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Home My WebLink AboutPreliminary Angoon Alternate Energy Study, Angoon, Alaska, November 1980PRELIMINARY Anwon ALTERNATE ENERGY STUDY ANGOON, ALASKA Prepared for: STATE OF ALASKA DIVISION OF ENERGY AND POWER DEVELOPMENT Prepared by: ROBERT W. RETHERFORD ASSOCIATES A DIVISION OF INTERNATIONAL ENGINEERING COMPANY, INC. ANCHORAGE, ALAKSA NOVEMBER 1980 RWRA - Contract No. 2717 This report has been prepared by Warren L. Enyeart, P.E. Sam F. Fogleman, P.E. ACKNOWLEDGEMENTS We would like to thank THREA for making power requirements for Angoon available for this study and the Alaska Power Authority, who released data from the Thayer Creek Reconnaissance Report, the Preliminary Appraisal Report of Hydroelectric Potential near Angoon and the Hoonah Wood Generation Feasibility Study. Tryck, Nyman and Hayes was very helpful in providing information about Favorite Bay, including a report prepared for Mr. Carroll Martell entitled Angoon Hatchery Concepts. We would also like to thank Mr. Peter Nease who assisted the field reconnaissance crew while in Angoon. CHAPTER PRE ee wn Ww Www wo Ww wy rhH DY LK DY PrP wn Pm wWhNnr BH Ww o www w ow On DD DEPD2/m1 ALTERNATE ENERGY STUDY ANGOON, ALASKA TABLE OF CONTENTS INTRODUCTION AND SUMMARY Introduction Comparison of Alternatives Recommendations ENERGY NEEDS ANALYSIS Existing Facilities Historical Information Estimated Energy and Fuel Requirements Forecast Possible Departures from Estimated Energy Requirements Energy Trade-Offs TIDAL CURRENT POWER GENERATION Potential Power Generation Tidal Current Energy Potential Marine Screw Propeller Power Energy Transmission to the Power Distribution System Comparative Budget Cost Estimates - Alternative 1 vs. 2 Energy Storage Systems Tidal Propeller Unit Marine Structure Tidal Propeller Unit Mooring System Hydraulic Piping to Shore PAGE di i-t ace 2-1 2-1 eae 2-2 3-11. 3-14 3-19 3e2t CHAPTER 3.10 So EL 3.12 preps P wn ow a uot wn NNN NON NWN oP WwW DH HF DEPD2/m2 Tidal Propeller Unit Cost Conclusion for the Angoon Tidal Unit Recommended Project Follow-On FAVORITE BAY HYDROELECTRIC POWER Introduction Hydroelectric Development Cost Sharing with Hatchery Cost Estimate THAYER CREEK HYDROELECTRIC POWER Introduction Hydroelectric Development Cost Estimate WOOD-WASTE GENERATION Introduction Wood-Steam Capital & Operating Cost Estimates ECONOMIC ANALYSIS Introduction Assumption Method of Analysis Project Specifics Conclusion ii PAGE 3-22 3-23 3=23 of 5-4 6-1 6-2 72 Tt es 2 3 tS APPENDICES A. Specific Comments on "Draft Report: Hoonah Generation Feasibility Study" relevant to wood generation for Angoon. B. Power and Energy Requirements for Angoon Cc. Tidal Power: Letters and Drawings D. Economic Analysis: Computer Printouts E. References LIST OF TABLES TABLE PAGE 1-1 Evaluation of Energy Projects 3 2-1 Energy Requirements Forecast 2-3 3-1 Effect of Current Velocity on Power Output 3-4 5-1 Thayer Creek Summary of Firm Power Capacity 5-1 B-1 Energy Requirements Forecast - Summary B-1 B-2 Energy Requirements Forecast - Rural Residential B-2 B-3 Energy Requirements Forecast - Seasonal B-3 B-4 Energy Requirements Forecast - Smal] Commercial B-4 B-5 Energy Requirements Forecast - Large Commercial B-5 B-6 Energy Requirement - Computation Precedures B-6 B-7 Power Requirement - Computation Procedures B=7 B-8 Electrical Heating Requirements B-9 iii DEPD2/m3 TABLE C-1 Energy Production of 2 Tidal Currrent Generators D-1 Economic Analysis - Diesel Generation Only D-2 Economic Analysis - Diesel with Tidal Supplement D-3 Economic Analysis - Favorite Bay with Diesel Backup D-4 Economic Analysis - Thayer Creek Hydro With Diesel Backup D-5 Economic Analysis - Wood waste Generation with Diesel Backup LIST OF FIGURES FIGURE 2-1 Power Requirement Forecast 2-2 Energy Requirement Forecast 3-1 Typical 24 Hour Tidal Current Effects 3-2 Typical 24 Hour Power Output 3-3 Propeller Unit Profile 3-4 Propeller Unit Front View 3-5 Tidal Propeller Unit Mooring System iiii DEPD2/m4 PAGE PAGE 2-4 2-5 3-12 S712 Self 3-18 3-20 CHAPTER 1 INTRODUCTION AND COMPARISON OF ALTERNATIVES Angoon Alternate argy Study Chapter 1 . ; DEPD/h1 1. INTRODUCTION AND COMPARISON OF ALTERNATIVES 1.1 INTRODUCTION Angoon is now at a critical crossroad as far as energy is concerned. Reliable and economical alternatives must be developed. Electrical energy for lighting and appliances is currently generated by diesel- electric generators. The cost of fuel is escalating to the point where alternative, cost-stable energy sources must be found. As a result of several studies, a wide range of alternatives have been evaluated. The ultimate goal is to free Angoon from its dependence on diesel fuel as a primary source (sole source now) of electric energy. Five major alternatives which have been investigated and were found to be generally applicable to Angoon's energy situation include: Tidal Energy Hydroelectric Energy Waste-Wood Energy Diesel-Electric Energy Combination of All of the Above Information available in published reports was evaluated and new energy sources were investigated. One of the most exciting alternatives is tidal power. Strong currents at Turn Point near Angoon can deliver large quantities of environmentally benign secondary energy. Preliminary estimates indicate that tidal energy may be economically competitive with fossil fuel energy. Tidal current energy generation certainly merits further detailed investigation. 1.2 COMPARISON OF ALTERNATIVES The five alternative projects were evaluated relative to each other as shown on Table 1-1. The results show Thayer Creek hydroelectric to be \\ the most effective in meeting Angoon's energy requirements. Angoon Alternate iergy Study Chapter 1 : DEPD/h2 A. THAYER CREEK HYDROELECTRIC It should be emphasized that Thayer Creek also has the potential for future development stages which could be used to provide energy for space heating or other purposes. Full development of the hydroelectric potential of Thayer Creek could completely eliminate the need for diesel- electric generation. The cost effectiveness of developing other hydro sites on Thayer Creek needs to be evaluated in much greater detail. The \ big question is the effect of the Wilderness designation on this project. B. FAVORITE BAY HYDROELECTRIC The Favorite Bay project still has several unknowns. Preliminary investigation showed a possible damsite which should be confirmed by |\ geological investigations. The environmental trade-offs (energy and \ - hatchery project vs. loss of existing spawning grounds) need to be assessed in greater detail. Also, the willingness of the Native Corpor- ation to dedicate their land to this project must be determined. Favorite Bay has the advantage of being a multiple use project - i.e. power generation, potable water supply and hatchery. The project shows limited opportunity for further hydroelectric development upstream. Qe a C. TIDAL ENERGY Because of the R & D nature of this project, it must be viewed with cautious optimism as an energy source. A low reliability factor was assigned because tidal power is untried technology. If a prototype is found to perform as anticipated, tidal power could provide a means to delay the need for other capital intensive investments. Its apparent freedom from adverse environmental effects makes tidal current energy a very attractive alternative. Development of this alternative also shows great promise because its potential applicability to so many different sites in Alaska. ucPD/gL TABLE 1-1 EVALUATION OF ENERGY PROJECTS? Favorite Thayer Bay Creek Diesel Tidal Hydro Hydro Woodwaste 1. Maximizes opportunity for multiple use 2 1 5 4 3 2. Maximizes independence from imported fuel 1 5 3 4 2 3. Minimizes operation & maintenance 2 3 5 4 nl 4. Minimizes environmental effects 4 5 7 3 2 5. Maximizes reliability 3 1 5 4 2 6. Maximizes economic feasibility 3 5 2 1 4 7. Maximizes effectiveness in meeting energy needs 5 z 2 3 4 8. Best meets energy goals oo 3) 4 oo ws Total 21 24 27 28 20 1 A rating of 5 means project most effectively meets evaluation criterion. A rating of 1 means project least effectively meets evaluation criterion. ’ Angoon Alternate rgy Study Chapter 1 DEPD/h4 D. DIESEL The relative advantages and disadvantages of diesel-electric power are ¢ well known. E. WOOD WASTE Wood waste fired generation often looks like a favorable alternative when a low cost for obtaining fuel can be used. Costs can escalate very rapidly and the source of supply can seldom be guaranteed for any time period greater than the short term. Another great difficulty with operation and maintenance of a wood waste plant is the need for highly qualified plant operators. If the supply of wood waste could be guaran- teed for a long term, this alternative could meet all of the energy requirements for Angoon. 