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HomeMy WebLinkAboutKingcove Oldharbor Hydro 2 of 13 1982Volume A FINAL SUMMARY REPORT Feasibility Studies for KING COVE HYDROELECTRIC PROJECT OLD HARBOR HYDROELECTRIC PROJECT LARSEN BAY HYDROELECTRIC PROJECT Reconnaissance Study for TOGIAK HYDROELECTRIC PROJECT Submitted by DOWL ENGINEERS ANCHORAGE, ALASKA In Association with TUDOR ENGINEERING COMPANY SAN FRANCISCO, CALIFORNIA DRYDEN & LARUE ANCHORAGE, ALASKA AUGUST 1982 ALASKA POWER AUTHORITY SUMMARY VOLUME CONTENTS Section Page FOREWORD I. INTRODUCTION I-1 II. KING COVE SUMMARY II-1 III. OLD HARBOR SUMMARY III-1 IV. LARSEN BAY SUMMARY IV-1 V. TOGIAK SUMMARY V-1 NBI-432-9526-SC i FOREWORD This volume, Volume A, is a summary report incorporating the findings, conclusions, and recommendations of the feasibil- ity studies for King Cove (Volume B), Old Harbor (Volume C), and Larsen Bay (Volume D) and the reconnaissance study for Togiak (Volume E). Volumes B through E are comprehensive individual project reports that present the findings and recom- mendations of studies to assess the economic, technical, environmental, and social feasibilities of hydroelectric projects for these four villages. Each of the volumes for the individual project reports consists of 12 sections and six appendices. The first section of each report is a concise summary of all activities conducted for the particular project. Following a brief introduction, Section I, these summaries from each volume are reproduced here as Sections II, III, IV and V and some similarity in format and narrataive will be noted. Selected photographs, figures and drawings have also been included with each summary section as appropriate. NBI-432-9526-SF ii TOGIA KING COV Ci 0 oQ oD LARSEN BAY LOCATION MAP FIGURE 1-1 SECTION I INTRODUCTION A. GENERAL This summary report presents the overall results of studies conducted to appraise proposed hydroelectric projects at King Cove, Larsen Bay, Old Harbor and Togiak. With the exception of Togiak, all studies were at the feasibility level and included the optimal sizing of all project features. The studies for Togiak were at a reconnaissance level since the prior studies were not as extensive and since the proposed project involves a small dam and is more complex. The studies were authorized by the Alaska Power Authority as a result of numerous prior studies of energy alternatives that had recommended hydroelectric projects as the best source of future electric energy for the four villages. In addition to the hydropower alternative, the continued use of diesel generators, the installation of waste heat recovery equipment, and the installation of wind powered generators were all considered as possible future energy sources. The overall results of these studies indicate that feasible hydroelectric projects can be constructed at King Cove, Old Harbor and Larsen Bay. The study for Togiak indicates that a hydroelectric project of sufficient size to satisfy the overall electric demands is marginal at best and then only if 7.0 miles of the required 11.6-mile access road to the site is con- structed by the Alaska Department of Transportation. It may, however, be possible to construct a much smaller hydropower site near Togiak which would satisfy at least a portion of the electrical needs of the village. This site is currently being assessed at a preliminary level and will be addressed in a later report. NBI-432-9526-SI I-1 Any or all projects studied could be constructed and on- line by January 1985 if a decision to proceed is made by December 1982. B. PURPOSE AND SCOPE OF STUDIES The primary purposes of the studies for King Cove, Larsen Bay and Old Harbor were to prepare recommendations of the best configurations for developing dependable sources of hydro- electric energy supplies for the villages and to determine the engineering, environmental, and economic feasibilities of the projects. For Togiak the primary purpose was to determine if any feasible project could be constructed with the intent to optimize the project features in the next phase if overall feasibility was demonstrated. The general scope of the studies consisted of first projecting the future electrical energy needs of the villages over a 20-year planning period and developing alternative diesel and hydroelectric project scenarios to meet those projections. Increases in demand for energy and the cost of petroleum products were recognized for a 20-year planning period extending from 1982 through 2001. The demands and costs were assumed to be constant after the 20-year planning period. The period for economic evaluation extended 50 years past the on-line date for the hydroelectric alternative. Economic comparisons were then made between these alternatives, the environmental effects were assessed, and conclusions and recommendations were formulated. NBI-432-9526-SI I-2 The diesel alternative for each village was know❑ as the "base case" plan and was essentially a continuation of the present diesel generating plants, enlarged as necessary to accommodate future growth. Heat recovery, to be used for local space heating, was incorporated with the base case plans to the maximum