study team to investigate many aspects of the community's present energy supply and demand, to assess potential alternatives, to learn of the community's plans, preferences and ideas for use of energy resources. Each community visit included preliminary contact with key village representatives, a town meeting and additional personal contacts with many of the village residents in addition to the facility and resource reconnaissance investigations. A complete energy balance compilation and analysis - The energy balance data not only provides necessary information for system planning and ies economic analysis but also provides an overview of existing energy requirements and sources. o A forecast of electrical energy peak load requirements through the year 2001 - The forecasts are basic tools for matching energy resources and future community needs and for preliminary economic analysis. o Technology profiles - Profiles of those technologies with the potential to replace or enhance diesel generation or to otherwise decrease the proportion of individual income spent on energy were prepared. Detailed profiles are included as an appendix to this report. o Energy system options - Preferred energy options estimated costs and recommendations for energy alternatives are made. Investigations prerequisite to further consideration of the energy options are also suggested herein. Site-specific energy alternatives were considered for the twenty communities. The conclusions, as presented, are based upon: o The on-site reconnaissance including information provided by local residents of the villages, visual inspection, and subjective reactions. o Limited data on stream flows, mean wind velocities, solar incidence and fuel resources at the site or in the approximate area under consideration. o State-of-the-art information obtained from experience, vendor data and reports in the technical and professional literature. o Preliminary economic analyses using engineering parameters, estimated cost information and resource data. As in any analysis of alternative energy scenarios, it has been necessary to consider technologies of varying reliability and availablity. Few of the newer technologies have been field tested in rural Alaska. Consequently, it is not possible to accurately assess investment risk. However, some systems may warrant further investigation, if the potential benefit appears to be significant. Since the Power Authority has requested alternatives which can be implemented in the near future in order to meet the serious and immediate energy needs of rural Alaskans, only those technologies which are available have been recommended for further investigation. Other technologies may have great potential for these rural communities, but the status of their development is such that they can only be considered reliable long-term solutions. In most instances traditional economic analyses will not favor a new energy conversion system, but the long-term reliability of a local or renewable energy resource has a real or social value that is difficult to quantify. In most of these cases, new technologies must be demonstrated under Alaskan conditions before economic analyses can be considered sufficiently rigorous. The demonstrated value of an alternative energy system operating in Alaska is important not only to those benefiting directly from the energy conversion but also to those investors (public and private) who will be encouraged to implement similar alternatives. Some energy alternatives have been eliminated from further investigation as part of this reconnaissance for one or more of the following reasons. © Resource availability, magnitude, or quality unsuitable in the vicinity of the village 5 Conversion technology considered very high risk (not proven) Extraction or conversion technology very expensive for scale of operation anticipated based on best estimates of population and/or industry growth BACKGROUND General As the life style of the villages in western Alaska and the Aleutians has moved away from total subsistence, a dependence on imported fossil fuels has arisen. These fossil fuels are needed for electrical generation, space heating, cooking and transporation. The emphasis of the Energy Reconnaissnace Program is electricity - its generation, supply, demand and costs. Further, cost and reliability are of critical importance to the villages. Fuel prices have risen rapidly, resulting in dynamic and escalating costs for electricty. Costs are also influenced by the relative lack of trained power plant operators in the communities who have been trained in the installation, operation and maintenance of power generation systems. The remote nature of the villages in concert with the rudimentary transportation systems in Alaska also poses a serious problem in supplying spare parts and highly skilled mechanics to perform major repair work. In view of the above, it is essential that the efficiency and cost-effective operation of existing generators be maximized at the village level. The villages in this study generally have a restricted cash economy that is inadequate to support year round employment for all but a few of their residents. The majority of the villages are planning for the development of a broader base for their local economy. A basic requirement for such an expansion is a reliable and reasonably priced supply of electricity. Space heating is the major end use for fuel oil in the villages. Energy use is high because the houses tend to be poorly constructed with high infiltration rates. Inadequate insulation in many homes causes excessive heat loss through walls, floors and ceilings. In many places where wood and other alternative sources of heating fuel are available, villagers are converting their appliances to make use of the lower priced fuels. Resources Electrical generation is fueled by diesel in all the villages in the study. Generators in the village are producing from 4 to 11 KWH per gallon of diesel fuel. The lower production rate is usually found in those villages where small generators are installed at individual dwellings. These small individual generators have high operation maintenance and capital costs (on a per KWH basis). Inefficient energy production rates (5-6 KWH/gal) are encountered in central generation systems where the engines are excessively oversized. Further, the resulting low loads on the central generators results in high operation and maintenance costs. Village systems with high conversion rates (10-11 KWH/gal) have generators matched to the load and use night switching. These units are well maintained and their performance is continually monitored to insure maximum efficiency. Most generators have been installed to produce electrical power only. Initially, no consideration was given to recovering heat from the engines to provide space heat to some of the buildings in the village. Recently, as a result of high fuel costs, waste-heat capture has been demonstrated at a number of sites and is generally perceived as the most readily available means for reducing use of oil. An efficient and economical waste-heat capture system requires a central generation plant that is located near a large heat consumer, usually a school or public building. Hydro-power is a viable alternative source of electricity where the flow of water at a site can be assured throughout the year and where the stream course is steep. Small streams in the Yukon-Kuskokwim region have low gradients and freeze in the winter which precludes development potential. The Aleutian Islands and southern Alaska Peninsula experience milder climates have mountainous topography and high potential for economical small scale hydropower developments. In most cases, villagers are aware of the economic benefits to be gained from the development of local hydro-electric potential. Generation of electrical power from the wind has yet to be proven economically or technically viable. The extreme range of wind velocities especially in mountainous regions precludes the use of any wind powered generators available on the market today. Most wind systems require an operating utility to provide magnetizing current and frequency regulation to control the output. There is not sufficient data at this time to demonstrate that wind machines in small villages result in an economically or physically reliable reduction in oil consumption and energy costs. Installation and monitoring of wind data acquisition systems are a necessary first step in quantifying the resource and producing an appropriate systems design. Geothermal energy has not yet proven to be a viable resource in Alaska even though there are numerous sites where geothermal resources have been identified. A major problem with geothermal power is the low temperature of the resource, its remoteness and the high cost of developing and transmitting the potential energy to the user. If a village is located adjacent to a hotspring, the potential for developing the resource is great; if it is 10 miles from an uncertain source the costs of investigation and development are most likely to be prohibitive. Solar energy has not been shown to be an economically realistic source of energy for the majority of rural Alaskan communities. The short hours of sunlight during the wintertime and heavy cloud cover in the summer mitigate against its success. Coal beds occur locally in western Alaska. Some villages gather coal from exposed seams along the rivers and use it as a supplementary source of space heat. No commercial mines operate in the region and as far as can be determined there are no immediate plans for such. Technologies The only long-term proven technology for reliable electrical supply in rural Alaska is that associated with diesel powered generators. Where available the greatest alternative potential lies with small scale hydroelectric developments. Acknowledgement of the role of diesel powered generators makes it incumbent upon the utilities to insure maximum efficiency in the use of diesel fuel. The first step is to size the generators to meet the forecast loads, the second is to incorporate waste heat capture systems which have been proven technologically and economically, and the third 2-4 step is to introduce management techniques to reduce the consumption of fuel without increasing operation costs. 3.0 3.1 METHODOLOGY VILLAGE CONTACT Approaches to the Village Upon the award of the contract, a list was compiled inclusive of the regional corporation, non-profit groups, village Indian Reorganization Act (IRA) councils, village corporation, and municipality officials and individuals who had attended or expressed interest in programs conducted by RurALCAP during a recent study. Itineraries for village visits were established and proposed dates for village meetings were presented. Additionally, officials in each of the villages were contacted by telephone. The purpose of the program and village visits were outlined and the proposed village meeting schedule was verified. A letter was sent to each official in each organization from the Alaska Power Authority. Vagaries of weather dictated final schedule adjustments and telephone contact was made with the village prior to arrival of the field team to advise of any changes in schedule. Work Methods in the Villages On arrival in the village the presidents of the corporation and/or the head of the IRA Council was contacted, the village meeting time and location verified, and the field team received an introduction to the special conditions and concerns of the community. All power plants, stores, schools, public buildings and major commercial concerns were visited. Several houses were also visited and the size, condition, heating systems and appliances were noted. Community meetings were held with advance notice being given over the village CB radios. Discussions during and after the meetings provided the majority of data on the standard of living, the expectations of the people and the plans for developments in the community. Arrangements were made with individuals at the meetings to visit their homes afterwards. Contacts made within the village were noted and any special questions or concerns over the reconnaissance program were answered. Additional information not readily available while the field teams were at the villages was researched in Anchorage and the villagers were subsequently recontacted by telephone. In some cases additional written and published materials were mailed to the village. Community Involvement Community involvement was a priority throughout the project, although it was limited to one visit as it was not possible to schedule return visits for direct discussion of the results and recommendations. Contacts were maintained with several of the villages and where possible additional information was supplied to other agencies after prior approval of the Alaska Power Authority. 3-2 Jed The draft reports were circulated to the villages for their comments prior to submission of the final village specific reports. DATA COLLECTION Data Forms The Alaska Power Authority provided the contractor with a data form which combined aspects of forms developed during previous reconnaissance studies. Sources of Information Prior to visits to the villages a bibliography of data sources was compiled (Appendix A). Information was abstracted and entered onto the forms and data from the census and the utility records were compiled and condensed onto the form. Nine of the villages in the study do not have central generation, therefore additional information was sought for villages of similar populations and levels of economic activity. Background data was aggregated into themes, for example, peak loads, fuel requirements, and diversity factors and then projected and analyzed on a village-specific basis. Data from previous reconnaissance studies was compiled and used for comparisons. Information on costing for alternative plans was collected from previous studies, suppliers, manufacturers, and design/construction groups with experience in rural Alaska. Village Visit Meetings with the village officials and villagers provided much information especially on the use patterns present requirements, expectations and future growth potential in the village. Site reconnaissance enabled the measurement of buildings, detailing local commercial, public and school buildings. Further, these visits were used to record the various aspects of the electricity generation and distribution systems. The data forms were filled in, as far as possible, during the visits to the village. Further data sources were utilized from state and private sources outside the village in the final compilation effort. Further Data Sources Additional information was collected from manufacturers and equipment suppliers for diesel powered generators. This data was used to calculate fuel consumption where precise records were not available. Contact was made with the Regional Housing Authorities and Housing and Urban Development, and other agencies involved directly and indirectly with development plans for the villages, for example, Public Health Service, and the State Department of Community and Regional Affairs. Three field crews were involved in the village visits and subsequent meetings between the groups provided valuable background, corroborative data. Sio3 ENERGY BALANCE CALCULATIONS Methods The energy balance in the village was calculated according to the following procedure. Data on energy consumption was collected from: 1) village corporation records 2) schools (BIA and Regional School Districts) 3) generating facilities 4) major local or regional distributors 5) the residents of the villages during the site visits The principal energy users in the communities were divided into six sectors; these are: 1) transportation 2) electrical generation 3) residential 4) commercial 5) schools 6) public The major end uses were defined as: 1) heating which included cooking and space heating 2) waste heat production 3), electrical generation 4) transportation The data was collected and tabulated. Heating values were calculated to provide a basis of comparison between the values for each sector and end use. Throughout the calculations energy values are expressed in units of MMBTU (Million BTU). Assumptions Record Keeping The level of recordkeeping varies markedly between villages and between sectors. Total energy use values were available for all the villages. However, in certain instances there was no village-specific data for a certain sector(s) and values had to be estimated. Estimations were based on values obtained from villages within the study area which have central generation facilities operated by reporting utilities. Values were also derived from AVEC records from other villages in the region. Schools Records for the school sector were obtained for all villages. In schools that fuel for space heating and electrical generation were not separated the electrical generation consumption was estimated based on the size of the generators, loading, square footage, and comparison with comparable schools where data was available. Other Sectors Estimates of fuel oil use for sectors in villages with inadequate data were derived from the square footage of occupied floor area, type of use, geographic location (which effects, for example, heating degree days), and on a proportional basis using data from communities of similar size and location within the region. Energy Conversion The methods of converting chemical energy (i.e. fuel oil) to useful energy (i.e. heat and electricity) experience varying efficiencies. These are summarized in the table below (Table 3.1). The efficiencies in the table were used to determine the amount of heat energy lost in the energy conversion process. Table 3.1 EXAMPLES OF ENERGY CONVERSION EFFICIENCIES Conversion Efficiency Process to Useful Energy Energy (Heat) Wasted Diesel-electric 18-30% 70-82% Generation Small Fuel Oil 6038 40% Space Heating Equipment (drip oil stoves) Small Wood-Fired 30% 70% Space Heating Equipment Larger Fuel Oil 65-70% 30-35% Space Heating Equipment (oil jet burners) (Schools) The waste heat component of the energy balance is determined by conversion efficiency. Recoverable waste heat estimates are based on typical specifications from manufacturers and field observations of actual operation. 