1.3 RECOMMENDATIONS i: Proceed with detailed design, construction and testing of a tidal current generator. 2. If two percent financing can be obtained, proceed with a feasibility a ee Soe cae level study of Thayer Creek Hydroelectric Project, to include all damsites on Thayer Creek, with the objective of developing a project which meets a major portion of the total energy requirements of Angoon, including space heating. Favorite Bay hydropower should be considered as a primary alternative. 1-4 I CHAPTER 2 ENERGY NEEDS ANALYSIS [| Angoon Alternate rgy Study DEPD/b1 Chapter 2 7 2. ENERGY NEEDS ANALYSIS 2.1 EXISTING FACILITIES Electrical energy is supplied to Angoon and the surrounding area by the Tlingit and Haida Regional Electrical Authority (THREA), a rural electric cooperative with offices in Juneau, Alaska. Power is generated by small diesel-electric units located in Angoon. There are no transmission interties to Angoon. Following is a list of the generating units serving the community: Angoon Electric System Existing Diesel Generating Facilities Nameplate Capacity, kW Unit No. Unit Total Firm al 300 2 165 3 400 865 465! 2.2 HISTORICAL INFORMATION Limited historical information is available, but enough does exist to establish some trends. The U.S. Census lists a population of 400 in Angoon in 1970. Earlier information is not available from this source. Angoon power and fuel requirements were evaluated in 1977 by Robert W. Retherford Associates as part of an inventory of Southeast Alaska hydro sites. In 1979 Harza Engineering Company prepared an evaluation of Thayer Creek, a part of which included some background information about Angoon. A power requirement forecast was prepared for THREA by the Rural Electrification Administration (REA) in May 1979. This forecast shows per capita consumption as remaining essentially constant with the increase in demand coming from new residential consumers. 1 Firm capacity = Total capacity - capacity of largest unit Angoon Alternate :rgy Study poo) ; DEPD/b2 2.3 ESTIMATED ENERGY AND FUEL REQUIREMENTS FORECAST Energy requirements for Angoon, assuming no electrical heating demand, have been estimated by THREA. These estimates were felt to be applicable and were therefore used in this study. Heating demand for resident consumers will vary quite widely between various sections of town. Some of the newer houses use both wood and oi] heat and all are insulated to HUD standards. The older houses in the center of the village also use a combination of wood and oil heat, but appear to be poorly insulated. Considering the above, an "average per house" heating demand was developed as shown in the Appendix B, Table B-8. Small commercial consumers were estimated to require twice as.much energy for space heat as a residential consumer and the 2 large consumers were estimated to require 96,000 kWh/per year/consumer. Seasonal consumers would require little or no heating energy. Heating energy demands per consumer used in this study are as follows: HEATING ENERGY REQUIREMENT Class of consumer year, allion consumer ear/consumer Residential 16,000 54.6 Seasonal 0 0 Smal] Commercial 32,000 109.0 Large Commercial 96 ,000 327.4 The summary of the results of the energy needs and corresponding fuel requirements analysis is presented in Table 2-1. Energy needs are also depicted graphically in Figure 2-1 and 2-2. A detailed analysis for each class of consumer is shown in Appendix B, Tables B-1 through B-5. Computation procedures used in this study for computing power and energy requirements are presented in Appendix B, Tables B-6 and B-7. 2.4 POSSIBLE DEPARTURES FROM ESTIMATED ENERGY REQUIREMENTS Electrical energy needs would be greatly affected by the construction of a cold storage plant. This project has been discussed for several years 2-2 Angoon Alterna’ Energy Study DEPD/b3 Chapter 2 Table 2-1 POWER, ENERGY AND FUEL REQUIREMENTS FORECAST FOR ANGOON, ALASKA SUMMARY Lighting and Lighting and Appliances Appliances + Space Heating , Fuel int kW MWH kW MWH Gal. x 10-3 1981 242 954 242 954 = 1982 271 1070 271 1070 * 1983 304 ~ 1200 1163 3759 437 1984 309 1217 1181 3823 444 1985 313 1234 1197 3886 452 1986 318 1253 1215 3949 459 1987 322 1271 1231 4013 467 1988 327 1290 1272 4127 480 1989 332 1310 1294 4212 490 1990 337 1329 1319 4316 502 1991 342 1349 1341 4401 512 1992 348 1370 1368 4506 524 1993 353 1390 1412 4633 539 1994 358 1411 1438 4736 551 1995 363 1432 1460 4819 560 1996 369 1454 1486 4922 S72 1997 374 1475 1512 5025 584 1998 380 1498 1563 SL72 601 1999 386 1520 1590 5275 613 2000 391 1543 1615 5378 625 T Fuel to electrical energy conversion at 8.6 KWh/gal. KILOWATTS ANGOON POWER REQUIREMENT FORECAST FIGURE 2-1 INTERNATIONAL ENGINEERING CO., INC. ROBERT W. RETHERFORD ASSOCIATES ANCHORAGE, ALASKA MEGAWAT T - HOURS ANGOON INTERNATIONAL ENGINEERING CO., INC. de Frm ROBERT W.RETHERFORD ASSOCIATES ENERGY REQUIREMENT FORECAST _ - ANCHORAGE, ALASKA FIGURE 2-2 ia Kei i Angoon Alternat nergy Study DEPD/b6 Chapter 2 and no known date has been set for beginning construction. If serviced by THREA, the project would undoubtedly require expansion of the Angoon generation system to provide for the additional load. Another major project on the horizon is a fish hatchery at Favorite Bay. There are still many hurdles to cross before this project is built. It would most likely be constructed as part of the Favorite Bay Hydroelectric Project, discussed in Chapter 4 of this report. This project would require approximately 150 kW peak. and 575, MWh per year. 2.5 ENERGY TRADE-OFFS Due to the absence of any large output hydroelectric projects in the area, there is limited opportunity to take advantage of the early-on excess power frequently provided by hydro projects. It is possible that, if all the hydroelectric power potential available on Thayer Creek were developed, sufficient electrical energy would be available to provide space heating for Angoon. It should be emphasized that, while no cost estimates were prepared for total development of the stream, it is thought that energy from such an extensive development would be quite expensive. Of the alternatives being studied, only diesel, wood-waste, and possibly full development of Thayer Creek could provide sufficient firm energy to meet the electrical demand (See Figures 2-1 and 2-2) created by space heating. Of these alternatives, the only one which meets the goals of (1) eliminating or reducing as much as possible the use of fossil fuels, and (2) is technically proven simple to maintain and operate, is the hydroelectric alternative. Unfortunately, it does not appear that full development of Thayer Creek to provide the firm capacity needed would be economically feasible. However, energy from a two stage development on Thayer Creek, as discussed later in the report, combined with energy from a currently used space heating method such as oi1 furnaces and/or wood stoves installed in the home may prove economically attractive and meet the goals. 