extent that is economically feasible. Wind generation was also considered as part of the base case plan and was found to be economically feasible, although of limited value, at all four sites. Some hydroelectric energy was also used for space heating. I❑ assessing power and energy priorities for the hydroelectric energy for each village, the first priority was given to the direct electrical demand for the village. The second priority, when excess energy was available, was the cannery demand (King Cove only) and the third priority was the village space heating demand. C. OVERALL STUDY RESULTS A table presenting the size, average annual energy generated, the estimated cost (in 1982 dollars), the fuel oil displaced by the hydroelectric energy, and the benefit/cost ratio (B/C) for each project is presented below. The B/C ratios shown reflect the benefits from waste heat recovery, and wind generation and the utilization of excess electrical energy for space heating (and the cannery at King Cove). A more detailed summary is contained in the following sections of this volume: King Cove, Section II; Old Harbor, Sect -ion III; Larsen Bay, Section IV; and Togiak, Section V. NBI-432-9526-SI I-3 Average Annual 1982 Fuel Oil Project Size Energy Cost Displaced/Yr. B/C (kW) ^\J kWh $ (Gal. ) King Cove 575 \ _.2,280,0001. 3,744,90010Yr143,700 2.011 054 Larsen Bay 270 " , 1, 090, 00e, 2, 8;1, 400 °ii0Ap 85,700 1.237 yd Old Harbor 340 0�'L--1,310,000,4`11=3,082,300 �; N' 1039300 1.403 Togiak 432 6iV 2,660,00041119 7,047,200 189,800 1.024 (lid 'CA. i C..'•. 5� 92n°fin The values given above for fuel oil displacement are for a combination of diesel fuel used for diesel generators and space heating. As the B/C values in the above table indicate, the projects for King Cove, Larsen Bay, and Old Harbor are feasible. The Togiak project is marginal. As is presented in the following more detailed summaries for each project, it is possible to derive several different B/C ratios for each of the projects. This is because the calculated B/C ratio for a given project depends on which combination of assumptions concerning waste heat recovery (from the diesel generator), space heating (from the hydroelectric energy in excess of the villages electrical demands) and supplemental wind generators are utilized. For example, the B/C ratios presented above are somewhat lower when the benefit of space heating with excess hydroelectric energy is not included. D. STUDY PARTICIPANTS DOWL Engineers, of Anchorage, Alaska, was the primary con- tractor for the study. DOWL was assisted by two subcontractors- -Tudor Engineering Company of San Francisco, California, and Dryden & LaRue of Anchorage, Alaska. DOWL performed the project management functions and provided all geological, geotechnical, NBI-432-9526-SI I-4 and environmental information. Tudor, as principal subcontrac- tor, supplied all hydroelectric expertise for the project and compiled the project report. Dryden and LaRue formulated the demand projections and supplied all diesel generating and transmission line information. E. ACKNOWLEDGEMENTS The cooperation of the many federal, state, and local agencies and local residents contacted during the course of the study is gratefully acknowledged. This list includes, but is not limited to, the Alaska Power Administration, the Alaska Department of Fish and Game, the Alaska Department of Trans- portation, the U.S. Army Corps of Engineers, the U.S. Geologi- cal Survey, and the U.S. Fish and Wildlife Service. The assis- tance of the Rockford Corporation and the Locher Construction Company, a subsidiary of Anglo Energy Company, is also acknow- ledged. We especially wish to thank the Alaska Power Authority and their program manager for the project, Mr. Don Baxter. NBI-432-9526-SI I-5 SECTION II KING COVE SUMMARY INTRODUCTORY NOTE: Presented in this section is the Summary from Volume B-- Feasibility Study for King Cove Hydroelectric Project. Included for general background information are several items from that report: Exhibit VI-1, Photographs of the Project Area; Figure VII-39 Projected Monthly Generation, Demand, and Usage; and selected project drawings which include Plate I, the General Plan, Plate III, the Penstock Plan, Profile and Details, and Plate VI, the Powerhouse Plans and Sections. References to figures, exhibits, and plates in the summary presented here refer to items in Volume B, the full feasibility report for the King Cove Hydroelectric Project. NBI-432-9526-SKC II-1 KING COVE SUMMARY A. GENERAL Several prior studies of alternative means of supplying King Cove with electrical energy had recommended a hydro- electric project as the best source. As a direct result of these prior studies and recommendations, the Alaska Power Authority authorized a feasibility study to investigate in detail the hydropower potential in the vicinity of King Cove. This report summarizes the activities conducted for the feasibility study. These activities included projections of energy needs, formulation of a hydroelectric project plan and an alternative base case plan to meet the electrical energy needs of King Cove, detailed analyses of economic feasibility of each