1) Diesel-electrical 65% of the waste heat can be Generations recovered through installation of jacket and exhaust heat exchangers. 2) Drip Oil Stoves 50% of the waste heat can be recovered through installation of high efficiency burners, exhaust 3— i, stack heat exchangers, and improved maintenance. 3) Wood stoves 50% of the waste heat can be recovered by installing airtight woodstoves and exhaust stack heat exchangers. 4) Oil Jet Burners 10% of the waste heat can be recovered by installation of new jets, regular maintenance and the installation of pre heating unit using exhaust heat for incoming aire Energy Balance Data and Calculations In Table 3.2 where fuel use is divided into sectors the total gallons are converted to MMBTU and to a proportion of the total for all sectors. Electricity use in MWH is treated similarly. The power generation sector uses a known number of gallons, expressed as MMBTU, and the proportion of total fuel used in the village. MWH used for generation related equipment, for example, fans, is entered as MMBTU used in the electrical generation sector. MMBTU for electricity use are added to those for the other sectors to give a total MMBTU from electricity in the community. The difference between the MMBTU content of the fuel oil used for electricity is the amount of waste heat produced, of which 65% is assumed to be recoverable. For residential, school and public facilities it is assumed that 60% of the fuel oil energy entering the property is 3=3 used for space heat. Forty percent of the energy in the fuel oil is entered as waste heat, 50% of which is assumed to be recoverable. The total energy used is the sum of the MMBTU in all fuel types minus the waste heat. The proportion of fuel oil used in the commercial sector for space heating was either derived from records or estimates based on comparable commercial operations for which data was available. Waste Heat Calculations The manufacturers of diesel engines, which power electrical generators, provided information for the amount of heat rejected to the engine cooling water for various engine loadings. The rating of the primary generator(s) is divided by the average generator load. The average load is calculated as follows: KW Ave Load = Total KWH generated in one year 8760 hrs. The average load is then divided by the generator rating, to give the percentage of the rating that represents average operation. % Load Rating = Average Load (KW) y 190 Generator Rating (KW) Figure 3.1 presents information, published by Caterpillar, of the percentage of waste heat available as a function of the percentage of the generator rating. The maximum heat WASTE HEAT AVAILABLE MAX, % 100 80 60 40 20 AVAILABLE WASTE HEAT * JACKET WATER = EXHAUST ! 1 ! | i Ta TOTAL AVAILABLE 20 40 % KW LOAD * (DERIVED FROM DATA IN THE Figure 3.1 a 60 80 100 RATING CATERPILLAR CO. MANUAL) NOT AVAILABLE AT EXHAUST HEAT EXCHANGER rejection rate to the cooling water, also published by Caterpillar, was used to calculate the amount of waste heat available at the average operating conditions. Presentation of Information Data for each village is presented in tabular form for each sector by end use in Table 3.2 and as an energy flow diagram (Fig. 3.2). For example, the electrical generation sector uses 2293 MMBTU of fuel oil to produce 603 MMBTU of electricity. 150 MMBTU of this is used by the residential sector, 170 MMBTU by the commercial sector, 170 MMBTU by the schools, 75 MMBTU by the public sector; and 11 MMBTU is used for electrical production. These electrical values are shown on the Energy Flow Diagram under electrical distribution. The balance of the MMBTU input to the electrical generation sector is 1689 MMBTU, which represents the waste heat lost from the diesel generators. The Energy Flow Diagram represents the flow of energy entering the villages as fuels to the designated end uses by sector. Fuel oil is used for space heating and power generation. Both uses contribute to the village waste heat as shown. A proportion of the waste heat produced can be recovered. Within the residential sector some of the heat is lost through air infiltration and heat losses through walls, floor and ceiling. e176 VILLAGE: a ENERGY BALANCE Fueu GIL GASOLINE PROPANE wooo CLEC TRICITY : sii SECTION ee peel GAL ane Los an conus a De is mh fy Ga. aEBe RESIDENTIAL 17500 | 2360 33 44 150 25 944 472 | 1506 33 COMERCIAL 5000 674 10 49 170 28 270 135 574 12 AGITL IC 7000 947 13) 22 75 12 379 | ‘190 643 13 SCHOOLS 5500 TAT ll 50 170 28 299 30 618 13 CUPCTRICAL GENEWATION 17000 | 2293 33 ll 30% 6 1689 | 1097 38 1 TRENSPORTATION 10000 | 1350 1350 20 TOTAL 52000 |7020 100 77 603 |100 | 10000 | 1350 ys82 [1924 | 4789 | 100 *station service or distribution losses Table 3.2 ET=€ Z°€ eandtg ATRAL9N2 Pop: los HOUSEHOLDS: 25 8,500 UTG. OCGREE DAYS Bust quounT ENERGY BRODUG ELECTRICAL eno use 1OTaL a co: SiON enor woOJ00 FUEL OIL (7020) BY SeCcioOR CaAtALICN RESIOLNTIAL TRANSPORTATION COOKING HEATING OISTRIBUTION By SCcy RESIDENTIAL Gee Enka? TOTAL i Iieput ENCRGY (8370) 2360) _ 2 (1566) HEATING/ (1416) (150) COOKING pune (O41) - SS a COMMERCIAL inn - COMMERCIAL . HEATING on (40 (170) | (574) (674) : <~ oe AE 7 eek (G04) a (643) POWER SCTE 7 POWER GEn. a GENERATION ELECTRICAL (2293) GENERATORS nica) (170) esideeattbeid seeds eee, . an omnes cme ee —_ SCHOOL(S) SCHOOL(S) HEATING/ (61k ae COOK IG aoe a sR) (747) (25) _ _ _ PUULIC PUBLIC (643) HEATING (947) WASTE TOTAL HEAL USABLE Ent uGy 5 soe) RECOVERABLE r 3 WASTE MEAT > (1924) (1789) E NEAT Hse chee 1 NON - RECOVERABLE 6 BRACKETS ARE JNGERS IN 10® gtu's. 3.4 PROJECTIONS Population Forecast Historical population data was obtained from the Office of the Census for all villages. The data was graphed and a curve was fitted. Linear models and differential equations were used but a percentage growth model provided the base fit to the majority of the villages and was adopted throughout. Figure 3.3 illustrates the population projections for St. Paul. Capital Project Forecasts The forecasts were based on projects which were detailed to the field team while in the village. Where insufficient information was available, the sponsoring agencies and departments were contacted. During each community meeting the participants were asked if there were other capital projects that were being planned. Where a specific time frame was given, the information is recorded under the village visit section of the village-specific reports. Thermal Energy Use Projections These were based on the continuation of present values expressed as BTU/square foot/capita. Increases in the population were used to calculate an increase in the square footage of building space within each of the sectors and the BTU required to satisfy their space heating needs. Electrical Energy Forecasts The forecasts were based on an established relationship between the amount of electrical power used in a village, the size of the population and the number of square feet POPULATION POPULATION FORECAST FOR ST. PAUL scat il + Ry BCO Fr e 4 x & ¢ ole 709 + v 4 6co F Wy I Mal sco - S 4 Wa 606 F bai “7 © e Par © DATA POINTS 209 - ell I , ! ' ! ! ! ' 1939 1940 1950 1960 1970 1980 19390 2000 2010 YEARS Figure 3.3 3-15 3/15 occupied by each sector. Present electrical use data was analyzed to determine the number of KWH used per square foot in buildings in each sector. Increased usage in all sectors was then based on the increasing population rate. The annual load factor was the basis for projecting the peak demand. ALTERNATIVE SOURCES OF ENERGY Resource Assessments Brief outlines of the resources of the area surrounding the village site were compiled from published information, where available, and for data collected while in the community. Due to its excessive cost, wind as an energy resource was addressed directly for only two represented villages: Nikolski and St. George. The costs per KW installed ranged from $17,000 to $34,000, in comparison to $2000/kKW for a newly installed diesel generation system. Wind systems have been shown, for example at Nelson Lagoon, to be most unreliable. Therefore, the economic, technological and reliability considerations all dictated that wind powered electrical generators are unsuitable for the villages studied. Appropriate Village Technologies and the Criteria for Ranking Resources and Technologies Appropriate technologies were reviewed in order to determine their potential for further consideration on a village specific basis. The potential appropriate technologies are described in Appendix A of the main report. The technologies were "Screened" for each village. 3-16 Screening was based upon the initial assessment of the parameters outlined in the following subsections of this report. Technology State-of-the-Art The availability of system components and their demonstrated application as discussed in the Technology Profile. Technologies available off-the-shelf which meet specific near term needs of the community and match the resource magnitude were rated 5, on the scale of 0 to 5. Those technologies which were not expected to be commercially available for use within 5 years were rated lowest on the scale (0). Some of these technologies will be suitable for demonstration projects within the projected 20-year period of the economic analysis, but it is not likely for rural southwest Alaska will be the appropriate site of each demonstration scalar value of 1 was applied in this instance. Cost Typical system costs were evaluated on a per installed kilowatt or per energy savings basis, in cases of conservation and waste heat capture technologies. Technologies were rated relative to each other for purposes of this assessment. Reliability System reliability and/or continuous or intermittent nature of the resource; sensitivity to supply interruption. Resource Quality, magnitude and availability. The availability of resources for the appropriate technologies to meet energy requirements of the community was anticipated. Labor Level of skill or training necessary to long-term operation and maintenance of the energy system. Environmental Impact Anticipated effects of the technology and its associated resource use on the natural environment. Determinations of individual "scores" were based upon technical input as presented in the Technology Profiles, resource data and experienced judgment. A ranking system was developed to quantify the decision process for determination of best alternatives for each community. The process consisted of averaging all variables and weighting technology state-of-the-art and resource availability factors most heavily. The ranking formula follows: Ranking Factor = (A/30 + B/10)/2 where A = the sum of the (state-of-the-art + cost + reliability + resource + labor + environmental) scores and B = the sum of the (state-of-the-art + resource) scores An example is included for Atka, Table 3.3. Here it can be seen that central diesel generation, the installation of waste heat recovery and hydro-electricity are the "best" technologies for central systems. Weatherization has the 6I-€ Village of Atka Relia- Enyviron- Ranking Technoloyy Factor State-of-the-Art Cost bility Resource Labor mental Tinpact Pee Ak rug: | earreuewrrore cree: Semurrecen rorasie we) ceases wae eT a i er rennin: [oa ee ron conor apr unmew io ae < . ; 6 Fnersy Conservation «ae 5 5 5 5 5 1.00 Diesel Power Waste Heat Recovery Hvdroelectric Power Wind Energy Conversion ys ters Geothermal Energy Steam Power trom local fuel, wood, coal, ctc... 0 0 (0) 0 0 0 0,00 ification of wood, coal 0 0 0 0 0 0 0.00 or peat Generation via synchronous Induction 4 2 2 2 1 3 0.53. Electrical load manayement 5 3 3 2 ] 4 0.63 Simple wire ground return 4 3 2 7 l 3 0.48 rn dt et mes rh ee coe re A NOTE: 0 = worst case, 5 = best case Table 3.3 3.6 highest score and features in the recommendations. However the emphasis of the Reconnaissance Program is electricity production. Criteria for evaluating plans include cost/benefit ratios. Because weatherization is carried out by the individual consumer/household, it is considered that the economic evaluation is beyond the scope of this work. However, energy conservation is included as a recommendation for all villages and it has been assumed that home weatherization will become increasingly common throughout the study region. FORMULATION OF ELECTRICAL ENERGY PLANS The appropriate technology screening and the requests and special preferences of the villages were taken into consideration when formulating all the plans. Base Case Plans Data for existing facilities in the village were compiled. Where central electrical generation was - installed, a business as usual plan was adopted. However, in eight of the villages studied, Atka, Chefornak, Chignik Lake, False Pass, Ivanof Bay, Kotlik, Newtok, and Nightmute, there was no central electrical generation. Central electrical generation is defined as an integrated generation, transmission and distribution system which serves all the connected loads in the village. Within the above 8 villages, existing systems range from individual generators at each house in Ivanof Bay to the school not being connected at Chefornak. The methodology employed to determine the sizing, character and cost of central electrical generation systems is outline below in Section 4. Alternative Plans Plans are presented which are based on the premise that the recommendations will be followed up immediately. The electrical supply system in the village is at a critical threshold, costs are high, efficiency is low and the villagers see a reliable supply of electricity as basic to the maintenance of the viability of the village. Screening appropriate technology options suggested that in several villages conservation measures were the only options. In others, alternative sources of power for electrical generation were available, primarily hydropower and wind power. The plans were reviewed by the Alaska Power Authority and where only one plan was presented, it was acknowledged that there was no other realistic plans possible at this point in time. However, where there were indications that two potentially viable alternative plans could be presented, they are detailed and included. Cost estimates are based on existing installations or other published cost estimates for comparable projects. Where no parallels were found preliminary designs were prepared and cost estimates were based on manufacturers published price lists. Every effort was been made in the preparation of the cost estimates although it is recognized that minimal supportive data is available from all the villages considered. It has been assumed that, for example, generator buildings have sufficient space and structural support to permit the installation of waste heat equipment. For those villages where hydro power appears to have potential, the absence of geotechnical data means that road 3.7 and dam construction estimates have to be based on restricted site visits or experience in the area and the estimates should be treated more as guidelines until the foundation conditions are ascertained in the field. PLAN EVALUATION Plan evaluations have been based on the present worth of the electrical generation system. Where there are non-electric benefits, for example space heat from waste heat capture systems, the heat (MMBTU) has been offset against fuel requirements (MMBTU). The benefits were then discounted to give the "discounted net non-electrical benefit". Present Worth Calculations A current value was estimated for the power generation equipment installed in a village based on comparable systems in rural Alaska. For the "non central generation villages" cost estimates for the power generation items were included. Equivalent uniform annual cost techniques were employed as the basis for the amortization schedule which was initiated for each new generator and added to the annual amortization costs. The plan costs were discounted annually and the total discounted plan cost was determined. For those plans which focused on hydroelectric power development only that power produced needed to offset the projected village demand for electricity use was included. The installation of a waste heat capture system results in a reduction of the fuel oil requirements for space heating. Heat captured and redistributed as space heat offsets fuel ause 3.8 oil normally used for space heat. It is recognized that use of excess electrical power from hydro plants for resistance heating would reduce fuel oil requirements of the village. However, this was not included as a non-electric benefit. RECOMMENDATIONS Recommendations were based on the economic analysis of each plan. They include estimates of the costs for feasibility and/or design studies. In situations where wind is a potential resource monitoring programs have been recommended. Weatherization is regarded as basic and has been included as a recommendation for all villages. 