2-6 Angoon Alternat nergy Study DEPD/b7 Chapter 2 The following scheme appears to provide benefits and yet avoid most of the problems electric home heating can have for a utility and the homeowner: 1. The homes are built with a conventional heating system plus electric heat. 2. The utility pays for the installation of the electric heat and controls. \ 3. The utility sells the energy for the electric heat at a rate equal or lower than the other heat supply fuel cost. fT 4. The utility is allowed to control utilization of the electric heat - e.g., turn it off during times of peak demand. During these times the "normal" heating system supplies comfort heating for the home. In this way the existing alternate home heating system actually provides peaking capacity to the utility. ‘ 0 “nh ow, A detailed economic analysis of this type of a scheme should be investi- \ vy gated in a follow-on phase. A survey of residents’ acceptance of this rib type of scheme should also be undertaken. Energy for space heating was not included in any of the economic analyses \ presented later in the report. CHAPTER 3 TIDAL CURRENT POWER GENERATION Angoon Alternat nergy Study DEPDa/ 1 Chapter 3 3. TIDAL CURRENT POWER GENERATION Adjacent to Angoon Village is a 350-yard wide channel at Turn Point which interconnects the ocean with a series of broad interior bays extending inland more than ten miles. Thus, a natural structure is created as an ideal hydrological system for producing rapid tidal currents every six hours of the day. The important fishery habitat in the inland bays must not be disturbed such as might occur if a tidal dam were to be constructed across the channel at Turn Point. However, because’of the high average tidal velocities induced near Turn Point, it is not necessary to build a dam to produce power for Angoon. An open type marine propeller could be driven by the tidal currents to produce power from a submerged position in the 42-foot deep channel. This energy conversion unit would be moored by tethered lines near the channel bottom with a minimum clearance above the propeller of 18-feet at mean lower low water level to allow fishing vessels to pass clear of the propeller. Also, whales have been observed in the inland bays and when they would pass nearby, three safety features of the propeller unit would provide for the reduced possibility of impact damage: (1) the propeller would be turning at a slow 30 revolutions per minute; (2) the propeller would be of light weight plastic so that the rotational inertia would be minimal allowing the unit to be easily stopped upon impact; and (3) the outer portions of the plastic blades would be flexible to allow bending upon impact. These three safety features are also beneficial protection against submerged logs and seaweed that may pass nearby the propeller. Along the channel bottom, rocks may be propelled by the tidal currents which reach 10-knots according to the Coast and Geodetic Survey Map 8247 for this region. Therefore, the bottom of the propeller unit would be moored about 4 feet above the channel bottom to avoid impact with the bottom rocks. Routed from the shore out to the propeller unit would be mooring lines and submarine piping which would be rigidly supported and anchored by concrete encasement along the channel bottom. The power machinery of the propeller unit would be enclosed in a metal container to reduce the possiblity of contamination. Angoon Alternat nergy Study DEPDa/ 2 Chapter 3 The propeller and driven machinery would be mounted and supported upon a structural frame of welded pipes with pontoons of hollow pipe members. This marine structure would have an inherent bouyancy to allow the entire unit to float when not tethered onto the channel bottom. When surfaced the unit pontoons would float deep in the water to reduce the pull down load on the tether mooring system as during submergence. Four anchor points near the bottom of the channel would be needed to guide the mooring lines. Whenever the propeller unit requires servicing, the mooring lines would be slackened to allow the inherent bouyancy of the unit structure to float up to the surface. Servicing the unit could be provided from a service boat or by towing to a dockside. The underwater machinery would be the most reliable available so that servicing would need to be as infrequent as is practical. After servicing, by applying tension to the 4 mooring lines, the unit would be resubmerged to be ready for generating power. All components of the propeller unit in operation would thus be normally below the water line - and not visible. Considering the need to solve all of the practical marine problems jisted above, this unit would be one of the most environmentally benign power plants in operation - not visible beyond the shore, without effluents, no foreseeable pollution, and having minimal effects upon wildlife habitat and the local fishery industry. Following are results of alternative studies made to better define the propeller unit. These studies considered determining the best alterna- tive for a power machinery system, the alternative evaluation of energy storage, and a preliminary unit design prepared to allow a budgetary cost estimate to be made for power generation. 3-2 Angoon Alternat: ergy Study DEPDa/ 3 Chapter 3 3.1 POTENTIAL POWER GENERATION OF ANGOON, TURN POINT TIDAL CURRENTS The National Oceanic Survey. (N.0.S.) lists tidal "Current Differences and Other Constants" in Tidal Current Tables 1980, Pacific Coast of North America and Asia as published by the National Oceanic and Atmospheric Administration, U.S. Department of Commerce. Listed in the N.0.S Table 2 as Item 3285, Turn Point, Kootznahoo Inlet, which is adjacent to Angoon Village, are the average velocities for the maximum tidal currents as 6.9-knots flood and 6.1-knots ebb. According to Mr. Richard Meyer, Technician of the N.0.S. office in Seattle, Washington, these average velocities of the maximum currents cannot be extrapolated to find the actual maxima or minima velocities; however they are repre- sentative values averaged over a yearly period. Mr. Meyer stated that detailed N.0.S. data for Turn Point is not available but that the averages given in Table 2 are representative and the best available for use in a preliminary design. Since the tidal currents are constantly changing velocities on an approximate 6-hour cycle, critical judgement is required to select a rating for the power generation design capacity with the highly variable current velocity. As a conservative selection, the reported averages of 6.9 and 6.1 knots were discounted to 6-knots which was used for the design rating of the total propeller output of 300 kW for the tidal energy conversion unit. As an upper limit on the generation equipment, power absorbing capacity 400 kW shaft output was selected to allow for machinery losses. This 400 kW shaft output occurs at a tidal current velocity of 6.6. knots. Table 3-1 was prepared to illustrate the effect of current velocity on power output for two 20-foot diameter tidal propeller units, which could be installed in two phases. 