option, and preparation of an environmental assessment of the effects of the project. The results of the study indicate that a 575 kilowatt (kW) hydroelectric project can be constructed at King Cove, that the project is considerably more economical than the base case alternative, and that the environmental effects of the project are minor. The estimated total construction cost of the proposed King Cove hydroelectric project is $3,743,900 i❑ January 1982 dollars. The project could be implemented and on-line by January 1, 1985, if a decision to proceed with the project is made by December 1982. During an average water year, the proposed project would be capable of supplying more than 90 percent of the electrical needs and some of the space heating needs in the project area. The equivalent savings in diesel fuel in the year 2001 would be about 120,000 gallons for direct electrical demand and 23,000 gallons for space heating. NBI-432-9526-SKC II-2 B. AREA DESCRIPTION King Cove is located on the western end of the Alaskan Peninsula near the beginning of the Aleutian Island chain. With the exception of Cold Bay/Fort Randall 18 miles to the northwest, the nearest major towns are Dillingham, King Salmon, and Kodiak, 300 to 400 miles to the northeast. The selected hydropower site is located on Delta Creek about five miles north of town. The project area and the proposed site are shown on Plate I of Appendix A. C. POWER PLANNING Power planning for the King Cove Project was conducted using standards set forth by the Alaska Power Authority. Previously recommended potential hydroelectric sites were investigated and the project area was surveyed to evaluate potential new sites. After detailed study, a project was selected and then compared with a base case plan. The base case plan consisted of a continuation of the present diesel generation system, enlarged as necessary to meet future growth. The base case also included the installation of waste heat recovery and wind generation. These were both found to be viable for installation. Present energy demands for King Cove for direct electrical uses, cannery use, and space heating were estimated and future uses in these same categories were projected. The projections were based on forecasts of increases in the number of customers and increased usage rates. Population growth and employment, legislation and other political influences, life style changes, and other factors can influence future energy demands but they were not explicitly treated. NBI-432-9526-SKC II-3 The period of economic evaluation used was 53 years, which starts in January 1982 and extends for the 50-year life of the hydroelectric project after the estimated on-line date of January 1985. The energy demands for King Cove were increased for 20 years starting i❑ January 1982 and extending through December 2001. The demands were then held level over the remainder of the economic evaluation period. The cannery demand was assumed to remain constant over the entire period. For the proposed hydroelectric project, it was assumed that the first priority of use for the energy produced would be the direct electrical needs of King Cove, second priority would be for the cannery requirements, and remaining energy would be used for space heating to as great an extent as possible. D. DESCRIPTION OF RECOMMENDED HYDROELECTRIC PROJECT Hydroelectric power plants transform the energy of falling water into electrical energy. Generally, a hydroelectric power project consists of a dam to produce the head or to divert stream flows so that they can be passed through a turbine - generator system to produce electric power. In the case of the recommended King Cove Hydroelectric Project, a low weir will act as a dam to divert water from Delta Creek through an inlet structure and into a penstock (conveyance pipe). The penstock will be 36 inches in diameter and it will carry the water about 5300 feet to the powerhouse, where it will be passed through the turbine -generator system to produce electric energy. The project will incorporate a sediment basin near the diversion weir to trap and remove sediment from, the water before it enters the penstock; otherwise, coarse sediment might damage the turbine. The powerhouse will have the capacity to produce 595 kw of electrical power. A transmission line will be constructed to transmit the power generated at the plant to King Cove. Access NBI-432-9526-SKC II-4 to the powerhouse facilities will be provided by building a new road to link up with the existing road at the King Cove Airport. The transmission line will follow the alignment of the new access road and the existing road from the airport to King Cove. The general plan and features of the proposed project are presented on Plates I through VIII of Appendix A. Photographs of the project area are presented in Exhibits VI-1 and VI-2 at the end of Section VI and in the Environmental Report, Appendix E. Under the recommended plan, energy generated by the hydro- electric plant will have to be supplemented by diesel genera- tion. The entire existing diesel capacity will be required as standby and backup power. The hydroelectric generation will be adequate to meet