3-23 4.0 CRITERIA EMPLOYED TO DETERMINE THE PRESENT DEMAND, ENERGY USE AND COSTING FOR THE INSTALLATION OF CENTRAL GENERATION SYSTEMS IN THE VILLAGES Methods Reconnaissance level designs and cost estimates for centralized power distribution systems were made and constitute the base case plan for the eight villages. In cases where heat recovery from the diesels was possible, a generating site was recommended which would facilitate installation of heat recovery equipment. Each village was visited and data was gathered on the electrical equipment found in typical residences, schools, commercial buildings, and public buildings. Several of the villages without central generation were found to be similar to those served by Alaska Village Electrical Coop (AVEC). AVEC data was obtained for a number of villages of similar population and this data was analyzed to determine typical use values to establish estimates or corroborate existing data. [In villages with a dynamic fishing-based economy typical households necessary are equipped with electrical loads in excess of those of the other villages. In these cases, estimates were based on the electrical equipment installed in the homes and information from residents concerning their future requirements. Diversity factors, typical of small residential communities were used when sizing electrical distribution systems. Village electrical consumers were divided into four categories as follows: Wis Residential Qe Schools 3 Public 4 : Commercial In all villages, each of these four sectors was examined and an estimate of the power consumption by each sector was made. Each of these four sectors are discussed below. Residential In villages where detailed records were not available, AVEC data was used to compute electrical consumption per household and per person. These values were used for power usage estimates in the villages of Newtok, Nightmute, Kotlik, Atka and Chefornak. In the villages of False Pass, Ivanof Bay and Chignik Lake, site visits revealed higher connected loads. The residential monthly power consumption for these villages was based on the appliances installed in a typical home and known power consumption for these types of appliances (derived from industry standard tabulations). In villages where peak demand factors were not available, they were calculated from village-specific data and were used to predict peak demand in Newtok, Nightmute, Chefornak, Atka and Kotlik. For the other villages, the ratings for the household appliances were added to determine the total connected load of each house. Diversity factors were then applied to take into account the fact that not all appliances are used to any one point in time within a single house or group of houses. The peak demand for these villages was then calculated. This technique is widely used for predicting peak demand for small, residential communities. Schools The schools in all the villages in the study were similar in their power requirements. Consumption factors for KWH/mo/£t2 were calculated. A range of values was used depending on the age of the school buildings and their condition. It was noted that new schools tend to have lower requirements than older schools. Peak demand factors were calculated for schools with complete records. Peak demand in a school occurs typically between 10:00 a.m. and 2:00 p.m., a period when residential power use is low. Residential peak demand tends to overshadow school peak demand, and sets the peak demand for the system. Public Public buildings in the villages surveyed consisted generally of a community center, Alascom Communications System Facility, a small clinic, and in some cases, a water treatment and distributionsystem installed by the Public Health Service. Review of data from villages of similar population to the study villages indicates that the public sector typically uses between 6 and 12% of the total energy. In some cases, this was as high as 18% in villages that had extremely low residential power usage. After calculations were made of other consuming sectors within the villages, use in the public sector was calculated and expressed as a percentage of the total. Judgment factors based on the field team's knowledge of the villages were included to estimate the proportion. Commercial It was impossible to identify trends for power use in the commercial sector. In most of the villages studied, the 4.2 Major commercial activity was a village store which was considered separately. Historical data was used to estimate power consumption and peak demand for stores in the villages. Total Energy used and Total Peak Power Estimate The total monthly power consumption in the villages is the sum of the power consumption of the four sectors. LAn additional 10% was added for unaccounted losses and power plant overhead when these were not recorded explicitly. Peak demand was largely set by the estimated peak demand of the residential sector. However, in some cases, judgment was applied to increase the peak demand appropriately when it was felt that other sectors would overlap the residential peak demand period and cause an increase. The Annual Load Factor was calculated for each village sa follows: A.L.F. = Yearly KWH 8760 x Peak Demand KW The A.L.F. of the villages studied, based on the estimated consumption and peak demand figures, varied between 0.3 and 0.5. This compared favorably with historical AVEC utility figures for A.L.F. which range between 0.3 and 0.6. Generator sizing is based on the estimated peak demand with a reasonable excess to allow for village growth and increased electrical use by the village residents as new types of appliances are installed. 4-4 4.3 Costing An example of the costs for the system at Chignik Lake follows (see Table 4.1). All cost estimates were based on published prices by major suppliers. Labor has been estimated based on Davis-Bacon rates, i.e. union rates for work in remote communities. COSTS WH generated with heat recovery equioment ALCULATED VALUES Average Generation Rate Percent of On-Line Capacity Maximum Jacket Water Heat Recovery Percent Jacxet Water Heat Available Estimated Recovered Heat Available Estimated Recovered Heat Utilized MAJOR COST ITEMS ile Main piping 959 feet x $150/it Ze Heat Becovery Equipment 3. Circulating Pumps Ae Heaters and Miscellaneous Hardware S. Total Project Cost 6. O and M Cost (1090 KN _on line) ($20)(1x%106) Chignik Lake 100,100,50 294,000 100,100,50 34 kw 34 8 (5200 BTU/MIN 43 3 .134x10° BTUH _.134x10° BruH $_37,500 ___ 47,900 10,800 31,000 127,200 (_.134% 106 BTUH) (3760) $1.70/MMBTU Recovery Effici .134x10° e ncy . BTUH x 8760 hours/ 294,000 Table 4.1 KWH ESTIMATED HYDRO COSTS Project Location Flow (cfs) Head (ft) Transmission Line Length (miles) Road Length (miles) CALCULATED VALUES Average Power (KW) CHIGNIK LAKE-Basin #5 125 KW CFS 114 kw Energy Available @ 303 Plant Factor (KWH/yr) 328,500 Pipe Size (inches) Head Loss (ft) MAJOR COST ITEMS Ie Power Plant 125 KW x $ 1000 /KW 14 in. 120 ee 125,000 2. Diversion Structure 1 UL00 7 000.) 3h Water Way (Penstock) 2750 ft x $ 80 /ft_ 220,000 1] 4, Transmission Line 1.8 mi x $90,000 /mi 162,000 Ss Access Road 4 mi x $50,000 /mi__ 200,000 6. Mobilization and Demobilization 350,000 We Base Cost ri) 8. Project Management (5%) 9s Test and Energization (5%) 10. Engineering (10%) 11. Contingencies (203%) 12, TOTAL PROJECT COST Table 4.1 (Cont'd.) 1,157,000 58,000 1111) seem 116,000 232,000 1,621,000 5.0 SUMMARY OF FINDINGS Twenty villages in western Alaska, southwestern Alaska, and the Aleutian Islands were studied. As shown on Table 5.1, the costs of fuel and power are substantial. For example, fuel costs of $2.33 per gallon translate to about $17 per MMBTU for space heating. Further, electricity costs at $0.4829 per KWH translate to about $140 per MMBTU for electric power. These costs are high and also do cause financial concern to many residents. The cost and reliability of electrical power supply are also of vital interest. The majority of villages in the Yukon-Kuskokwim Delta region are reliant on diesel generation of electrical power and there are no technologically viable options available. Therefore, the energy plans for the villages emphasize increasing the efficiency of fuel use to help reduce future increases in energy costs. The plans for each of the villages are summarized in the following Table 5.2 (Summary Findings). VILLAGE ENERGY COSTS Village Aniak Atka Che fornak Chignik Lake Cold Bay False Pass Hooper Bay Ivanof Bay Lower and Upper Kalskag Kotlik Mekoryuk Newtok Nightmute Nikolski 1981/82 Residents Electrical Costs 34.5¢/KWH Min. Charge - $25 $60/mo +12¢/KWH 25¢/KWH Min. Charge - $50 Non-Central Average 22¢/KWH Non-Central 21.34¢/KWwH2 Non-Central 21.34¢/KWH2 Non-Central 21.34¢/KWH2 Non-Central $85/mo/household 42¢/KWH Min. Charge - $45 Table 5.1 1981/82 Fuel Oil Costs Electrical Residential Generation Space Heat 5=2 Table 5.1 (Cont'd.) VILLAGE ENERGY COSTS 1981/82 Residents Electrical Electrical Costs |! Generation St. George|14¢/KWH3 St. Marys |21.34¢/KWH2 St. Paul 14¢/KWH3 Toksook 21.34¢/KWH2 Bay Tununak 21.34¢/KWH2 lest imated prices 2AVEC villages Base Cost 37.20¢/KWH Surcharge 11.07¢/KWH Total Cost 48.27¢/KWH Power Cost Assistance -26.93¢/KWH 21.34¢/7KWH 3NMFS Power Plant 5-3 SUMMARY FINDINGS Continueé operatiol$12,790,001 Table 5.2 tor plant 3 BASE CASE ah VILLAGE oz =— TOTAL TOTAL TOTAL 3° PLAN OrscounTEeo PLAN DISCOUNTED PLAN DISCOUNTED = DESCRIPTION PLAN cosT DESCRIPTION PLAN COST DESCRIPTION Puan Cost (19u2 - 2001) (i982 - 20000 (1982-2001) 385] Continued operation}7,616,000 ators. $5,135,000 of diesel genera- ating with tors ste heat recoyv= 108] Installation and 31,616,000] tlydroelectric plant] $1,000,004 Diesel generators $875,000 operation of a ceif- with diesel gener- operating with tral diesel gener ator backup waste heat recov- ator plan ery Che fornak 230] Installation and 32,643,000] Dicsel generators $1,866,004 operation of a central diesel cenerator plant Chignik Lake | 150] Installation and $2,434,000] Diesel generators $1,995,004 Hydroelectric plant operation of a operating with with diesel gen- central diesel waste heat recov- erator backup generator plant ery Cold Bay 200 Diesel generators |[311,207,00} Coal-fired genera- 518,705,00P RECOMMENCATIONS Tnitiate a feasibility stady for waste heat recovery Tavestigate potential tor inproved Generation effin ciency Initiate weatherization program in community Install central diese] generators Initiate a feasibility study for waste heat recovery Initiate a feasibility study including stream gauging for hydroelectric plant Initiate weatherization pro- gram in community Install central diesel gen- erators Initiate a feasibility study for waste heat recovery Investigate potential for improved generation et fi- ciency Initiate wind tion program data acquisi- Install central diesel gen- erators Initiate a feasibility study including stream gauring for hydroelectric plant a feasibility study p waste heat recovery Initiate weatheri gation pro- gram in community Initiate feasibility study for waste heat recovery Investigate potential for im- proved generation ef ficiency Initiate weatherization pro- gram in conmuni ty VILLAGE 1962 POPULATION DISCOUNTED DISCOUNTED DISCOUNTED SUMMARY OF RECOMMENDATIONS DESCRIPTION DESCRIPTION DESCRIPTION PLAN COST PLAN COST PLAN COST (1982 - 2001) 213,123,00(f Diesel $10,158,00 generators operating with recov- Continued operation diesel $13,638,00 514,378,00{ Diesel generators operating with proved efficiency to generation Continued operation of diesel genera- tors with waste heat recovery 1. Design and construct waste heat recovery 2. Investigate potential for improved generation ectti- ciency 1. Initiate design of automatic load matching system 2. Initiate weatherization program in community management $907,000 Transmission line Continued operation |§2,863,000 of diesel Diesel generators operating with heat recov- Tcksook Bay genera- $1,557,000] Intertie from Tok- sook to Tununak with diesel erators operating in Toksook $2,360,000} Diesel gencrators operating with waste heat recov- Continued operation of diesel Tununak genera- Table 5.2 (contd. ) 1. Initiate a feasibility study for waste heat recovery 2. Initiate a feasibility study for transmission line inter- tie 3. Investigate potential for im- proved generation efficiency 4. Initiate weatherization pro- gram in community 5. Initiate wind data acquisi- tion program 1. Initiate a feasibility study for waste heat recovery 2. Initiate a feasibility study for transmission line inter- tie 3. Investigate potential for im- proved generation efficiency 4. Initiate weatherization pro- gram in conmunity 5. Initiate wind data acquisi- tion program 9-S VILLAGE Nekoryuk Newtok Nigh mute Nikolski Georue 174 Continued operation of diese) genera- tors $1,960,000 13] Installation and $1,609,000 operation of a central diesel generator plant 119 Installation and Operation of a central diesel generator plant $1,444,000 5U Continued operation]$1,096,000 of diesel genera- tors 174 Continued operation of diesel genera- tors $2,796,000 Diesel generators operating with e heat recov- ery Diesel generators operating with waste heat recov- ery Diesel generators operating with waste heat recov- ery 10KW wind turbine generator opera- ting with diesel generators Diesel generators operating with fully inplemented waste heat recov- ery $ $ $ $ 1,502,000) 1,088,000) 1,020,000 1,600,000 20-2KW wind turbine generators inter- faced with the local utilities diesel generators Table Sia2, (contd) 3 BASE CASE PLAN A PLAN B = a4 -a TOTAL TOTAL TOTAL 3 PLAN OISCOUNTED PLAN DISCOUNTED PLAN DISCOUNTED = DESCRIPTION PLAN COST DESCRIPTION PLAN COST DESCRIPTION PLAN COST (1982 - 2001) (1982 - 2001) (1982 - 2001) $3,820,001 SUMMARY OF RECOMMENDATIONS Initiate a feasibility study for waste heat recovery Investigate potential for in proved generation efficiency Initiate weatherization pro- gram in conmunity Initiate wind data acquisi- tion program Install central diesel gen- erators Initiate feasibility study for waste heat recovery Initiate weatherization pro- gram in conmunity Initiate wind data acquisi- tion program Install central diesel generators Initiate a feasibility study for waste heat recovery Initiate weatherization pro- gram in community Initiate wind data acquisi- tion program Investigate potential for improved generation ef fi- ciency Initiate wind data acquisi- tion program Initiate weatherization program in conmunity Initiate a feasibility study for waste heat recovery Investigate potential for improved gencration cffi- ciency Initiate weatherization pro- gram in community VILLAGE False Pass Hooper Bay Ivanof Bay and Kal- Lower Upper skag Kotlik 1962 POPUL TION BASE CASE PLAN A TOTAL DISCOUNTED PLAN COST (1982 - 2001) PLAN DESCRIPTION PLAN DESCRIPTION $1,063,000] Diesel generators operating with waste heat recov- ery Installation and operation of a cen tral dicsel gener- ator plant Continued operation of diesel genera- tors $5,487,000] Diesel generators operating with waste heat recov- ery Installation and operation of a central diesel gen erator plant $879,000 Diesel generators operating with waste heat recov- ery Continued operation] $2,882,000] Diesel generators of diesel genera- tors operating with waste heat recov- ery Installation and operation of a central diesel generator plant $3,729,000] Diesel generators operating with waste heat recov- ery Table TOTAL DISCOUNTED PLAN COST PLAN DESCRIPT (1962 - 2001) §1,020,00 $3,184,00 $2,297,000 O} Nydroelectr with diesel ator backup 0 ly droelectri with diesel ator backup $2,825,000 52) (contd. ) ton c plant gene r- c plant gener- TOTAL DISCOUNTED PLAN COST (1962 - 2001) $2,085,00' $779,000 SUMMARY OF RECOMMENOATIONS Install central diesel generators Initiate feasibility study for waste heat recovery Initiate weatherization pro- gram in community Initiate feasibility study for waste heat recovery Investigate potential for im- proved generation ef ficiency Initiate weatherization pro- gram in conmunity Install central diesel erators Initiate feasibility study including stream gauying Initiate weatherization pro- gram in conmunity gen- Initiate feasibility study for waste heat recovery Investigate potential for im- proved gencration efficiency Initiate weatherization pro- gram in community Initiate wind data acquisi- tion program Install central dicsel ators Initiate feasibility study for waste heat recovery Initiate weatherization pro- gram in conmunity gener- APPENDIX A TECHNOLOGY PROFILES Al. Energy Conservation A2. Diesel Power Technology A3. Waste Heat Recovery from Diesel Generators A4. Hydroelectric Power AS. Wind Energy Conversion Systems A6. Geothermal Energy A7. Steam Power Generation from Coal/Wood/Solid Waste/Peat A8. Gasification of Wood, Peat or Coal A9. Synchronous, Induction or DC Generation Systems A10. Electrical Generation Management All. Electric Power Transmission - Single Wire Ground Return (SWGR) Al.0 ENERGY CONSERVATION Al.1 General Description Energy conservation implies the more efficient use of available energy resources. Conservation can take the form of reducing losses in the energy system, such as losses through walls, windows and air infiltration in a home or by reducing losses ina conversion system, such as an oil burner bv improving the combustion efficiency. Al sa Thermodynamic and Engineering Processes A) Homes can be made more energy efficient by reducing heat loss through poorly insulated surfaces and by reducing the air infiltration into the buildings. Methods include improved construction to reduce air infiltration through standard walls, increased insulation thickness, double or triple pane windows and storm windows, reduced window area and improved seals on doors and windows. B) Combustion efficiency can be improved by reducing the amount of excess combustion air and the temperature of the stack gases. A significant improvement in oil combustion efficiency has been made in the "flame- retention" burner. Brookhaven National Laboratory under research spensored by U.S. Department of Energy has determined that potential fuel saving from these improved burners is as follows: 1) The percentage reduction in fuel use ranges from 5% to 22%--with an average annual fuel saving of 14%--by replacing the old burner but keeping the furnace or heater. This 14% figure is corro- Al.1 2) Bailia2 borated by a recent field test of 94 homes where a flame-retention device was substituted for the older burner. Combustion temperatures achieved by a flame- retention burner will be 100°F to 200°F higher than in one of conventional design, if other conditions are kept constant (oil firing rate, air-to-fuel ratio, and configuration of the combustion chamber). This is due to the swirling pattern created by the specially designed head, which confines the flame to a smaller zone in the combustion chamber and concentrates the heat. The hotter flame brings combustion gases to a higher temperature, enhancing the transfer of energy at the heat exchanger. The improved mixing of oil droplets and air, resulting from greater turbulence, permits the unit to use relatively little air and yet com- pletely burn all the fuel. Flame-retention burners generally operate with 30-50% excess air, compared with 80-100% required by conventional burners. With less dilution from excess air, combustion gases stay hotter and move slower through the heat exchanger, which means better radiant energy transfer and higher burner efficiency. Technology Availability The technology of energy conservation in homes is available today and has heen available for years. The forcing function to promote this technology is the cost of heating oil. Figure Al.1l is a graph of the estimated fuel consumption for a poor and Al.2 well insulated heme in the western Alaska region where