3-3 idan ernat: ergy Study Angoon Alt DEPDa/ 4 Chapter 3 Table 3-1 Effect of Current Velocity on Power Output Theoretical Energy Design Propeller Tidal Available from Power Shaft Manufacturer Current, 2 Propeller Units at Output of Rating for Knots 100% Conversion Efficiency 2 Propeller Units 2 Units 6.6 1169.7 kW 400 kW 6 879.5 300 300 kW 5 508.9 173.6 4 260.6 88.9 3 109.9 37.5 2 32.6 fi. 1 4.07 kW 1.4 kW Considering the decline of power output at reduced tidal velocities, it jis observed that this form of generation would be most valuable as an ‘energy pro System. 3.2 TIDAL ducer to replace fossil fuel generation. Operation as a firm power supplier would be difficult, see Section 3.6, Energy Storage CURRENT ENERGY CONVERSION POTENTIAL Water power calculations for hydroelectric plants commonly use the terms head and quantity of flow to determine the power generation: Where 11.5 P= Qk = nQ x 62.4 PS x 1.025 x .746 FH x eff. = hQ eff. ft 550 ft-Ibs sec is power (in kW) is feed Cin: ft. ) wea each term. is quantity of flow (in cubic ft. per sec. - cfs) is a constant that account for the dimensions used in 1.025 is specific gravity of sea water eff. i iictency of the propel ler-generator-machinery 3-4 Angoon Alternat nergy Study DEPDa/ 5 Chapter 3 ie PURE GEEIEX Q (cfs) x eff Q) A _propeller-generator-machinery unit will convert the velocity of the tidal current into potential head using the classic formula h= 7 (2) Vv: velocity in ft./sec. g: 32.2 ft./sec./sec. Taking the average maximum tidal current of 6 knots (1 knot 5280 ft. x 1.151 = 6076 ft./hr.), the velocity V becomes 10.13 ft./sec. : h = (20.13)? xa2. = 1.59 feet Calculating the area swept by two 20-foot diameter propellers and estimating the maximum power potential at 100% efficiency using the above formula G): 2. Q= Vx area x 2 = 10.13 x 200% 2 — 6364. 87 cfs P= $360. 84489 = 879.5 kW at 100% conversion efficiency At the propeller manufacturer's rating of 300 kW for two 20-foot diameter : aes — 300 kW ratin a wos units the conversion efficiency = 375.5 WW potential = 34.1% efficiency overall. 3.3 MARINE SCREW PROPELLER POWER Since power generation from tidal currents is a new technology, it is necessary to rely on performance data from the closest existing similar technology which is marine screw propeller propulsion. The Angoon Village tidal current unit would have a horizontal shaft mounted to support and receive the power output from a marine screw propeller which is open or unenclosed. Hydroelectric machinery manufacturers have designed and tested numerous power installations with impellers (propellers) that are used alternatively as pumps and then reversed in rotation for use as turbines. Based upon test results they have found that nearly equivalent efficiencies and performance can be designed into an impeller for duty as a pump and as a turbine. Examples of propeller units used as pump-turbines are the plant installations of Argentat and St. Malo in France and Detzem in Germany, although these units are of the enclosed or ducted propeller types. 375 Angoon Alternat “nergy Study DEPDa/ 6 Chapter 3 Summarizing the above experience, use of marine screw propeller (pump) data is justified for predicting the power output performance (as a turbine). Similarly, justification exists for using a power propeller with a reversal of flow direction and shaft rotation as it is exposed alternatively to flood and ebb tides. During this study, letters of inquiry were mailed to 10 propeller manu- facturers for quotations and data input. The best response is included in the Appendix C from a manufacturer whose calculated values for one unit were as follows: Propeller diameter: 20-feet Design velocity : 6-knots Power output : 150 kW or 201 HP at 30 RPM This data can be verified against the Taylor design diagram which is shown in the Standard Handbook for Mechanical Engineers, Baumeister and Marks, 7th edition, McGraw Hill for ship propellers; the following is developed: (pages II-53 through II-58). Bp = a ; power factor (1) and Delta = " , diameter factor (2) Where Bp is power factor N is revolutions per minute P is shaft horsepower Vis velocity, knots d is diameter, feet p is pitch, feet Delta is diameter factor 0.5 Bp = 302% 201 HE zs = 4.82 power factor Delta = 30_RPM x 20 ft. = 100 diameter factor for a 6 knots 3-bladed propeller 3-6 Angoon Alternat ergy Study DEPDa/ 7 Chapter 3 Referring to Figure 3-5, at 4.82 Bp and 100 delta read: propeller efficiency = 745% pitch/diameter = 1.15 projected area = .306 Thus, Figure 3-5 for a 3-bladed propeller is not applicable for Angoon because the projected area is too low by reference to paragraph 3.2 which indicates not less than 0.341 is minimum for conversion efficiency. Thus, a 4-blade propeller is required, 20-foot diameter at 30 RPM to deliver 150 kW shaft power in the 6-knot current. As an alternative, a multibladed propeller may be used provided that the projected area exceeds the value of 0.341. 3.4 ENERGY TRANSMISSION TO THE POWER DISTRIBUTION SYSTEM The tidal current energy conversion unit will be operated in a submerged position near the bottom of Turn Point of Kootznahoo Inlet with the difficult requirement to transmit power ashore to Angoon via the most economical and reliable means available. Two alternative arrangements, both using off-the-shelf designed equipment, apparently could meet these rigid requirements for power transmission. Alternate 1 would consist of a tidal propeller operating at 30 RPM driving a gear reducer with an output speed of either 1200 or 1800 RPM for driving an A.C. induction type electric generator. A submarine power cable would transmit power onto the shore where an A.C. induction motor would rotate in near synchronism with the induction generator. The induction motor would drive a positive displacement type water pump which delivers water to a pressure column for delivery of water to a conventional hydroelectric generator unit with governor-controls and synchronous electric generator for producing power at 60 Hertz, alternating current, feeding into the Angoon power system. 327 Angoon Alternat’ ergy Study DEPDa/ 8 Chapter 3 The submarine mounted generator must be of the rugged induction type for maximum reliability with infrequent needs for servicing. Generator excitation could be provided by one alternative method of an intertie to the existing Angoon electric system. The submarine generator would be "canned" in a sealed air and water tight enclosure. Costs for this Alternative 1 are presented below. Alternative 2 would consist of a tidal propeller operating at 30 RPM directly connected to drive a 30 RPM hydraulic radial type pump. Two 2%-inch size hydraulic oi] pipes with heavy wall thickness would be routed along the channel bottom and run up on the peninsula shore. The oil pipes would be connected to a hydraulic motor with governor to drive a synchronous electric generator for producing power at 60 Hertz, alter- nating current, feeding into the Angoon power system. The submarine mounted hydraulic pump would be enclosed in a sealed container to minimize oi] leakage. Cost for this Alternative 2 is presented below. Both Alternative 1 and 2 systems have omitted, for the time being, the items that would be used for energy storage to levelize the power output during tidal slack water periods. The energy storage systems will be analyzed later. The electrical output to the power distribution system would be derated from the 20 foot diameter propeller unit output by the system and machinery inefficiencies as follows: Angoon Alternat ergy Study DEPDa/ 9 Chapter 3 Alternative 1 - Induction Generator Unit Propeller gear induction submarine induction output x reducer x generator x cable xX motor x eff. eff. eff. eff. positive pipe hydroelectric Derated displacement x line x turb.