the direct electrical needs of King Cove (not including the cannery) during most of the year; however, from December through March diesel will be necessary to supplement the hydrogeneration. Diesel will also be needed at times to meet the needs of the cannery located in King Cove. In all, during an average water year the proposed hydro- electric project will be capable of supplying more than 90 percent of the electrical needs of King Cove and approximately one-third of the cannery needs. Average annual energy production from the hydroelectric plant will be 2.28 million kilowatt-hours (kWh) and the average annual plant factor will be about 45 percent, which means that the plant is expected to generate about 45 percent of the energy that it could produce if the turbine -generator unit was operated continuously at full capacity. E. BASE CASE PLAN The base case plan formulated to meet the projected energy demands of King Cove assumed that the existing diesel system NBI-432-9526-SKC II-5 u would continue to be used as the sole source of electric power, excluding the cannery. Because of apparent economic benefits, it was assumed that the system would incorporate waste beat recovery that would be used for space heating. The installation of wind generation equipment was also considered and was found to be economically viable. The existing diesel plant's capacity was judged to be adequate to meet peak demands on the King Cove system throughout the period of study. The diesel system at King Cove now uses about 70,000 gal- lons of fuel oil per year; this rate was expected to increase over the next 20 years to more than 128,000 gallons per year. Waste heat recovery was expected to displace the use of 17,000 gallons of fuel oil per year by the year 2001. F. ECONOMIC ANALYSIS The economic analysis was based on the Alaska Power Authority criteria that compare the net present worth of the base case costs to the net present worth of the proposed hydro- electric project costs using specified real price escalation and discount rates. Net present worth is the present value of the costs that would be incurred over a comparable economic evaluation period of 53 years for both the base case and the hydroelectric project. The net present worth of the total cost of the base case plan is $9,287,000. This net present worth is $8,790,000 after adjustment for waste heat recovery; $8,170,800 after adjustment for wind energy; and $12,983,900 after adjustment for the can- . nery credit. In order to compare all alternatives to the hydroelectric project, all costs other than the cost of the hydroelectric project and its diesel supplement were applied as adjustments to the base case. The net present worth of the base case, after all adjustments, including the space heating credit associated with the hydro project, is $14,203,900. NBI-432-9526-SKC II-6 For the proposed hydroelectric project, the present worth of the costs is $7,053,100. A comparison of these net present costs with the base case net present costs indicates that the recommended hydroelectric project is considerably more economical than the alternative base case. An additional measure of project feasibility is the bene- fit/cost (B/C) ratio. The B/C ratio is the present worth of the project benefits divided by the net present worth of the project costs. For this project the calculated B/C ratio is 1.317 when the hydro project is compared to the base case only, 1.246 when the base case is adjusted for waste heat recovery, 1.158 when the wind energy credit is also considered, 1.841 when the cannery credit is added, and 2.011 when all adjust- ments have been made. The annual unit costs of energy production for the base case and recommended hydroelectric alternatives were calculated for each year of the economic analysis in order to determine the optimum timing for development of the hydroelectric proj- ect. This analysis indicates that the hydroelectric project is viable for immediate development. G. ENVIRONMENTAL AND SOCIAL EFFECTS The environmental study results indicate that the effects of the project will be minor due to the limited scope of the project activities, the lack of major fish or wildlife resources in the immediate area, and the availability of measures to mitigate potential effects from the construction and operation of the facilities. Minor socioeconomic benefits will occur as a result of project construction and maintenance and cheaper electric rates made possible by the project. Additional environmental studies do not appear to be warranted NBI-432-9526-SKC II-7 unless regulatory agencies or local residents express addi- tional concerns. H. CONCLUSIONS AND RECOMMENDATIONS The studies conducted for this report indicate that the proposed 575 kW project is feasible and that the energy demands of King Cove are sufficient to utilize the hydroelectric plant's planned capacity. The proposed project is a more economic means of meeting the area's future electric needs than the base case diesel alternative. Environmental effects of the proposed project are minor. In view of these findings, it is recommended that actions be initiated to implement the project. NBI-432-9526-SKC II-8