degree days vary from 12,000 to 14,000°F days per year. The actual oil consumption for homes in Western Alaska is approximately 40-50% greater than required for a well-insulated home. Demonstration of this technology is wide spread on a small scale and can be found in many areas of the country. The flame retention oil burner is readily avail- able from several manufacturers either as a retro-fit to an existing furnace or as part of a new furnace. Most oil heating equipment dealers have flame retention oil burners on hand for immediate supply for retro-fit. Al.2 Performance Characteristics Al.2.1 Energy Output A) Quality The quality in energy conservation is improved comfort of the home and reduced cost for that comfort. B) Quantity The quantity of energy available from home conservation in western Alaska appears to be quite significant in the area of 30-40% of the current consumption. Cc) Dynamics Not applicable. Al.3 Fs B22 A) Reliability Need for Backup There is no need for back-up for improved energy utilization in the home. B) Storage Storage requirements of energy in the village is reduced. AL eizielS) Thermodynamic Efficiency Both conservation techniques of reducing energy losses and improving combustion efficiency will increase the overall efficiency in the use of valuable resources. Costs for Typical Unit Asie A) B) Capital Costs Estimated capital costs for various levels of insulation in a new home are shown in Figure Al.2. Labor cost for installation of increased insulation thickness should be about the same regardless of the cost of the insulation. Estimated cost for the flame retention burner substituted for the conventional burner is $250 to $400 (September, 1979, lower 48 prices) for the average home heating unit. For larger oil-fired furnaces such as found in schools, costs will be higher. Al.4 Al.4 Rleeesrer2 Assembly and Installation Standard home construction methods apply to installation of high insulation values and reduced infiltration. Instal- lation of the flame retention oil burner requires a service- man. Because this burner produces a much hotter flame, the combustion chamber should be inspected to determine whether or not a chamber lining is required. Where the combustion chamber needs to be rebuilt or replaced, pre-cast combustion chambers of appropriate materials are also available from several manufacturers. Als .3 Operation and Maintenance No increase in the maintenance cost will occur as a result of improved insulation design. Operation will be much more efficient. DS) 4 Cost per KW Not applicable. DTS ao Economy of Scale Not applicable. Special Requirements and Impacts Baa al Siting Not applicable. Al.5 Al.5 Al.4.2 Resource Needs Energy conservation in homes will require increased use of insulation and slightly increased cost of the homes to accommodate the increased amount of insulation required. Al.4.3 Construction and Operating Employment by Skill Once the design information is provided the carpentry and home construction skills exists in the villages. The installation and start-up of the flame retention oil burner in school or home will require a heating contractor or oil furnace serviceman. A1l.4.4 Environmental Residuals None. Al.4.5 Health or Safety Aspects The health within the village should be improved by improved comfort in the home and reduced combustion of hydrocarbon fuels in the region. Summary and Critical Discussion Al.5.1 Cost per MMBTU The additional cost for the higher level of insulation in the new homes would be offset in the first year by reduced heating costs based on oil at $1.50 to $2.25 per gallon. The payback for the retention head oil burner is estimated by Brookhaven National Laboratories to be 1 to 5 vears depending on the length of the heating season and the cost of oil. No figures have been estimated for the cost per million BTU because of the wide variation of conditions. Al.6 Al.5,.2 Discussion Energy conservation offers the best opportunity for reduction of oil consumption and energy costs to the villages studied. It requires that improved design of homes in remote sites be provided and that a full understanding be brought to the villages of how energy is lost through building walls, windows and cracks, so that construction is completed to achieve the goal of reduced energy consumption. Once installed properly these technologies have the highest reliability, the greatest availability and are most appropri- ate for the area involved. It is recommended that the first effort towards reduced energy cost in the villages be toward developing an energy conservation ethic. That is educating the villagers on what is an energy efficient home and how to achieve it without significant change in the way of living. Once this ethic is established, other areas such as electrical energy conver- sion will be understood. Aled (GALLONS) ANNUAL FUEL OIL CONSUMPTION 2000 1750 1500 1250 1000 750 500 250 RESIDENTIAL YEARLY ENERGY CONSUMPTION = 14,000 °F - 0aYS 4 NO INSULATION 12,000 °F-DAYS WELL - INSULATED 10,000 °F - DAYS | 14,000 °F-DayYS 12,000 °F-DAYS 10,000 °F - DAYS ° 200 400 600 800 1000 1200 FLOOR AREA OF RESIDENCE (SQ. FT.) Al.8 MATERIAL COST OF FIBREGLASS INSULATION $350 $300 $250 $200 $150 $100 “$50 Fig. Al.2 200 400 600 800 1000 TOTAL INSULATION IN SQUARE FEET Estimated Capital Costs for insulation in a new home. Al.9 A2.0 DIESEL POWER TECHNOLOGY A2.1 General Description Electric power in western Alaska village is typically produced from diesel driven generators. Sizes of these generator units range from one or two kilowatts for individual dwellings to 600 KW or more for central station use. Most of the engines are the liquid cooled, four stroke cycle type with or without turbo- charging. Air-cooled engines are also in use, and two-stroke cycle diesel engines are available. A2.1.1 Engine Cycles Diesel engines are either a two-stroke or four-stroke operation. In a two-stroke engine, air compression occurs in the cylinder as the piston moves upward, fuel is injected near the end of the compression stroke and ignition occurs driving the piston down. The cylinder is then purged of combustion gases for the start of the next stroke. One crankshaft revolution is required for each power stroke on two-stroke cycle engines. Two crankshaft revolutions are required in a four cycle engine for each power stroke. The compression and power strokes take place in the first revolution while gas exhaust and air intake takes place in the second revolution. Four-stroke engines usually have a higher efficiency and consume less lubricating oil than the two-stroke engines. Two-stroke cycle engines are more compact, lighter weight and faster accelerating in comparison with the four-stroke engine at the same power rating. These advantages favor its use for mobile applications such as trucks. The use of four-stroke diesel engines to drive stationery electric generators predominates over other engine types in Alaska. A2.1 A2.2 BA) 51 ai Turbocharging A small gas turbine compressor driven by exhaust gases can be added to a diesel engine to increase the air pressure at the beginning of the compression stroke. More air is then available for combustion and the engine power and efficiency are increased. Turbocharging can also reduce smoke and pollution emissions. Internal engine components such as valves run cooler when an aftercooler is added to cool the air from a turbocharger. An aftercooler uses the engine coolant liquid to cool the air before it enters the cylinders. The cooler engine results in longer engine life. Most new diesel generator units rated above 100 KW include turbochargers as standard equipment. A2.1.3 Current and Future Availability Diesel generators are readily available in all size ranges required in Western Alaskan villages, with future availa- bility assured. Performance Characteristics AQ. 2.51 Energy Output A) Quality The larger diesel engines are liquid cooled with the liquid pumped to external radiators to dissipate the heat to the air. Radiator fans are provided to increase the air heat transfer rates. The fans are driven from the engine shaft or by an electric motor when the radiator is installed at a separate location A2.2 away from the engine. Glycol mixed with water is used as the coolant to prevent freezing during cold weather. Smaller diesel engines (under 125 KW) may be air cooled. These engines have simpler construction and lower cooling system energy consumption than the small sized liquid cooled engines. Maintenance is also simpler because of the elimination of liquid system effects such as leakage, corrosion, cavitation and need for antifreeze protection (glycol). Waste heat recovery is limited from air cooled diesel engines. The heated air may be ducted to an adjacent room for space heat purposes. More remote use is restricted because of large heat losses in air ducts over long distances and blower limitations. Waste heat recovery from liquid cooled diesel engines is con- siderably more practical and economical, as described in Section A3 of the report. B) Quantity Approximately 30% of the input energy is converted to electricity, and approximately 50% of the input energy could be reclaimed from a liquid cooled diesel engine. The percentage of the recoverable heat increases slightly as the diesel engine output is reduced from its design capacity. Cc) Dynamics The output would be a function of the electrical energy demand on the system. A2.3 A2..2.2 Reliability Diesel generator units are expected to operate 20,000 to 50,000 hours (4 to 10 years) before needing a major overhaul when they are properly operated and maintained. The major overhaul work usually includes replacement of bearings, cranks and cylinder sleeves with new parts. A) Need for Backup A minimum of three diesel generator units are required for reliable central station operations in the villages of western Alaska. Two of these units are sized somewhat larger than the peak demand to allow for growth of village power requirements within the life expectancy of the generator units. A third diesel generator is sized to operate efficientlv at the lower summer demands while also serving as a standby unit for use during switching operations of the larger units. B) Storage Requirements Sufficient storage of fuel oil, lubricating oil and other lubricants is required to last as long as the longest period between fuel deliveries. B22 2ied Thermal Efficiency The thermal efficiency of a diesel generator unit depends on the compression ratio and excess air in the engine cylinders during operation, as well as the heating value of the fuel. Typical thermal efficiencies at rated load range from 30 to 32 percent (including electric generator efficiencies) for turbocharged unit sizes above 200 KW. Smaller size diesel generator units have lower efficiencies which range down to 27% at the rated load. A2.4 Agus The partial load efficiency of a diesel generator remains near its efficiency at full load, down to approximately 60%. At loads less than 60% the efficiency drops off signifi- cantly. Manufacturer data usually are not provided at less than 25% of engine rating. The generator efficiency follows a similar trend as the diesel engine. Costs for Typical Unit Installed AZ eB ie Capital The curve shown on Figure A2.1 indicates the capital costs for diesel generator unit sizes from 25 KW to 200 KW. Other capital costs include fuel storage and generator building. Agstee Assembly and Installation The assembly and installation of each diesel generator unit at the site is estimated to require from 4 to 8 manweeks when the village distribution system has been previously installed and operated. The cost of hook-up materials and shipment would be added to the labor costs. At $800 per man day labor rates, the total estimated assembly and instal- lation costs for the size range shown would be $25,000 to $50,000. AZesios Operation and Maintenance Gooc operations include careful attention to lubrication schedules and filter maintenance along with slow warm-up and cooling periods. Partial loads should remain above 25% of the full load rating. Annual operation and maintenance costs are estimated to be $20,000 per diesel-generator unit for the sizes shown in Figure A2.1. A2.5 A2.4 A2.3.4 Cost per KW Installed —— The estimated capital cost per kilowatt installed for each diesel generator unit is $500 to $900. A213 55 Economies of Scale For the sizes of diesel generator units shown in Figure A2.1, the approximate relationship of capital cost to scale is a 44 percent reduction in cost for 400 percent increase in size rating. Special Requirements and Impacts A2.4.1 Siting Waste heat recovery requires a diesel generator location near a heat application. A2.4.2 Resource Needs The fuel for a diesel engines is non-renewable. A2.4.3 Construction and Operating Employment by Skills Construction requires piping and electrical wiring instal- lation skills and knowledge of diesel generator instal- lation. Operation requires a knowledgeable diesel engine and power station technician. A2.4.4 Environmental Pesiduals A) Smoke and other diesel engine emissions need to be minimized by proper control operations. A2.6 A295) B) Used crankcase oil should be disposed of in a space heater. A2.4.5 Health or Safety Aspects No siqnificant effects. Summary and Critical Discussion A2.5 <1 Cost per KWH The cost of electric power production from a central diesel generator system at Alaska villages is estimated at 30 cents per KWH based on $1.50 per gallon fuel cost and a 20 year equipment life. When the electric power distribution and administrative costs are included the cost becomes 45 cents per KWH. A2.5.2 Critical Discussion of Technology Diesel generators are a well established technology for Alaska village electric power. Other possible types of electric power systems are not presently economical or feasible. AZ.7 8° CW T°7w eaznbtg - DOLLARS COST/ UNIT 40,000 35,000 30,000 25,000 20,000 15,000 GENERATOR UNIT COST CURVE 25 50 75 ! 100 125 GENERATOR SIZE KW 150 175 200 12 -0 WASTE HEAT RECOVERY FROM DIESEL GENERATORS A3.1 General Description The typical diesel generator converts about 30% of the input fuel energy into electricity. Approximately 35% is removed in the exhaust gases, 30% in the cooling jacket/radiator and 5% from radiation as shown in attached Figure A3.1. Approximately 50% of the heat energy input to a diesel engine is recoverable. The basic method available for recovering this heat is to transfer the heat through heat exchangers to a circulating water or glycol system for use in heating buildings, schools or hot water. The two forms of heat (jacket water and exhaust) rejected from the diesel engine can be recovered in heat exchangers which transfer the heat energy into a fluid such as glycol (see Figure A3.2). The glycol can then be circulated to the schools, to the public health service for water heating or to buildings within economical distances of the generating plant. The system would require recovery heat exchangers and a circulating system. The primary heat exchanger for the engine jacket coolant would be a liaquid to liquid type. An optional gas to liquid type heat exchanger would be added to recover engine exhaust heat. 2.3.2 Performance Characteristics ykevoyeul Energy Outputs A) Quality A heat recovery system can achieve temperatures in the order of 165°F in a properly designed heat transfer system. This is a typical temperature in hot water heaters. ASnn B) Quantity Approximately 50% of the input energy could be reclaimed from a diesel engine. The percentage of the recoverable amount would increase slightly as the diesel engine output is reduced from its design capacity. (See Figure A3.3) Cc) Dynamics The output would be a function of the electrical eneray Gemand on the system. Heat generated in the summer may have to be rejected because of a lower level need for heat at this time. A fan cooled radiator would be connected to the heat recevery system for this purpose. A3.2.2 Reliability and Storage A) Reliability Reliability of these systems can he made very high by duplicate pumps for circulating the heat transfer mecium through the system. Some existing standby heating systems could be removed as the reliability is proven in the village. B) Storage Requirements No storage is required. A3,2.3 Thermodynamic Ffficiency The heat recovery system has a potential of increasing thermcdynamic efficiency of the power generation system from 30% te 60%. IF 50% of the heat can be utilized for water or A3.2 space heating then 50% of the heat input to the diesel engine would be charged to power generation, raising overall power generation efficiency to approximately 60% compared to 20% without heat recovery. A3.3°Cost for Typical Unit Installed The heat recovery system consists of a liquid to liquid heat exchanger to capture water jacket heat and a gas to liquid heat exchange to recover heat from the exhaust gas. In addition, there will be an expansion tank, a circulating pump, piping controls and heat exchangers or radiators at the point of use of the heat. The following is estimated cost of heat recovery on a 150 KW diesel generator. A) Capital Items Heat exchangers $25,000, pumps $3,000, piping approximately $75 per foot, radiator and heat recovery exchangers another $10,000, controls approximately $4,000 plus assembly and installation. The heat exchangers would be installed in existing buildings where the generators are located. Main piping would be 2" to 3" steel and fiberglass, insulated to carry the glycol from the generator to the location where the heat would be used. Radiator and heat exchangers will be installed at the point of use such as a school. Esti- mated total equipment and installation costs are $100,000, when the distance between the heated buildings and power plant is approximately 300 feet. B) Operation and Maintenance Upkeep of the pump and cleaning of the heat transfer service will be necessary to maintain the efficiency. The gas to liquid heat exchanger on the engine exhaust requires exhaust » R323 A3.4 gas operation temperatures at 400°F or above to minimize corrosion effects. Also, the water or glycol within this heat exchanger must be drained when it is not used for heat recovery. Cc) Cost per KW Installed Not applicable. D) Economies of Scale Not applicable. Special Requirements and Impacts AS 4rd Siting The technology requires