-gen. = Power pump eff. eff. eff. Output Thus the derated electrical output would be: 150 kW x96 x .91 x .98 x «91 x Prop gear gen. cable motor - 86 x .97 -87 = 84.8 kW, pump pipeline x turb.-gen. Single Unit Net Electrical Output at 6 Knots.................0.. = 169.6 WW, Double Unit Alternative 2 - Hydraulic 0i1 Unit Propeller hydraulic oil hydraulic generator Derated output x pump eff. x line x motor x eff. = Power eff. eff. Thus the drated electrical output would be: 150 kW x -86 x -95 x 86 -x :.91 = 95.9 kW, prop. pump line motor gen. Single Unit Net Electrical Output at 6 Knots .:..... 0... ccciccccececace = 191.8 kW Double Unit 3.5 COMPARATIVE BUDGET COST ESTIMATES - ALTERNATIVE 1 vs.2 The preliminary design of the tidal current conversion unit requires that an economic decision be made to select either Alternative 1 or 2 before proceeding with design of the marine unit structure. The following cost estimates identify only those salient items which would be stand-out differences between the two alternatives. Equipment items were quoted from vendors as budgetary prices with manufacturers names or sources of quotes included in brackets. on9 Angoon Alternat lergy Study DEPDa/ 10 Chapter 3 Aiternative 1 - Induction Generator Unit (200 kW at 6.6 knots and 150 kW at 6 knots) (1) Plastic propeller blades with stainless steel hub (Hartzell) 20-ft. dia., system ...... 270 HP ......... $25,000 ) Reduction gear drive, 270 HP, 40 to 1 ratio (Philadelphia Gear) ....... cee cece cece cece eee $29,500 NO ¢ (3) Induction electric generator, 200 kW, 1800 RPM, (Kato Engineering) with excitation system and controls ...............-.. $ 8,800 (4) Induction electric motor, 250 HP with Circuit breaker... .... kc cee ce cee cece eee eeee $ 4,500 (5) Submarine power cable to shore, 350 lin. ft. Gb S2O/ER ccc saad siete saan sccesd fae cas oes aoe sans 2s. $ 7,000 (6) Positive displacement water pump, 210 HP.............. $ 4,700 (7) Hydroelectric turbine-generator unit derated from the Hidden Falls quotation (Leffel) to 84.8 kW Vaueu Gapatd CVlews.dossce.aeses cass anssacssssasnaousinas $49 ,000 (8) Subtotal budget estimate for single unit generation system 84.8 kW capacity .................. $128 ,500 (9) Total budget estimate for a double unit generation system, 169.6 kW capacity ................ $257,000 or $ 1,515/kW (Not including powerline to Angoon, transformers, marine structure, pipeline, energy storage, floats, moorings, accessories, anchors nor supports. Costs above do not include field cost factors.) Alternative 2 - Hydraulic Oil Transmission System (200 kW at 6.6 knots and 150 kW at 6 knots) (1) Plastic propeller blades with stainless steel hub system 20-ft. diameter, 270 HP CHAT UZEN Toco cicc ce Saciec hs cc08 cmeemandshce ce sweian enw $25 ,000 (2) Radial piston hydraulic oi] pump, 30 RPM, 270 HP (Denison) ............ cece eee eee eee $ 7,600 3-10 Angoon Alternat: ergy Study DEPDa/ 11 Chapter 3 (3) Hydraulic oi1 motor hydrostatic drive type, 220 HP with governor controls (Denison) ....... $13,600 (4) Hydraulic oil piping to shore, 24 inch size, 650 lin. ft. @ $21/LF ... Lk cc ccc cee eee ee $13,700 (5) Electric generator, synchronous type, 60 Hertz, 95.9 kW output, with excitation and controls (Kato Engineering) ............-....-04- $10 , 300 (6) Subtotal budget estimate for single unit generation system 95.9 kW capacity ............. $70,200 (7) Total budget estimate for double unit generation system 191.8 kW capacity ............ 0... eee eee eee $140,400 or : $732/kW (Unit is shop prefabricated and so a field cost factor is omitted. Costs do not include power line to Angoon, transformers, marine structure, energy storage, accessories, floats, moorings, anchors nor supports) Conclusion: These comparative budget estimates show that the hydraulic oi] unit would be lower in capital cost, higher in power output, and therefore is the preferred alternative system around which the marine structure and accessories should be designed. 3.6 ENERGY STORAGE SYSTEMS Figure 3-1 represents typical tidal velocity cycles within a 24-hour day as taken from N.0.S tables. Calculating the propeller output from Table 3-1, the right hand ordinate of kW values was prepared for Fig. 3-1. Figure 3-2 was then prepared to correspond in time with Figure 3-1 with a discount allowance made for the system inefficiencies of the selected equipment in Alternative 2. Figure 3-2 represents the case where the tidal current generators would supply power to the grid in parallel with the existing diesel generators. A diesel generator would float on the line producing low power during high velocities of the current and making up the deficit of power during slack water periods. The tidal current generators would serve primarily as energy contributors for replacing the diesel fuel that might be otherwise used. The levelized 3-11 (MA) LOdLNO TVOTULOATI (M4) LNdLNO YATTAAONd er - € ANdLNO YAMOd YNOH-b2 WIIdAL - ¢-€ “OIA 10}79eJ peoy Ccv* K Weed MA VOE x ot os OOoT 00¢ OGE 00” 8t aWIL et 9 0 Ad INdLNO - oTULOaTA - <QVOI OINLa1a dOVUAAY xO = GazITaAaT =|] LT r NATIAdOUd — LINN-@ Hows - YaMOd WANLXVH dorcel SLOIASA LNAYYAI WOIL YNOH-P2 WOIIdAL - T-€ “Old 8T ANIL eI 9 . QO | ft) +} fit ot os oot 00c Oo€ 00” ($30UY) ALIOOTAA TVGIL (M4) INdLNO UATIAdOUd ’ Angoon Alternat nergy Study DEPDa/ 13 Chapter 3 or average electric load is shown as a constant value of : [304 kW peak load as projected for 1983] x [0.45 load factor] = 136.8 kW average load. This load would vary during time of the day; however, no adjustment is shown because tidal current peak and slack times would progressively vary each day during the year so a time correlation would be meaningless. Pictorially then, Figure 3-2 represents the power generation obtainable without energy storage features. Referring to N.0.S Table 4-A, page 233, at 6-knots maximum current the slack water period between tides is estimated to be 40 minutes for tidal velocities below 1-knot. Using the Hydraulic Oi? System of Alternative 2, a hydraulic accumulator system was conceptually designed to levelize the power output. This accumulator system would be located near the shore mounted hydraulic oil powered generator. Referring to Figure 3-2, the peak generation of 191.8 kW has 55 kW as excess capacity for charging the accumulator for use during slack water periods. At the opposite node of operation the accumulator could limit the diesel contribution to 81.8 kV (136.8 kW load - 55 kW from the accumulator) 136.8 with all operating conditions on the levelized basis. The accumulator would be designed for 55 kW maximum for a 40 minute slack water period; however, using average cyclical values as indicated by Figure 3-2, the accumulator contribution at decreasing kW values would last about 120 minutes per cycle. The accumulator capacity required would be 1850 cubic feet suitable for operation at 3,000 psig maximum pressure. A series of 12-inch, Schedule 100 welded steel pipes would be the most economical arrangement for this accumulator. The accumulator tank battery would consist of 2760 lineal feet of pipe arranged in a bank 15-feet wide x 15-feet high x 110-feet long and would cost: $85.79/lin ft for 12" Sch 100 pipe installed and supported at site x 2760 lineal feet required = $236,780/55 kW = $4,305/kW, an excessive cost which should preclude use of this energy storage system. In confirmation, $4,305/kW for 40 minutes is the equivalent of $6,457.5/kW hour storage, a prohibitive cost. 3-13 Angoon Alternat: “ergy Study DEPDa/ 14 Chapter 3 Energy storage for Alternative I would consist of $1,100,000 water tank system or $5500/kW, also a prohibitive cost. As an alternative, it would be more economical in cost per kW of installed capacity to provide additional propeller units for added incremental kW contributions to the grid while reducing the accumulator bank to a small, low cost system. Refer to the subsequent section on Propeller Unit Cost for the comparative dollars/kW capital cost. In the interim period, as tidal units are progressively added to the system the existing diesel generators would be kept in standby service to make-up for power deficits. 3.7 TIDAL PROPELLER UNIT MARINE STRUCTURE The submerged platform support for a propeller unit would be of relatively simple and low cost construction as shown by Figures 3-3 and 3.4. However, the loads imposed on the structure and the requirements would be varied and complex such as: e Support for weight of propeller, oil pipes and machinery of 10,000 pounds total. e Hollow construction to provide bouyancy for surfacing each propeller unit individually. @ Bouyancy at the surface to be only slightly positive so that when submerged the uplift forces, i.e. 1,500 pounds, would not be excessive when acting on the mooring system. ° Overturning resistance against the machinery torque of about 47,000 foot-pounds, acting alternatively clockwise and counter- clockwise with the reversal of the tides. ® According to the N.0.S. data for Turn Point the tidal current directions upon reversal are 285 degrees and 105 degrees respectively or 180 degrees apart and so the unit may be 3-14 Angoon Alternati ergy Study DEPDa/ 15 Chapter 3 moored in a relatively fixed directional position near the channel bottom. Thus, the moored unit would not be free to swing with slight changes in the tidal current directions. Consequently, the structure should be designed with liberal factors of safety to accept occasional cross currents. e Eddies and whirlpool forces are not anticipated since the unit would be submerged as deep as is practical, i.e. with 18-feet minimum submergence or clearance below mean low lower water level. e Unit to be designed to accept tilting forces of 664,000 foot- pounds from forward and aft directions during maximum momentary tidal currents of 15-knots. e Unit underside supports to hold the main pontoons about 4 feet above the channel bottom to allow rocks and marine life to pass underneath with only minor obstructions. Underside supports must also resist the downward component of the mooring system tension forces. Upon releasing the mooring system tension, occasionally the pointed end of any support may become lodged or wedged between rocks. Consequently, it would be necessary to alternatively tighten and slacken the mooring tensions to free the pointed end. Thus, 1% inch steel plates are used for the support construction, reinforced on the sides with half sections of 8-inch pipes. ° Main pontoons of 36-inch pipe with 3/8" thick walls and filled with lightweight foam for positive bouyancy in the event of wall punctures. Pontoon walls reinforced at junctions with load carrying members. e Mooring tension forces in the pontoon eye bolts would be a maximum of 74,200 pounds at 15-knots maximum current velocity. 3-15 Angoon Alternat ergy Study DEPDa/ 16 Chapter 3 e Corrosion protection for the unit structure would be enhanced by use of pipe of structural members having a minimum of pockets, crevices or recesses. All pipe wall thickness which would tolerate a corrosion allowance of 1/8 to 3/16-inch. Unit structure and all exposed surfaces would be sand blasted and shop coated with either inorganic zinc silicate or an epoxy system. Underwater marine corrosion, lacking exposure to oxygen, is not as severe as surface or waterline type corrosion and thus an impressed voltage cathodic protection system would not be justified. The most severe corrosion exposure would be from abrasion by rocks and sand that could damage the protective coating. Therefore, sacrificial anodes would be mounted on the pontoons. e The unit could be constructed at any shipyard or near any dockside. For ease of transportation the unit could then be towed to Angoon; however, the capability of convenience will not be used to impose any special marine requirements such as the American Bureau of Shipping standards upon the unit con- struction. e The small power capacity of each propeller unit will become the basis to request waiver of any special or unknown govern- mental design requirements for licensing power generation units of this type since existing requirements would hardly be applicable. The marine structure description above applies to a single unit and the loads and requirements would need to be duplicated for a two unit pro- peller installation which would have the two units mounted side by side with their propeller shaft centerlines aligned parallel to the tidal currents. 3-16 Gt Six Bladed Propeller, Two Units Required --—-—— Propeller Hub eee Main Bearing Shaft, 7" Dia. Hydraulic Pump oT Base Plate —-—— Machinery Supports of 12" Pipe Hydraulic Piping Flexible Connection Pontoon End Cap Eye Bolt for / Tether Line : nina Noe al Siurelinne Sa wile Pie be Water Line Pontoon, 3" Dia x CO hts tong ——~ Anchor Plate ait Channel Bottom st -¢€ Propeller, 20 Ft. Dia. Consisting of Two 6 Bladed Units Hydraulic Pump f ares a) Base Plate 4A Machinery wee SSRs \ _ Pontoon: ‘ Eye Bolt Cross Support Channel Bottom ——~ WEN GE Angoon Alternat nergy Study DEPDa/ 19 Chapter 3 3.8 TIDAL PROPELLER UNIT MOORING SYSTEM As with the propeller strucutre, the tidal propeller unit mooring system could be relatively simple as shown in Figure 3-5. Again though, the loads imposed on the mooring system would be varied and complex. The horizontal force acting upon the propeller at a maximum momentary current velocity of 15-knots would be 66,400 pounds and drag forces on the pontoons and structure would be 7,800 pounds resulting in a total of 74,200 pounds basic horizontal force. Each of four mooring eyes and anchor lines would carry this basic load as a safe design to account for accidental unequal or eccentric loading. The mooring lines would be galvanized steel 2-inch diameter cable for the major cable portion and 1%-inch size chain on the ends near the pontoons. Located on the channel bottom would be four critical anchor points for each propeller unit. Each anchor point would secure a 3 inch pin diameter shackle ring for carrying the vertical loads imposed on each mooring cable. Considering the extreme difficulty of doing any construction work on the channel bottom - it has been found that the most practical anchoring points would consist of three each ls-inch rod diameter galvanized steel ground anchors at least 8-foot in length, each which would be drilled and grouted or screwed into the channel bottom, depending on channel bottom material, diagonally opposing angles for maximum holding power. The 3-inch shackles would group the holding power of all 3 screws to vertically guide each mooring cable. Each mooring cable would also have secondary anchors with shackles implaced closer to the channel shore, located so that the mooring cables follow the contour of the channel bottom to minimize becoming an obstruction to boat anchors or moving bottom rocks. At four locations upon the shore would be located the cable end anchors for securing the maximum tension loads. One portable winch unit of 2-ton capacity would be moved to each of the four shore anchor locations for tensioning each mooring cable. The winch would be operated during slack water periods so that the winch capability need not match the load during maximum tidal current 3519 Oc - € eyseTy ‘ucosuy wa3sks BUTA0O_ FUN AeTTEedord TBPTYL - ¢-¢ ‘old INTERNATIONAL Ny COMPANY, INC. Sheet STLLY’_ Contract No.2 Z/ File No. LNT SE. Designed SLOcLH7AN Dato AMV BO Checked Date No LOT PLAN SKETCH No SCALE REFR, DWE! LISCFCS 8247 = eo = 