a waste heat source near a heat consumer. A3.4.2 Resource Needs A diesel generator of suitable size for economic energy recovery which is at least 75 KW would be the heat source. The diesel fuel is non-renewable. A3.4.3 Construction and Operating Employment by Skills Construction requires piping and weldirg skills and know- ledge of designs and installation of the piping and equip- ment supports. Operation requires a knowledgeable pump and heating unit technicien. A3.4.4 Environmental Residuals None. A3.4 A3.5 A3.4 35 Health or Safety Aspects No significant effects. Summary and Critical Discussion AD .S «1 Cost per Million BTU The basic cost of heat energy from a diesel generator heat recovery system is estimated to be $3 to $5 per MMBTU based on a 20-year equipment life. Heat energy costs from oil fired heaters are estimated to be $20 to $30 per MMBTU in comparison at Alaska villages. Ad 2G wd Critical Discussion of Technology Waste heat recovery methods from diesel generators are a known technology today. It is an effective way to reduce oil consumption in a village with the expenditure of capital. The jacket heat recovery systems are extremely reliable and appropriate to village applications. But the exhaust type gas to liquid heat exchanger units have higher operation, maintenance and initial capital costs per BTU of heat recovery and are described as optional equipment in the report. A335 DIESEL GENERATOR ENERGY BALANCE Non-recoverable 20% Total Exhaust=35% / Recoverable Exhaust 15% 20% Non- recoverable y Exhaust on. | Work-30% Jacket Water Recoverable 30% EXHAUST WASTE HEAT ELECTRICITY 30% 35% 35% DIESEL GENERATOR- NO HEAT RECOVERY EXHAUST WASTE HEAT RECOVERY ELECTRICITY 15% 50% 35% DIESEL GENERATOR- WiTH HEAT RECOVERY ADDED Ba ria WANS ae A3.6 200°F| WASTE HEAT RECOVERY _ FROM A O/ESEL GENERATOR ~~ Fig. A3.2 A3.7 HEAT AVAILABLE WASTE MAX. % 100 80 60 40 20 AVAILABLE WASTE HEAT * TOTAL JACKET WATER AVAILABLE ! | ! ! ! ! \ ! ! * 20 40 60 80 % KW LOAD RATING (DERIVED FROM DATA IN THE CATERPILLAR CO. MANUAL) Big. A3..3 A3.8 100 NOT AVAILABLE AT EXHAUST HEAT EXCHANGER A4.0 HYDROELECTRIC POWER Ad.i General Description eT eel Process Man has used the energy in falling or moving water since the days of the Romans to perform work for his benefit. Modern man has improved on the method to recover the maximum energy from the water in a device called a turbine. The turbine takes many forms but basically uses the velocity of water to turn a shaft to drive an electric generator. A4.1.2 Availability Turbine generator equipment is available from a number of suppliers in the U.S., Canada, Europe and Japan. Medium to low head units in the range of 150 KW are available from James Leffel within 10 months. Barber Dumont of Ontario, Canada, quotes similar units in 3-8 months. A French company, estimates 10 to 11 months delivery. Medium head (300 meters), low flow (2 cfs) units in the range 37.5 to 50 KW are also available in the same delivery period. Performance Characteristics . A4.2.1 Energy Output A) Quality Electrical energy, either synchronous or induction AC generators are available. A4.1 ING PAG B) Quantity Turbine generator units are available in many types and sizes. Application is dependent upon usable stream flow and head available. Cc) Dynamics Output is seasonally dependent on stream flows which swell during spring runoff or rainy season and diminish during cold or dry weather. In some cases, all the electric power needs of a community mav be supplied for a period of time during the year when there is high maximum water flow, or only peak load power may be supplied for part of the day. Other power sources such as wind or diesel generation may be required to make up for the periods when water is not available or demand exceeds the capacity of the hydro system. D) Storage A reservoir can be utilized to level the output and to ic 4 oO ne peak demand. A reservoir may add considerable cost to the installation. Each installation will have to be considered separately to determine the economics of water storage. 2 Reliability A) Need for Backup Hydroelectric power generation is one of the most reliable methods of generating electric power. Life expectancy of this type of equipment has proven to be in the range of 25 to 35 years with minimal care and A4.2 maintenance. The backup is required during maintenance outages especially on small, single generator installations. Large multi-turbine installation would have the backup power installed. B) Storage Storage of water in a reservoir usually improves the availability of energy. More uniform seasonal output can be provided using a reservoir, however if the stream has more than enough capacity to meet the needs of a community, the unit could be adapted to "run of the stream" operation. Cc) Efficiency Turbine efficiencies vary with type, flow and load but usually range from 75-90%. Generator efficiencies are approximately 95%. Combined efficiencies range between 70-85% in the expected range of operation. A4.3 Costs A4.3.1 Capital Cost Capital cost for a small 140 KW hydraulic turbine generator operating under a head of 50 feet with a flow of 45 cubic feet per second (cfs) is approximately $85,000 for the turbine-generator, necessary gearing, governor and the electrical control panel. A representative 40 KW unit operating under a head of 300 feet and flow of 1.75 cfs per second would cost approximately $50,000 for the same equipment. Transportation from point of manufacture is not included. site development, materials and equipment required for installation will vary greatly with the site A4.3 location and conditions. Water impoundment and/or diversion, structures, penstocks, foundations and provisions for the discharge will also vary over a considerable range. A4.3,32 Assembly and Installation Assembly and installation including design and supervision is estimated at 50-60% of the total installation. This allocation would apply for units installed in the "Lower 48" with resulting installed cost between $175,000 and $215,000, respectively. Costs for installation in the remote areas of western Alaska are considerably higher. Small systems in remote Aleutian or Western Alaska site may cost between $600,000 and $1,000,000. These cost may be justified considering the high cost of diesel generated power in these areas. A4eSi Operation and Maintenance All equipment used in a hydro-electric installation is typically rugged, well designed equipment requiring minimal maintenance. It is designed for long service life. Operation and maintenance of this equipment would not require skills beyond those already employed to operate the diesel generator equipment presently installed. Alaska District Corps of Engineers has suggested operation, maintenance and replacement cost at $8,000.00 per year for the 150 KW unit. A4.3.4 Cost Cost per installed KW will range from $18,000 for the high flow, low head installation with a dam to $7,000 for a low flow, high head project with diversion only. These costs are approximate for western Alaska construction. A4.4 A4.4 Special Requirements and Impacts B44. 0 Siting The turbine would be located to maximize output from the water and head available taking into account length of penstock and storage available. The average village installation require a relatively small power house. Siting is not considered a problem provided the soil conditions are stable and not subject to flooding or erosion. The penstock may or may not be covered but winter weather conditions may require protection from freezing and snow loads. A4.4.2 The Resource Water is a renewable resource dependent upon the following characteristics: A. Drainage area B. Storage available by means of a reservoir or natural storage, e.g. groundwater and/or snowpack. cE Average rainfall in the area. na 5453 Environmental Impacts Environmental impacts are minimal in small streams with no fish habitat. Each location must be analyzed for its impact on fish and wildlife. The maior impact is where a reservoir would cccupy a large area of land. Recreational use could be a desirable result. A4.4.4 Construction and Operating Skills Normal civil and construction skills would be required. A small installation would be a package arrangement requiring A4.5 A4.5 minimum technical assembly skills. Operating skills would be similar to those required to operate the present engine-generator units. A4.4.5 Health Effects There are no particular aspects to this technology which would effect health and safety. Summary A4.5.1 Cost per Kilowatt Hour Cost are dependent upon so may variables that it is not possible to established a firm cost per KWH. The Alaska District Corps of Engineers has forecast a cost for 31¢ per KWH for 150 KW medium head installation. Ba. 5). Critical Discussion The process of converting the potential energy of water at hich elevation into electrical energy by use of a turbine generator is a proven process. The equipment involved is extremely reliable. In Western Alaska the period of maximum generating capacity does not always coincide with the period of maximum demand. Highwater flow, thus maximum output of a hydro installation is usually during spring runoff beginning in April, peaking in May and June and ending in July. The coldest temperatures (average -20°F) and maximum energy demand is between November and April when stream flows are diminished by freeze up of the water drainage system. Diesel generation is sufficiently flexible to allow maximum use of the available hydro however. A4.6 In the Aleutian stream drainage freeze up is not as signifi- cant as Western Alaska because of moderate winter temperatures. Stream flow is a function of precipitation. Continuous stream flow throughout the year makes hydro a viable technology in this area. A4.7 AS5S.0 W +37 ali D ENERGY CONVERSION SYSTEMS A5.1 General Description A5.1.1 Process Wind turbine-generator (WTG) systems are devices used to convert the kinetic energy of wind into shaft torque by means of a propeller and then to electrical energy by a generator. The propeller or wind turbine may also be used directly to do mechanical work such as pumping water. The application considered here is the generation of electrical power. A wind turbine or wind machine, as they are commonly called, is designed to extract energy from the wind. The wind turns the rotor or blades of a turbine by "pushing" against them or by lifting the blades aerodynamically. The energy that can be extracted by "pushing" (drag principle) is limited. Modern wind turbines rely on the "aerodynamic lift" which is achieved by the special shape of the blade (called an airfoil). This shape is similar to that of an airplane wing which produces a low pressure area above the wing and a high pressure area below the wing. The difference in pressure between the two sides of the blade allows it to move with great speed and efficiency. The top speed of the blade revolving around the hub will be greater than the speed of the wind. The relationship of the blade speed, measured at the tip, to the wind speed is called the tip speed ratio. The energy extracted from the wind by this system of airfoils is used to drive an electrical generator or alternator. Generators may be AC, either synchronous or induction, or DC, depending on the application. In addition, alternators are often used on smaller capacity wind machines. A5.1 Wind systems are comprised of four major components: A) the wind turbine, which provides either mechanical or electrical power, B) the support system or tower, C) the storage system (if used), which can include batteries, a connection to an electric utility power line, or to some other form of energy storage such as water or space heating, D) the electrical sub-components such as inverters, voltage regulators, control systems and switching devices. AS odie Current and Future Availability Wind machines have provided man with mechanical energy for centuries. Their use to generate electrical energy dates back to the late 1800's. Many improvements in turbine design and application have been made in the last few years. Wind machines are currently used to generate electricity in areas where there are no public utilities available. Interest in larger units suitable for incorporation into a utility grid has resulted in a number of units being installed and tested by private as well as government agencies. The Energy Systems Group of RockWell International is providing technical and management support for the DOE testing programs at Rocky Flats in Colorado. All of their testing is on small wind energy conversion system (WECS) under 100 KW. Both commercial and prototype models are AS (2 being tested, as well as various types of tower and guy assemblies. The Energy Systems Group is also investigating the impacts of SWECS on utility grids. There are a number of wind energy demonstration projects on WGT sizes of 2, 10 and 20 KW. Manufacturers who appear to be viable suppliers in the Alaska market are Enertech, Aeropower, Grumman and Jacobs. Demonstration projects are now going at Unalakleet, Nelson Lagoon, Sheldon Point and other sites but data on their reliability, and energy savings is inconclusive. A Grumman 18 KW machine was installed at Nelson Lagoon. After experiencing major problems the machine has been redesigned and has been operational since May 1981. Because of remoteness of the site and operational problems the unit has run only 30% of the time. Data is not available on the effectiveness of the wind generator in reducing all usage in the village. At Sheldon Point, which has no central generation, several 2 KW WECS have been installed on individual houses. Monitoring systems have not been installed to adequately demonstrate the output of these machines. Other manufacturers of larger WECS are WTG Energy Systems, Alcoa and Boeing. These large systems, greater than 100 KW are not suitable for small village application at this time. A5.3 A5.2 Performance Characteristics BS) 02. Energy Output A) Electrical Generation Wind turbine generators are manufactured in a number of configurations, using alternators, AC synchronous or induction generators, or DC generators. they are manufactured in many sizes ranging from a few watts to several megawatts. Refer to Section A9 of this Appendix for a discussion of the electrical characteristics of these configuration. B) Quantity The quantity of output power is a function of the area swept by the rotor and the velocity of the wind at the point of installation. Power available in the wind increases with the cube of the wind speed. Figure A5.1 demonstrates the relationship between the unit output (KW), size of rotor and the mean wind speed. Most units have a cut-in speed of approximately 8 MPH and a cut-out speed of approximately 40 MPH, however, maximum KW output occurs between a particular design speed (such as 25 mph) and cutout speed. Optimum utilization of wind turbines occurs in areas of persistant low velocity winds where the mean wind speed is approximately % times the design speed of the turbine. The total annual kilowatt hour output depends on the average annual wind for the area. Curves shown on Figure A5.2 demonstrate this relationship for some small machines. A5.4 Cc) Dynamics The output of a wind machine is dependent on mean wind velocity and is, therefore, affected daily as well as seasonally. Areas near a large body of water generally have afternoon or evening winds on a daily basis. Most areas are seasonally affected generally having higher velocities in winter and lower velocities in spring and summer. Wind speed is also affected by pressure changes, variations in landscape and attitude. Each proposed wind turbine site should be analyzed individually to determine its wind resource data. AD 2 aie) Reliability A) Need for "Backup" Because of the intermittent nature of the wind, a wind turbine will require 100% "backup" power. "Backup" power can. be obtained in several ways such as battery storage, hydroelectric reservoirs, or a utility tie. B) "Backup" Storage in the form of batteries or hydroelectric reservoirs would allow maximum utilization of the system and even out fluctuations of energy flow during the day as wind velocity varies. Connections to utility grids provide backup power when wind production is insufficient to meet power needs. AS.5 AS 3) Asanel fficiency Very little data is available on the efficiency of wind machines as related to captured wind energy versus available wind energy. Yeither available energy nor average wind speed is always a reliable measure of the potential performance of a wind machine for two reasons: 1) a turbine cannot produce additional power from wind speeds higher than its rated or design wind speed, and 2)) the distribution of wind velocity at various adjacent sites can differ appreciably. Studies have shown that captured energy as a percentage of available energy can range from 8% to 25%. Cost The total cost of a wind turbine installation includes costs for the site, turbine with generator, tower, storage system or utility tie (if used) and associated electrical equipment. ASnsn L Capital Cost The installed cost of a wind turbine system will vary greatly because of the many parameters peculiar to a given installation. Equipment cost of a wind turbine generator with a tower is approximately $2,000/KW for a large (greater than 100 KW machine) synchronous or induction machine and approximately $4,500/KW for smaller units complete with inverter and batteries. AS .3.2 Assembly and Installation Installation costs are dependent upon local site conditions and costs specific to the region. Soil conditions in some A5.6 areas of Alaska will make installation of wind machines Gi fet couule,. The unit will have to be positioned in a location and at an elevation to extract the maximum energy from the wind. Elevation of the turbine above the ground is one of the most important considerations. Cost of additional tower height is generally more than offset by additional energy output. A5.3.3 Operation and Maintenance Cperations and maintenance costs of a wind turbine are dependent upon the type of system installed. Wind systems using DC-to-AC power inversion may involve electrical controls and/or batteries for voltage regulation and system stability. These components may add high incremental operation and maintenance expense. For example, average