108 fT (PLEATS Faxtt LSCECS E247 ¥ ak SN ‘ 0/ 4 > aN x _ SO TURN %g \/ $6. SP 7 a L % WS SUBMERGED ~ Le * CO Beopctebe ‘rT N\ tC UNITS “= Yy \ 0 | an { \SUBHILECEDP SAL ESUL AINE S VHLAGE. Rick 39 FT RN NAVIGATION LIGHT =~ SOY x 7 cas neon END ANCHORS Mea TIDAL a feos PEOFELL eo Qle- 2B LITE S = ~ ake = iy “ws Xe oe NN U-? . . SURE DNA ae AN 70 SHORE a NX sy YIN oes A AVEDIEL. OS ST ANTE pe h ww7 sD Soup ERCP " LIMES ‘7 ? / / . Ax, My : AWCHPE ot —- 7 Pr ; / spot FOWLL? py Ps GENERATOR. Joye MOORING SYSTEVI_LAYOUT Wo Stake 3 SCHACKLE ; SB . <7 /0"DA “MOORING _7~ = HooP CALLE ™s _-3 -" rf CHANNEL _- - &cvTcr’ HE bi cc L SCREW ANCHORS 14,"DIA «BET LONG. PUNISH, EACH: LYPICAL LINDEPOWATER ANS 2 Angoon Alternatr “nergy Study ’ DEPDa/ 21 Chapter 3 velocities. When the propeller unit is submerged in the operation position, the surplus cable lengths would be coiled onto spools and sorted with weatherproof covers, while the four end anchors carry the mooring tension loads with fixed cable lengths. During servicing operations when the unit is surfaced, the cables would have excessive slack to allow free rise and fall with the tides. The description above applies to a single propeller unit which would allow individual surfacing while a second propeller unit could remain, submerged in service supplying power to the grid. Accordingly, the mooring system description above would be duplicated for a second propeller unit. 3.9 HYDRAULIC PIPING TO SHORE The hydraulic oi] supply and return pipes would run along the channel bottom from the propeller unit about 350 lineal feet to the shore. It is a design objective to require the least amount of field work to install this piping. Prefabricated and pre-tested pipe sections would be sunk in place along the pipe route. Each pipe section would include two 2%-inch size Schedule 160 steel pipes surrounded by wire mesh reinforcing located inside an 8-inch Schedule 20 steel pipe sleeve. The annual spaces outside the 24-inch pipes and inside the 8-inch pipe sleeve would be filled with pumped cement grout and sunk to the channel bottom which ~ would have been precleared of large rocks under the pipe route. The outer 8-inch pipe would have a rubber like protective coating to protect against abrasion. s72L Angoon Alternat: ergy Study DEPDa/ 22 Chapter 3 3.10 TIDAL PROPELLER UNIT COST The following estimate is for a factory fabricated unit consisting of: 2 propellers, hydraulic oi] pump, of 150 kW nominal capacity each $32,600 Roller bearing, Dodge 7" size, 520 lbs wt., 3,700 Propeller shaft 7" dia x 36" long 2,300 Coupling, 7" shaft size 1,300 Pump housing can, 430 pounds 2,200 Baseplate 3/4" x 66" x 54" 3,100 Supports, 12" Sch. 40 pipe, 40 feet at $53.4/Lf 2,200 Cross supports 8" pipe, 48 ft. at $36.4/Lf 1,800 Pontoons 36" pipe 3/8" wall, equiv. of 68 lin. ft. 26,000 Anchor plates 1%" x 60" x 18" avg. x 4 required 5,900 Misc. eye bolts, hardware, bolts, nuts 3,600 Protective coating system 5,000 Shipment cost to site 12,000 Subtotal 101,700 Contingency allowance 15,300 Total propeller unit $117 ,000 Shore mounted hydraulic motor with generator unit, net 95.9 kW net output 23,900 Generator enclosure house 300 sq. ft., concrete pad, fencing, 1.4 Alaska factor 18,000 Subtotal excluding main power transformer, cut-outs and transmission line to Angoon 41,900 Hydraulic piping to shore: Two 2%" Sch 160 lines, 700 lin feet @ $21/lin ft. 14,700 8 inch pipe sleeve with concrete and reinf. steel $37/ft x 650 ft. x 1.4 Alaska factor 33,700 Subtotal $48,400 Total cost estimate for propeller unit- oil lines, shore installed hydraulic generator: 10.1, 10.2, 10.3 not including mooring system, 95.9 kW output 207 , 300 or $207,255/95.9 kW $2162/kW Electrical Intertie to Angoon System: Switchgear (480V), Transformer (150 kVA), and cut-outs $16 ,000 12.5 kV line 3% overhead @ $65,000/mile 21,000 Subtotal $37,000 3-22 Angoon Alternat: ergy Study DEPDa/ 23 Chapter 3 Mooring System: Anchors and Cables $92,000 Contingency @ 15% 14,000 Subtotal $106,000 Subtotal Tidal Power System Construction Cost $350,300 Engineering and Construction Supervision @ 18% 63,100 Total $413 ,400 3.11 CONCLUSION FOR THE ANGOON TIDAL UNIT A conceptual design and cost estimate has been prepared for a relatively simple tidal current power generation unit. The economic analysis presented later in this report shows that this project should warrant further work leading to the construction and testing of a demonstration unit. It was estimated that 2 tidal units could produce 600 MWH per year (Appendix C, Table C-1). 3.12 RECOMMENDED PROJECT FOLLOW-ON Since the economics of this tidal current generator appear to be poten- tially attractive, a low or moderately priced follow-on program may be justified. An intermediately sized single propeller unit of low cost should be constructed in the general configuration as shown in Figures 3-3 and 3-4. A qualified Alaskan test group, such as an engineering division at the University of Alaska, should be employed to test the power output of the unit over the full range of the operating tidal current velocities. The effects of current flow reversal should be measured by reversing the position of the unit. Purpose of the model testing program would be primarily to identify potential operating problems and defects in the unit design. In the interest of low costs there would be de-emphasis of the usual model testing goal of optimum performance measured under scientific conditions. 3-23 Angoon Alternat ergy Study DEPDa/ 24 Chapter 3 Since the resource, flowing water, is relatively abundant there would be little benefit resulting from an optimized hydraulic machinery performance. When interpreting the model test data, should there be any doubt of performance for use in scale-up to a prototype unit, the tips of the propeller blades could be increased in overall diameter to compensate or correct for power shortages. The cost is relatively low for the plastic blades and thus a low-cost test program for model efficiency measurement would be justified. The model test program then, in addition to the modes performance testing, would include tests such as: ° Verify reliability in operation. e Verify the mooring system operation for submergence. e Confirm "canned" housing design for the underwater machinery as an effective barrier against contamination. e Determine existence of unusual and unpredictable vibration, forces or instability of the propeller unit and its mooring system in the submerged operating position. e Setting of the angles of the propeller blades to obtain the desired projected area with an acceptable blade pitch. As a practical matter of model testing, it is usual practice to require a large hydraulic test laboratory with a large volume pumping flow rate to simulate field operating conditions. Likewise, it is usual practice to build a model as large as is practical to eliminate subsequent errors in scale up of the model test data to the prototype final design. The combination of these two factors would require a test laboratory with such a large capacity that availability among existing facilities would be very limited. Therefore as a practical solution to testing under large flow rates with a moderate size model unit, an Alaskan river with velocities ranging from 1 to 10-knots and a depth of 13-feet minimum could serve the purpose intended. 