battery life expectancy is 10-12 years and costs approximately $8/amp hour at 120 volts. Costs will also depend upon the complexity of the control involved in integrating the wind turbine-generator into the existing utility system. A5.3.4 Cost per Kilowatt Installed Installed costs for a 100 KW unit in 1982 is expected to be approximately $2,000/KW in the lower 48 states. Installed cost of smaller units at $4,500/KW should hold steady for the near future, as increased production efficiency is offset by inflation. AS.3.5 Economies of Scale In general, there is an economic advantage in installing the largest unit which will serve the needs of the installation/area. This advantage must be weighed against the impact of large wind system ties to small utility grids. A5.4 Special Requirements AS 345k Siting A wind turbine generator will require siting in an area known to have an average annual wind velocity of sufficient magnitude to justify costs of installation and operation. This velocity is usually 12 mph or greater, depending on the machine characteristics. A wind turbine must be located where it has access to the free flow of the wind from 360°. Its power potential is greatly enchanced by its height above the ground. The least expensive way to increase energy output from the wind is to increase tower height. A5.4.2 Resources Needed A) Renewable - An area which has a means wind velocity of 12 mph or greater is necessary to consider installation of a typical wind machine. B) Non-renewable - Not applicable. Wind turbines are designed to take the energy out of the wind when it is available and, as such, are unregulated sources of energy. To receive the maximum benefit from the wind system there must be a demand for this energy. To optimize this demand, the energy contributed by other sources must be regulatable. Diesel generation, hydro and steam power plants are examples of power supply systems which can be regulated. In theory, the maximum size of an unregulated wind system relative to the load of the utility should be equal to the A5.8 minimum instantaneous electrical demand on the system. However, in practice, the size is further affected by several factors. Design factors such as energy storage, excess energy dissipation, and projected load growth would tend to increase the maximum size. Electrical system factors such as frequency stability, wave form distortion (harmonies), voltage regulation, voltage flicker, and power factor generally tend to decrease the maximum size. The impact of any given parameter depends on both the type of wind system proposed and the makeup of the utility grid to which it is tied. BS 4.3 Construction and Operating Skills Normal skills associated with construction and operation of any other electrical generating plant. Where sophisticated electronic controls are involved, it will require this discipline. A5.4.4 Environmental Wind machines may have both visual and audio impacts associated with them. These effects must be weighed against the reduction of exhaust gases and importation of high cost fuel oil from outside the region. AS..4.9 Safety and Health No safety or health effects are anticipated from a wind machine. AS.9 AS5.5 Summary and Critical Discussion AS .6 ASS <d Cost per KWH Estimated cost per KWH range from $.10 to $.30/KWH depending on wind velocity and site conditions. DS ele Zhe Discussion Improvements are continually being made in the design and application of wind turbines. Rapidly escalating cost of fuel oil, at a rate far above the annual inflation rate, will make alternate energy sources more and more attractive. Presently wind turbines are not cost effective in areas of relatively low cost energy. In areas of western Alaska where electrical generation cost is near $.31/KWH and rising, a wind machine can be an attractive alternative. A wind machine in western Alaska, however, does not displace other forms of generation and, therefore, does not receive the benefits and considerations of a unit which can reduce the demand for high cost thermal generation. Its total economy is in fuel not burned. References Is Wind a Practical Source of Energy for You? DOE, TM-IP/80-3, Sept., 1980. ae Assessment of Wind Energy System as a Utility Framework. S.L. Mackis, J.L. Oplinger. Kc Wind Supplies Much of Cuttyhunk Islands Electric Power. W.R. Loustut, Electrical Consultant, Sept.-Oct., 1979. oP Oregon Wind Book, Oregon Department of Energy, 1978. A5.10 Performance Summary Sheets, Rocky Flats Wind Systems Program, 12/80. An Assessment of Power Quality Requirements for Small Vind Energy Conversion Systems. DOE, TM-IP/81-3, April, 1981. AS.11 maximum power (watts) 15,000 10.000 3020) 4,000 3,000 2009 TOO) Typical Wind Power Curves Pig. Adi. 1 A5.12 D=3D D=25 — Ty 1 D=20 7 | __ D= rotor D=15 diameter (feet) | | | | ft | {| Yi tt} | | LTA [| | titi | | | J D=10 Liz] TH | | { | | 1D=5 — | C1 ry il 5 10 15 20 25 30 wind speed (mph) ANNUAL ENERGY OUTPUT, kWH Annual Energy Output vs Mean Wind Speed TYPICAL ANNUAL ENERGY OUTPUT FOR SMALL WIND SYSTEMS Note: Assumes Rayleigh distribution of wind speed probability. Actual output may vary due to different characteristics of specific machines or sites. ROTOR DIAMETER 100,000 45 ft 90,000 40 ft 80,000 70,000 35 ft 60,000 50,000 30 ft 40,000 25) tt 30,000 20 ft 20,000 10,000 ee 8 10 12 14 16 18 20 MEAN WIND SPEED, MPH Fig. A5.2 A5.13 A6.0 GEOTHERMAL ENERGY A6.1 General Description The recovery of geothermal energy involves capturing heat available in the earth. Current technologies are directed at utilization of this captured heat for home or process heating or generating electrical power. A common example of geothermal energy are hot springs which in the U.S. are found mainly in the west, Hawaii and Alaska. There are several types of geothermal resources. Hydrothermal resources occur naturally as either vapor dominated or hot water dominated subsurface regime dependent on temperature and pressure circulation. The hydrothermal resource will be discussed herein. AG .do1 Thermodynamic Process There are two thermodynamic processes involved which depend on the temperature of the resource. For low temperature hydrothermal resources the heat may be used to heat homes, enhance agriculture development, or support industrial processes requiring low temperature heat sources. Excellent examples of this type of resource are located at Klamath Falls, Oregon and Boise, Idaho where there are a number of small and large district heating systems utilizing geothermal resources. The second thermal process involves a higher temperature hydrothermal resource where the water exists as steam or is flashed to steam to drive a turbine or is used to vaporize another fluid to drive a turbine to generate electrical power. The highest quality energy resource, steam, can be used directly to drive a steam turbine. The steam condensed in the turbine is then re-injected into the ground in the liquid phase for revaporization. A6.1 A6.2 It should also be noted that for lower quality temperature resources, the steam or hot water may also be used to evaporate an organic fluid to drive an Organic Rankine Cycle power generation system. A6.1.2 Current and Future Availability The practicality of geothermal energy recovery and utilization has been demonstrated at a number of locations throughout the world. The primary example of geothermal power generation is The Geyers in northern California which has an estimated installed capacity of 1,800 MW. Other power ceneration sites are located in Italy and in Iceland. District heating utilizing geothermal energy has been demonstrated in a number of locations including Klamath Falls, Oregon. Performance Characteristics AG a2 Energy Output Generally, geothermal energy output can be characterized by a wide range of physical conditions at the sources ranging from low temperature hot water sources at 150°F to high pressure steam up to 500°F. The quantity of heat available depends on specific site conditions which must be defined by exploratory drilling or other methods. These resources do not vary with the seasons, only long term use of resources will produce daily or annual fluctuations. AOn2mee Reliability Once these resources have been developed, the reliability can be designed and built into the system to eliminate the need for backup. The primary operational concern with use A6.2 A6.3 ef geothermal sources is that they may carry a large quantity of dissolved solids or gas. Solids can be Geposited on heat transfer surfaces or on turbines blades and eventually destroy the efficiency of the device. The resources must be analyzed and carefully cuantified to determine the design conditions required to minimize maintenance due to mineral depositions. Under more severe conditions backup equipment may he necessary to provide continued operation during cleaning operations. A primary advantage of gecthermal energy is that the storage medium is the earth and no additional storage is necessary to back up this resource. Ao 5263 Thermodynamic Efficiency Thermodynamic efficiency depends on the end use of the resource. Geothermal energy use for heating can be used at high efficiencies on the order of 90%. That used for the generation of electrical power is more typically on the order of 10-30% depending on the pressure and temperature conditions at the resource. Cost for Unit AG sSiaL Capital Cost A major capital cost is in drilling and developing of the resource. The associated cost elements are extremely variable and are dependent on the specific site conditions and location. Once the resource is defined the equipment necessary to transform the energy or convert from geothermal heat to power or space heat can be installed. Development of this resource for electrical power generation is usually more ccestly than for district or process heating. A6.3 A6.3.2 Assembly and Installations The major components of a geothermal energy development include casings for wells, piping, heat exchangers, power generation equipment and transmission facilities. The equipment and installation cost would be dependent on the size of the resource and how it is used. Estimates of these costs have never been prepared in sufficient detail for Alaska or Aleutian Island installation. 3.3 Operation and Maintenance Once a geothermal resource has been developed, the operation should be fairly conventional and straight forward. The major cost is maintaining the heat transfer surfaces and pipes depends on quality of the geothermal resource. Geothermal waters are known to contain chemicals that can attack and corrode conventional metals. This information is usually developed early in the exploratory period to determine the final cost of installed equipment and to support cost projections. A6.3.4 Cost per KW Installed Installed costs for this equipment are highly variable and are especially sensitive to site specific conditions. Ae 3/s5 Economies of Scale The economics of geothermal energy utilization will be in part dependent on the size of the load to be accommodated. The larger the demand for heat and electrical power the more efficient it will be. Development cost for small villages may not be economical because of the large investment in the A6.4 A6é. site developed of geothermal wells compared to the potential utilization of the resource once the wells are developed. Special Requirements and Impacts A6.4.1 Siting The siting of geothermal development will depend on its lecation and subsurface character. A number of studies have been performed to identify potential locations. However, only very few rudimentary studies have been conducted to date which are directed at defining the subsurface character of Alaska's geothermal resources. Some of Alaska's geothermal resources exist in national parks or forest lands which may require extensive permitting activities. A6.4.2 Resource Needs Not applicable. A6.4.3 Construction and Operating Employment Development of a geothermal resource will require application of the following skills: geology, engineering, environmental sciences and economics. Specific construction skills will involve civil, mechanical and electrical crafts complimented by reservoir development engineering. Further, operations labor will include piping and boiler operations along with electrical maintenance skills. A6.4.4 Environmental Residuals Environmental residuals from geothermal would be from the water or steam that is released to the atmosphere. Systems A6.5 645) would generally be designed to re-inject these residuals back into the reservoir to prevent mineral contamination of the surface waters. Some geothermal resources may contain gases which could escape to atmosphere during the process. These gases would have to be disposed of in an environmentally acceptable manner. A6.4.5 Health or Safety Aspects Health or safety hazards may occur during the development of the well. Sufficient precautions must be taken to prevent well blowout or loss of resource. The piping and auxiliary equipment that comes in contact with the geothermal resource must be designed to adequately handle the pressure and temperature that may exist in the system. The conscientious use cf design codes for the design of pressure piping systems is essential to the safe operation of the system. Summarv and Critical Discussion A6.5.1 Cost per MMBTU and per KWH At this point development of this technology in Alaska has not proceeded far enough to estimate these costs. AG 5 212 Critical Discussion of Technology The major impediment to the development of geothermal energy in Alaska is the high cost in locating and developing the resource in remote areas where the potential exists. Further, the resource does not necessarily exist where the population is located. The major areas of geothermal resource occur in the Aluetian Chain and the Alaskan Peninusla. Other areas have been identified in the north central portion of the State extending from the Canadian border through the Seward Peninsula. A6.6 A6.6 References aS Alaska: A Guide to Geothermal Development, Niel Basescu, et al., OIT Geo Heat Utilization Center. Dis Draft - Alaska Geothermal Implementation Plan, John W. Reeder, et al. for U.S. DOE Region X, 1992 Federal Bldg., 914 Second Ave., Seattle, WA 98174 A6.7 A7.0 STEAM POWER GFNERATION FROM COAL/WOOD/SOLID WASTE/PEAT -1 General Description A7.1.1 Thermodynamic and Engineering Process Coal, wood, peat and/or solid waste from a community could be burned in a boiler to generate steam at a high pressure. Stream would then be passed through a turbine which would drive a generator. When the steam passes through the turbine the only heat removed is that equivalent to the shaft energy (which includes generator and other mechanical losses from the surface of the machine). The remaining heat in the steam must be extracted to condense it back to water. The efficiency of the steam cycle depends on the initial temperature and pressure that can be developed in the steam and the pressure at which the steam is exhausted. The amount of shaft power that can be extracted from steam can range from as little as 5% in small, back pressure turbine to as high as 40% in a large, high pressure power generating plant. Electric power requirement in the villages range between 100 and 500 KW. Steam boiler equipment and turbine generators available in the commercial market limits the efficiency of the steam system to the low end of the efficiency range, i.e. about 6 to 10%. A7.1.2 Current and Future Availability Steam power has been used by man for several hundred years. Very early steam generators were low pressure units used to drive steam engines. As technology evolved, the steam generating plants became larger and more efficient. Emphasis was placed on large centralized power plants to gain economy of scale while small system technology did not receive the benefit of development. The technolcgy required A7.1 A7.2 for the villages goes back to the early days of steam power where the steam pressures and the overall system efficiency were low. Steam power can be justified at these low efficiencies if there is locally available fuel at proportionately lower cost than oil which must be imported to the region. A facility at a village sized for 200 KW would consist of a boiler capable of generating 6,500 pph of 150 psig saturated steam driving single stage turbine-generator. An air cooled condenser operating at approximately 15 inches of mercury vacuum would remove the residual heat from the steam. This installation would require approximately 32 pounds of steam per KWH. A water cooled condenser could be substituted for air cooled where sufficient water was available. The plant would require 1090 pounds per hour of 10,000 BTU per pound coal or 1250 pounds of wood per hour. The overall plant efficiency would be approximately 6.3%. An alternative to this arrangement, which would improve the recovery of the heat energy from the coal, would be to condense the steam while heating a circulating fluid such as glycol that would provide heat for buildings and water heating. The steam rate would be 46 pounds per KWH but much of the residual heat would be used for heating purposes. See Figure A7.1. Performance Characteristics BT eee Energy Output A) Quality The output of this system would be electrical energy and heat at approximately 200°F available for district heating use. A7.2 B) Quantity The quantity of energy available will depend on the amount and type of fuel available in the area. Cc) Dynamics Fuel can be made available to meet any daily seasonal or annual energy demand. A7.2.2 A) B) A7.2.3 Reliability Coal-fired steam generators would require a yearly maintenance period of 1 to 2 weeks. During that time backup generation may be required. There are a number of machines associated with power generation, including the turbine, pumps, fans and other auxiliary motors that will effect the overall system reliability. Sufficient fuel storage is required for the longest estimated time between fuel deliveries for any circumstances. If the fuel is locally available, the storage requirements can be minimized. Thermodynamic Efficiency Thermal efficiency in the system in this range will vary from 5-83, The overall efficiency of the system can be improved by utilizing the exhaust heat for district heating. A7.3 A7.3 Cest for Typical Unit Af aen Capital Capital requirements for a 250 KW installation follows: A) B) Cc) D) A 32 nr B) Cc) D) F) G) H) I) Ay ~3.3 Boiler and Auxiliaries Turbine Generator Condenser Electrical Switchgear Assembly and Installation Mobilization Foundation and Site Prep Fuel Storage and Handling Equipment Boiler Building Piping Installation of Boiler and Auxiliary Equipment Transmission Line (approximately) TOTAL Cost for Material & Labor Project Management (5%) Engineering (8%) Contingencies (20%) TOTAL Cost for Installation Operation and Maintenance Operation and maintenance costs included fuel, cost of maintenance. eSselnat ed at $4 per millicn BTU input. area as $130,000 45,000 20,000 10,000 $130,000 150,000 45,000 25,000 50,000 30,000 $635,000 32,000 51,000 127,000 $845,000 labor and Fuel costs delivered to the boiler are Assuming the plant operates at an average load factor of 50% and produces A7.4 876,000 KWH the annual operating cost are $142,000 labor costs are $40,000. Other maintenance costs are estimated to be $10,000 per year. A7.3.4 Cost per KWH Installed power cost is approximately $3,500 per KW. A7.4 Economy of Scale Economy cf scale can be gained by improved thermodynamic efficiency as well as lower cost per KW installed. It. is possible that some economy can be obtained if there is another nearby village to which energy can be transmitted. A7.5 Special Reguirements and Impacts A7.5.1 Siting The most important factor in siting a steam plant is the available local resource of coal, wood or peat and the ease of getting the fuel to the site. The site selected would have to take into consideration the prevailing wind and the effect of the stack gases on the village. A7.5.2 Resource Needs A) A facility like this requires locally available sources of wood or peat. If these resources are available then the village solid waste combustible contents could also be burned for additional heat value. A7.5 B) Non Renewable Resources Coal is the most likely non-renewable resource that could be fired in an installation like this. Depending on cost, it could be possible to consider coal either shipped in or locally available, for power generation. A7.5.3 Construction and Operating Employment by Skills A steam generation facility requires skills to construct, a substantial foundation, such as a pile supported steel structure, pipe fitters, welders, and persons experienced in the construction industry. Operating skills require a knowledge of steam power generation and control as well as knowledge of electrical power generation and distribution. A7.5.4 Environmental Residuals All fuels would create particulate emission as well as the possibility of emission of sulfur dioxide and NOX. The solid residual ash, can readily be landfilled. BT .D)65, Health or Safety Aspects A steam system would have to be comply with the latest safety codes and all the safety systems would have to be installed and maintained to prevent accidents. This method of generating power will require education of local manpower to operate steam power system. There would be possible increased emissions of NOX and sulfur dioxide which are not known to have related health effects with proper installation. A7.6 A7.6 Summary and Critical Discussion AT «66 Eneray Costs With energy costs based on fuel costs at $4 per MMBTU, an installation of this type will yield a cost/KWH of approximately 35.7¢. The resulting cost of electricity would be $105 per MMBTU of electrical energy consumption. AT 8.2 Discussion of Technology Steam-fired systems may be feasible provided there is a low cost source of fuel available in the area. Steam generation technology has been known and understood for many years. There are many moving parts within the system that require regular maintenance. The system design would have to incorporate sufficient redundancy to provide the reliability required in remote sites with a backup system to provide heat in the event of a breakdown to prevent freeze-up of water in the system. This technology has the advantage cf being able to incinerate local solid waste that comes into the village and recover energy from that source. The amount of energy in the solid waste, however, is low ccmpared to the amount of heat required to generate electric power from a small steam turbine. A7.7 150 PSIG SAT. TURBINE GENERATOR 464/KWh BOILER 10 PSIG DEAERATOR/HEATER Lo] J tf VILLAGE DISTRICT HEAT SYSTEM Pig. A7.1 A7.8 A8.0 GASIFICATICN OF WOOD, PEAT OR COAL A&.1 General Description Coal, wood or peat can be converted into a gas suitable for running diesel engines. The cost of these fuels if locally available will probably inflate at a lower rate than oil which could make this technology economically feasible for western Alaskan villages. A8.1.1 Thermodynamic & Engineering Processes Coal may be converted into either pipeline quality gas (approximately 1000 BTU/scf) or a low BTU quality gas depending on the complexity of the process. Low BTU gas (120-160 BTU/scf) can be produced with much lower capital investment and is considered here. The combustion/ gasification process proceeds in four steps: 1) Oxidation: Cr On— co 2 Hy + 1/2 0. H,0 + Heat 2) Gasification: H,0 Ey Heat + C + ( ) — co + ( ) co. CO 3) Hydrogasification: Cer 2H, CH, + Heat 4) Devolatalization: Coal + Heat —»* C + CH, + HC A8.1 This process was common prior to the development of natural gas transmission lines. Gasification of wood and peat has been accomplished successfully in Europe, and the technology is presently developing in North America. Peat and wood have very similar chemical make up, i.e., carbon content 50-55%, hydrogen 4-5%, and oxygen 30-40%. A significant difference between peat and wood is that the peat contains significantly more ash (5-15%) compared to wood (2%). There are a number of different types of gasifiers available in the various states of development. The typical unit converting wet wood in air, produces a mixture of gas, condensible tars and of 150 to 200 BTU/scf. Uses for the tars and char would have to be established in the village. Another type of gasifier utilizes a catalyst and is capable of converting 100% of the wood fiber and lighin to a gas buy requires a dry fuels, with approximately 20% moisture content. The resulting gas has a heat content of 300 to 350 BTU per cubic feet. A8.1.2 Current & Future Availability Development of small wood gasifiers has increased dramatically in the last 5 years. The development of modern gasifying equipment in the U.S. therefore is in the early stages and the most efficient, cost effective design has not been established. A French manufacturer produces the Duvant System capable of 100% conversion of material. A US. company, Pyrenco, is the development stages of a similar gasifier available primarily in sizes required in the villages. A8.2 A8 .2 Performance Characteristics ASis2.. 1 Enerayv Output A) Quality The output is in the form of a low BTU gas capable of being stored and/or piped directly to the gas consumer. Energy content between 150 and 350 BTU per cubic feet can be achieved depending on the process. B) Quantity Systems are available to generate the quantity of gas to operate diesel generators in the villages provided or to the size of 100 to 500 KW. GC) Dynamics Not applicable. AS. 22 Reliability The reliability of these systems is not developed at this time. Sufficient gas storage must be provided in the event of an interruption in the operation of a gasifier system. the backup could be in the form of diesel fuel. A&.2.3 Thermo dynamic Efficiency The energy conversion efficiency can be as high as 80% in wood or peat catalytic gasifier. The thermodynamic efficiency of a diesel engine would be approximately 30%. The resulting overall efficiency of 24% is theoretically achievable. Additional efficiency improvement can be A8 .3 A8.3 A8.4 achieved with a waste heat capture system from the diesel engine water jacket and exhaust gas. Cost for Typical Unit Installed Sie 3s Capita A gasifier to furnish gas to a 200 KW generator would cost approximately $250,000. A8.3.2 Assembly & Installation Not available. A8.3.3 Operation and Maintenance Not available. A8.3.4 Cost per KVJH Cost for processing renewable resources into gas is in the range of $4-5 per million BTU for a system capable of processing 3-4 tons per hour of feed stock. The cost of the feed stock must be added to the above. ASS > Economy of Scale Not applicable. Special Requirements and Impacts AG 403 Siting A gasifying process would be sited in an industrial zone that would provide for ease of bringing in the feed stock A8.4 A8.5 and be in the close proximity to the power generation facility where the gas would be consumed. A8.4.2 Resource Needs A) A locally available resource of wood, peat or solid waste could be used in the gasifier at the time. B) Coal if locally available - delivery cost and complexity of a coal gasifier would be the determining factor to determine if this process could be economically feasible. A8.4.3 Construction & Operating Plant by Skills Not available. A8.4.4 Environmental Residuals Primary residuals would be ash and combustion gases. A8i<4.5 Health and Safety Aspects Not available. Summary & Critical Discussion BSS oa Cost The current cost per MMBTU for the gasification process could be in the order of magnitude of oil depending on the availability of a resource for gasification. Oil presently ccsts $11-15 per MMBTU's in western Alaskan villages. If lower cost can be achieved through gasification it could greatly offset the use of oil in generating electric power. A8.5 A8.6 A8.5.2 Critical Discussion of the Technology Gasification of wood and peat is in a developmental stage in the U.S. and may be available from European suppliers. Further evaluation of gasification is required to determine whether the cost of a gasifier capable of 100% conversion of the feed stock would be competitive with the oil and the western Alaska environment. References 1. Synthetic Fuels from Peat Gasification by D.V. Punwani and J.M. Kopstein. 20 Gas Coal/DOE/FE/007. a Gasification of Coal and Wood by Lews Eckert III and Stanley Kapser, TAPPI, August 1979. A8.6 A9.0 SYNCHRONOUS, INDUCTION OR DC GENERATICN SYSTEMS A9.1 General Description AS. 11 Engineering Process Mechanical work from an unregulated source of energy, such as steam, water or wind is converted into electric energy by an electric generator. Typical large power systems use a synchronous generater which delivers alternating current (AC) at a closely regulated frequency, typically 60 Hz plus or minus a small tolerance. In the United States all large utility systems generate power with synchronous generators as do most small systems. However, additional alternatives are available for generating electrical power especially in small systems. These alternatives include induction generators, alternators, and DC generators. The AC induction generator is identical to an induction motor except it is driven at a speed slightly above the synchronous speed. The electrical output is generated from the slip, i.e., the difference between the synchronous frequency and the rotor frequency. The power output of an induction generator increases as the slip increases. An induction generator requires a magnetizing current which must be supplied from an external system such as a utility. An induction generator, therefore, is not suitable for isolated operation. Its application is limited to use in conjunction with an existing utility or synchronous generator. To avoid voltage and frequency regulation problems the size of the induction generator should not exceed 30 to 40% of the capacity of the main generator(s) currently operating. Where inrush currents are large enough to cause voltage flicker, the induction generator should be limited to 20% of utility capacity. AQ.1 Fer small systems it is possible to generate DC power with an alternator which has variable voltage and frequency output and convert that energy into constant frequency AC power hy means of a DC to AC inverter. The choice of inverter depends on whether the system will be tied to a utility grid. If a utility tie is proposed, the DC-to-AC power conversion would be made with a synchronous inverter. A synchronous inverter is a solid state device which regulates the voltage and frequency output of the alternator. These systems are available in sizes up to about 10 KW, with certain models upgradable to about 25 KW. If a "stand alone" system is proposed, one of two types of inverter is generally chosen: solid state or rotary. A solid state inverter converts the DC power to AC power with no moving parts and is more efficient and more costly than a rotary inverter. A rotary inverter uses the DC output from the alternator to run a DC motor, which in turn runs an AC generator to produce AC power. Rotary inverters are somewhat more reliable than solid state inverters. These systems are available in sizes up to about 8-10 KW. "Stand alone" systems generally will incorporate some method of energy storage such as batteries. Another possible choice for interconnecting a small energy source with a utility is a DC generator and static inverter. DC generators are typically more costly than synchronous generators, induction generators, or alternators. Similarly, the static inverter, a solid state device which converts the DC output to a regulated AC output, tends to be more costly than a synchronous inverter. A9.2 A9..2 Since the DC generator does not require a reference voitage or frequency from the utility, this system inherently provides "stand alone" capability. The most common form of energy storage is batteries, which can add considerably to the cost of the system. While the overall cost of the DC generator system can be nearly double the cost of a similar capacity AC generator or alternator system, the DC system offers the most versatile and independent method for using or distribution the power. A9.1.2 Current and Future Availability Each form of this electrical conversion method is available today. The synchronous generators, while available over the entire range of sizes that could be conceived for village power generation, require fairly sophisticated and costly controls which currently limits their application to larger kW sizes. Induction generators are available in sizes up to very large motor sizes; however, their economic range is between 10 and 500 KW. Combined alternator and DC-to-AC converter systems are available in sizes up to about 25 KW. The use of a synchronous inverter allows the flexibility of operating a small system in parallel with a utility AC systems, thus enabling a utility to offset its power consumption from outside sources while still having the flexibility and reliability of the larger system when its own generator output is not sufficient. DC generators and static inverters are also available in the small size range. Performance Characteristics AI .2.1 Energy Output For all systems mentioned above, the output is a form of electrical power, either AC or DC. Its quality, quantity AQ .3 Ad .3 and Gynamics are a function of the prime mover, the source of energy, and type of inverter used. AS.2.2 Reliability The synchronous generator has the highest reliability because it can provide regulated AC power over a wide range of operation. The induction system can only be operated in conjunction with a large synchronous-controlled system. It cannot operate on its own. The alternator/inverter system can cperate either independently or in conjunction with a large synchronous system. The DC generator/inverter system is the third "stand alone" option. AQn265 Efficiency Most AC or DC generators, when operating within their design capabilities, are approximately equal in efficiency rating. The alternator/inverter system or DC generator/inverter system tied to a utility grid, would have additional inefficiencies due to the losses in the AC-to-DC inverters. Cost for Typical Unit Installed A9<3.1 Capital Costs The synchronous generator would have a higher cost for small systems than induction generators but would be more cost effective above the 500 KW size depending on the type of prime mover. The induction generator would provide the lowest cost for a small power system provided that there is a large generating network that can use its output, regulate the frequency and provide field magnetizing current. Small capacity alternator/inverter systems can be obtained for a cost comparable to small induction generator systems. A DC AQ.4 A9.4 generator and static inverter has a higher cost than either the synchronous generator, induction generator, or alternator/inverter systems. BO). 2, Assembly and Installation Costs for assembly and installation would be approximately the same for the four types of generators. In some instances the form of generation is dictated by the prime mover. AQ 303 Operation Maintenance The operation and maintenance of these systems would be approximately the same. Induction generators and alternator/inverter systems, due to their reactive requirements generally can provide only 20-40% of the total power of a system without causing problems with the voltage or frequency regulation. Additional equipment, such as capacitor installations, may be required to obtain satisfactory operation in the percentage range. aS.324 Cost per KW Installed Data not available. Ag.95% Economics of Scale Eccnomics of scale are as stated in previous sections. Special Requirements and Impacts BO Sad « Siting Not Applicable AQ.5 A9.5 n A9.4.2 Resources Needed Not Applicable A9.4.3 Construction and Operating Employment by Skills All methods of generation require similar construction and operating employment skills. A9.4.4 Environmental Residuals Not Applicable AS.4.5 Health and Safety Aspects Not Applicable Summary and Critical Discussions Ao. 5nd Cost Per MHBTU's or Per KW Hour Data not available. BG c5ia2 Critical Discussion of Technology For large systems synchronous generators appear to provide the flexibility required for operation cver a wide range of power output while providing regulated voltage and frequency. The cost factor for small systems is really not critical where the frequency and voltage regulation or a "stand alone" capability is a requirement. Induction generators can economically be added to large power systems where their small input into the systems does not significantly affect the overall frequency or voltage AQ .6 A9.6 reculation of the larger system. Induction generators should not contribute more than other alternatives generators. An alternator and synchronous inverter can be used on small wind systems which operate in parallel with the local utility. When the utility is down, the alternator/synchronous inverter system is also down. This combination cannot operate on a "Stand alone" basis without additional equipment. As with the induction generator, the alternator/inverter system offers the opportunity for generation of approximately 20-40% of power needs on a small diesel generation system. Alternator/inverter systems are more often used for wind generation than for other prime movers. The system that provides the greatest flexibility for power generation from an unregulated source of energy is the DC generator with a battery storage system and static inverter. This system can operate in parallel with a small utility or on a “stand alone" basis. The battery provides storage for excess energy from the generator, makes up energy deficits and also provides a reference voltage for the inverter. The disadvantages with this system are high cost, lower reliability and lower efficiency than obtained from other systems. Three phase power from this system is also very costly. References "Induction Motor Provides Co-generation When Used as a Generator", by Nathan Ponnel, Electrical Consultant, January, 198Al1. A9.7 "Recover Energy with Induction Generators", R. L. Nailen, Hydro Carbon Processing, July, 1978. “Turbine-generators, Induction vs. Synchronous", M. N. Halberg, and W. B. Wilson, Pub. Industrial Engineering News, July-August, 1954. "Assessment of Potential Participation of Wind Turbine Generators in Alaskan Utilities", by Alaska Power Authority, January, 1982 Status Update - Draft AQ.8 Al10.0 ELECTRICAL GENERATION MANAGEMENT ALO) 21. General Description ALO. do Process Description Electrical generation management is a process whereby the electrical load on a utility is met by operation of the most efficient generator(s). This can be done in several wavs. Typically, historical data is analyzed to determine the load profile during the day and those generating units are cperated that will best meet the load with some predetermined reserve capacity. As the load changes during the day an additional generator(s) is switched on or off the line to match the requirement. Planning is done based cn the expected hours of peak demand. For example, in a small village with one generator operating it may be possible to operate a smaller generator at night and a larger generator during the day to meet the larger loads of day time activities. Switching can be done manually, by a combination manual/automatic scheme or fully automatically with a transfer switch and program- mable legic process controller. ALO.L az Current and Future Availability Generation management is currently practiced by most large utilities. System sophistication ranges from utilizing automatic equipment for starting up remote, un-manned installations to systems as simple as manually bringing a generator on line in parallel with other generators. A10.1 Al on") Performance Characteristics ALON 2 a Energy Output These systems do net put out energy but provide for operating generators in an efficient range which results in reduction of fuel used for generating electrical power. The automated systems yield the added benefit of lessening the need for human intervention into the operation of a power generation system. A) Quality These systems allow generators to operate in their most efficient range thereby lowering fuel consumption and increasing the life of the equipment by operating it in the most favorable regime. B) Quantity The efficiency of most rotary machinery drops significantly below 50% of output. The generation management system would be used to shut down a larger machine and bring on a smaller one as the load drops in the village and reverse the operation as the load increase. Cc) Dynamics Generation management systems are designed to follow the dynamics of the power demand of a village. Ali0 eae Efficiency These systems, if well maintained will increase the operating efficiency of the diesel generators and increase Al0.2 their usable life. The operation and maintenance of the controls will require personnel who are fully aware of the utilization of the equipment. It would require that anyone in the village who will operate the system be well-schooled and paid adequately for their knowledge. Al0.2 Performance Characteristics Al10.2.1 Energy Output These systems do not put out energy but provide for operating equipment in a more efficient range to convert a fuel in generating electrical power. The benefit of these systems is to eliminate the need for human intervention in the operation of a power generation system. A) Quality These systems allow power generator to operate in their most efficient range, lower fuel consumption and longer time between maintenance as required. B) Quantity Most rotary machinery efficiency drops significantly below 50% of output. A generation management system would be used to shut down a larger engine or bring on a smaller engine as the load changes in the village. Cc) Dynamics Load management systems are designed to follow the dynamics of the power demand of a village. A10.3 Al0.2.2 Efficiency These systems if well maintained will increase the cperating efficiency of the diesel generating plants. It would require trained personnel to maintain and operate them. It requires that anyone in the village who operates system be paid adequately for their knowledge. 3 Cost for Per Unit Al10.3.1 Capital Cost The equipment cost for a generation management system can range from $2,000 for a manual synchronizing system to $15,000 and up for a fully automatic programmable logic controller. The cost is a function of the utility size and the real benefit to be derived from installing such a system. Cost of equipment rises as the complexity of the system increases. Al10.3.2 Assembly and Installation These systems are factory assembled and wired in the field with equipment to be controlled. For automated systems, there is a requirement for transducers (measuring devices) to provide continuous status information to the controller which decides the equipment to operate. These devices (transducers) must be included in the generator package or the controller package. Al0.333 Operation and Maintenance Once these systems are installed and operating no attention is required except to check that they are functioning satisfactorily. Maintenance is required on an as needed basis, that is, if the equipment fails to perform some A10.4 function there must be someone available who can determine the cause and the necessary corrective action to be taken. For sophisticated applications, this requires a skilled person with experience in process controls as well as electronics. Al10.3.4 Cost per KW Installed Not applicable. ALO. 25 Economies of Scale The same equipment would be required to control a 600 KW as a 100 KW system; therefore, the economics are more favorable with larger systems. The economic limit must be determined based on the expected savings from reduce fuel consumption measured against the cost of installation. Al0.4 Special Requirements and Impacts Not applicable to this technology. AUOS Summary and Critical Discussion Most small village power generation systems consist of two full capacity generators and a third small generator for summer time or off peak operation. Typically one generator, which is sized to carry the peak damend, is operated. There is generally no equipment for synchronizing a second generator, to meet a short term peak. To change over from one generator to another requires the second unit be started and the load transferred from the running unit to the new unit. During this switchover there is a interruption of power to the village and possible voltage surges that might Al10.5 affect equipment in the village. It also requires that a operator be available to make the switchover which requires a 5 to 30 minute time period. It would be possible to provide automatic switchover to reduce the cost of an operator. The typical electrical power consumption in a village finds the peak demands at the morning and during the evening meal hour. Thereafter the load subsides gradually until 9 or 10 pm when the load might he 20-25% of the day time load. If the same generator operates night and day it will have a poor fuel consumption curve as well as increasing generator and engine maintenance. Generation management is worth consideration in small villages. There could be significant benefits accruing from installation of a generation management system. It would increase the level of knowledge of generator operators in the village. It will reduce operation maintenance cost and fuel costs. The main draw back to its usage is that if the generation management equipment fails to function and prevents a generator from operating there must be somecne knowledgeable enough to promptly determine the cause of the malfunction, and start the generator in manual mode while the equipment is being repaired. A10.6 ELECTRIC POWER TRANSMISSION - SINGLE WIRE GROUND RETURN General Description All.1.1 Engineering Processes Alternating current (AC) power is typically transmitted over long distances using two wires to assure a low voltage drop from one end of the system to the other. Single wire ground return (SWGR) is a method which eliminates one of the wires by using the ground as a return path to complete the electrical transmission circuit. Electrical contact between the transmission system and the ground is accomplished by the use of several ground rods (3/4 or 1" diameter copper rods 10 to 20 feet long) at each end of the transmission line. The number of rods required at each end depends on the amount of power to be transmitted, the type of soil in which the rods are installed, and the allowable resistance between the rods and the ground. The total ground and single wire resistance should not be greater than the resistance of a two wire system. Ba ie2 Availability Zz Ground return transmission systems have been considered since the use of electric power began, but have never become widely used in the United States because of inherent problems with the system voltage level control. SWGR systems may be considered for use in remote areas where some economy of scale in the generating system can be achieved by connecting several small villages together with a transmission system. Provided that the transmission system costs are sufficiently low, the single wire system may offer some economic advantages to achieve this goal. The structures used should offer a reduction in wire length and All.1 line hardware. These simpler line support structures would be erected with a minimum of heavy equipment which would reduce the cost of construction in the bush. The hardware and the technology for accomplishing this type of transmission are presently available. The successful construction and operation of the SWGR transmission line between Bethel and Napakiak has proven the technical feasibility of the SWGR concept. For nearly two vears, this SWGR line has transmitted single phase power at 14.4 kv for a distance of approximately 18 miles. Three phase power is achieved in Napakiak with rotary converter (a combination of three phase motor with tapped windings and adjustable capacitors) located at the load side of the transmission system. vip eer, Performance Characteristics AU iol Energy Output There is no energy output from a SWGR system. Its qualification for consideration as a village technology is the ability to transmit a high quality type of energy from an efficient, large generating source to a small user. Bde ehy2 Reliability This method of transmission depends upon the integrity of the contact between the ground and the ground rod or mat installed at each of the terminals and a low resistance path in the ground between terminals. If the ground contact resistance becomes too great or is not dependable, voltage control problems may be experienced. Equipment must be installed in the system to detect changes of the ground resistance to shut down the transmission power if the All1.2 resistance exceeds a level which would cause an excessive voltage drop in the system. In addition, the reliability of this methcd of transmission is dependent on the structural strength of the overhead conductor and periodic guying since none of the structures are embedded in the earth. Therefore, if the line breaks, the structures will topple in both directions until reaching supported (guyed) structures. All .253) Efficiency Efficiency of a transmission line is a function of the energy losses due to the total resistance of the line. In addition efficiency is also measured by the ability to Maintain an adequate voltage profile when supplying loads. A typical transmission system is designed for a voltage drop of 5% to 8% of the rated voltage at the estimated average power transmission load. Al1.3 Cost To evaluate this technology, cost for a SWGR system should be compared with a multiple wire system. The following table is an approximate comparison of relative costs for the two systems. Ale Capital Cost 16 19 Cost Element Multiple Wire SWGR Power Pole Al1.0 Al.0 Wire, Insulators, Hardware Al.0 0.5 Grounding 0.8 Al.0 Subtotal 2.8 ee R116 342 Installation Power Pole Al.0 0.6 Wire, Insulators, Hardware Pole 0 0.5 Grounding 0.8 Al.0 Subtotal 2.8 A2Z.1) TOTAL 5 ALL .3 Aliases Operation and Maintenance It is expected that the operation and maintenance cost for the SWGR line would be approximately the same as those for a multiple wire system under normal operation. The additional costs to assure that the ground resistance of the SWGR line is within tolerance at all times would be offset by the costs borne to inspect the structural integrity and support strength of the conventional line. It should be noted that if severe winds and/or ice loading cause failure of the conductor, insulator(s) or structure(s), the operation expense of the SWGR line would be greater than for the multiple wire system since more structures would generally be involved per failure. Al1.3.4 Cost per KW Installed This cost is not currently available. ALiLedad Economy of Scale These systems are limited to single phase systems capable of transmitting small blocks of power to small villages. No economy of scale would be expected. Al1.4 Special Requirements and Impacts Bai 4ie Siting The same general requirements apply for SWGR as well as multiple wire transmission systems. However, because of the SWGR structures are not imbedded in the earth, their use in boggy areas or on tundra may be facilitated. Al1l.4 ANA. 4.12 Resource Needs Not applicable. Al1.4.3 Construction and Operating Employment by Skills The same skills are required for single wire ground return as for multiple wire systems. Al1.4.4 Environmental Residuals The same as multiple wire systems. Ba 455) Health and Safety Aspects The 1978 edition of the National Electric Code includes a prohibition against using ground return systems. Prior to that time there was no prohibition against these systems. A waiver of that particular requirement of the code is required to enable this technology to be used in the bush. Al1.5 Summary and Critical Discussion ALL. Sic Cost per KWH The relative cost per KWH for single village generation versus delivery of electrical energy to a village from a centralized power plant over a 10 mile long SWGR line is as shown: Village Plants - Al.00 SWGR - 0.67 Maximum economic distance for construction of a SWGR line to a village with a peak load of 100 KW is estimated at approximately 30 miles. A1L.5 Auda Sei2 Critical Discussion The use of this technology requires that the ground return maintain low resistance daily, seasonally, and annually. The SWGR system is not feasible for a distribution network where the system is tapped to deliver power at intermediate points unless suitable ground conditions can be found at the intermediate tapped point. Experience with this system in western Alaska has been developed with a demonstration line in operation between Bethel and Napakiak. Additional operation of the line should prove the reliability of the line design, enhance potential user confidence and encourage additional construction. Materials used in the construction of the line are, for the most part, standardized distribution and transmission line hardware. These materials are generally available from manufacturers within a reasonable time period. The success of the Bethel-Napakiak line has resulted in the planned use of two additicnal SWGR systems. The first line from Kobuk to Shugnak is currently under construction. Rights-of-way are presently being obtained for the second line, from Bethel to Oscar¥ille. The cost savings of a single wire system suspended on a conventional pole would not provide significant cost savings, i.e. savings of the cost of wire, insulators, hardware and labor of stringing that particular wire. The major cost would be the installation of the poles which would require heavy equipment. Al1.6 A11.6 In conjunction with the SWGR system, a new pcle design for use primarily in lew population density areas is being tested which could substantially reduce the total trans- mission line installation costs in remote location. The pole design being used in the present demonstration programs is an A-frame structure which floats on the surface of the tundra. The in-line or tangent towers are supported by the cable tension. Dead-end structures are installed periodi- cally to insure the stability of the system. All structures at corners are guyed utilizing plate anchors which are Grilled into the ground with man-portable drilling systems. This technology may be feasible where some economy can be gained by tying several villages together with a single, more efficient and more reliable generation system. References Le Design Charts for Determining Optimum Ground Rod Dimensions by J. Zaborszky and Joseph Rittenhouse, IEEE Transaction, August 1953. 2s A repert on the pregress and potential of SWGR systems should be available in early 1982 from the Alaska Division of Energy and Power. Aika? PROPERTY OF: Alaska Power Authority 334 W. 5th Ave. Anchorage, Alaska 99501 —