3-24 Angoon Alternat ~ ergy Study DEPDa/ 25 Chapter 3 The propeller model test unit would consist of a design that is modified from the arrangement of Alternative 2, the Hydraulic Oi] Unit which was selected specifically for Angoon Village with a 20-foot diameter propeller. As a compromise, propeller diameter for the model, a four-foot diameter is recommended which would result in higher propeller revolutions per minute. Because of this higher RPM the speed increaser on the propeller output would not have such large losses or cost as analyzed for Alternative 1; therefore the recommended model configuration would be approximately as follows: Propeller: 4-foot diameter & 150 RPM Output: Electric induction type generator, 6 kW capacity normal rated at 6-knots current velocity; 28 kW overload capacity for testing in 10-knot current. Unit width: 5-feet Unit length: 8-feet Unit height: 8.5-feet Power to shore: Submarine electric cable from propeller unit to shore with concrete weights for anchorage to the river bottom. Estimated Cost: An estimate for the model test program has not been prepared. Firm quotations would need to be obtained for fabrication of the test unit and a technically qualified test group from the University of Alaska would also need to be contacted for a quotation of test efforts. 3°25 Angoon Alternat: ergy Study . DEPDa/ 26 Chapter 3 Application: The propeller unit submerged in an Alaskan river or stream could also demonstrate an additional application for remote power gener- ation where building a dam would be otherwise impractical. 3=26 el EB CHAPTER 4 FAVORITE BAY HYDROELECTRIC PROJECT Angoon Alternat: ergy Study DEPDal Chapter 4 4.1 INTRODUCTION Favorite Creek flows into Favorite Bay, which leads to Chatham Strait, at Latitude 57°28'N and Longitude 134°30'W. The drainage basin for the identified hydroelectric site covers 18.5 square miles of Township 51S., Range 68E and Range 69E in the Copper River Meridian. The creek, including the tributaries, is not regulated by any lakes. The Favorite Bay Hydroelectric Project has been conceived as a multiple use project. Components of the project could include power generation, a fish hatchery, and a potable water supply. This project would respond to two urgent social and economic needs, namely a reliable source of cost stable electrical energy without excessive reliance on diesel generation and a source of potable water for Angoon. The project would supply sufficient energy to meet current demands, provided limited use is made of electrical heating. This project could also readily supply the approximately 100,000 gallons per day of potable water required by the residents. The environmental aspects of the project are complex. While it appears that the project would not have serious effects on Favorite Bay, the Bay is a very popular recreation area and is an extremely well used bird gathering area. Salmon spawn in the stream up to and above the proposed damsite. The loss of salmon spawning area could be mitigated by the construction of a hatchery. Several hundred ducks and geese were seen using the tidal flats, and whales and sea lions were observed in the Bay during a reconnaissance of the area. The land where the project would be located has been selected by the Kootznoowoo Village Corporation. According to local residents patent is expected to be transferred within one year. Residents further indicated that they would require very definite information about the project prior to issuing a letter of non-objection. 4-1 Angoon Alternat ergy Study DEPDa2 Chapter 4 4.2 HYDROELECTRIC DEVELOPMENT Dam Axis - A possible dam site exists approximately 2/3 of a mile from the mouth of Favorite Creek. A dam at this location would capture most of the available flow in the creek. The dam crest length would be approximately 300-feet long. The dam height would be approximately 90-feet. While not field verified, inspection of aerial photographs indicated that 2 saddle dikes (less than 20-feet high) would be required in addition to the main dam. Dam Foundation - No known detailed geologic investigation has been preformed in the immediate dam site area. The exposed rock in: the area is sedimentary, metamorphic and conglomerate rock. The area is typically covered with an organic mat one or more feet thick. The stream channel is gravel with some cobbles. The abutments rise at about a 30° angle from the bottom of the channel which is about 70-feet wide. The stream itself is about 50-feet wide at this point. Access to the dam - An existing road from Angoon to Killisnoo would have to be extended about 3 miles to reach the dam site. Compared to much of the terrain in Southease Alaska, the route is fairly flat, allowing for convenient access to both the powerhouse and the dam. Dam Construction Materials - Either a rockfill or an earthfill dam is recommended. Rockfill could be blasted from a nearby quarry area. There are no known gravel deposits large enough and close enough, with rock of quality needed for concrete, to consider concrete dam construction at this site. A gray clay-site deposit was located in the tide flats. It is not known whether this material is physically suitable to use as an impermeable coye in a dam. However, because the material is in the tide flats it is most likely saturated with water which would cause many construction problems. Also there could be some real environmental problems which would need solving before the material could be excavated from the flats. 4-2 Angoon Alternat nergy Study DEPDa3 Chapter 4 Powerhouse Site - A possible powerhouse site was located on the right bank some 1500-feet from the dam site. Above this point the canyon becomes narrower and siting of a powerhouse would be more difficult. The benefits of constructing a powerhouse anywhere other than directly below the dam would have to be carefully evaluated. There would be a trade off between easier siting, access and additional head versus cost of penstock. There would be no tidal influence at either location. Transmission - The transmission line could be constructed along the access road at an elevation of around 100'. The line would be visible from salt water in some places. Many opportunities exist for screening the line. A substation could be constructed approximately 3/4 of a mile from Angoon, where power could be transmitted along existing lines to Angoon and Killisnoo. Environmental - Favorite Creek is catalogued by ADF&G as an anadromous fish stream. Salmon carcasses were observed along the beach. The area is populated by brown bear. Eagle nests would require routing of the transmission line away from the shoreline. Although no petroglyphs were observed during the site investigation, residents stated that they did exist in this area. 4.3 COST SHARING WITH HATCHERY A conceptual layout and design of a hatchery facility at Favorite Bay was prepared by Tryck Nyman & Hayes for Mr. Carrol] Martell in September, 1979. The project would consist of a private non-profit salmon hatchery located on Favorite Bay Creek. The hatchery was planned in such a manner as to become an element of a multiple use project. As a part of this project a private non-profit hatchery permit was prepared. The Favorite Bay hydropower project could provide many benefits and opportun- ities for cost sharing with a hatchery. These include: a reliable source of water; a reliable source of power; joint development of an access road; shared resident quarters; pressure head for operation of hatchery; lower capital costs of hydropower project and hatchery if Angoon Alternate ergy Study DEPDa4 Chapter 4 designed and constructed simultaneously; reduction or elimination of mitigative measures such as fish ladders for the protection of spawning salmon; and joint development of recreational facilities. Reliable Source of Water - The hatchery would require a maximum sustained water supply of 13.9 cfs. Since hatchery water could come from the tailrace of the power plant, there would be no need to construct an impoundment structure specifically for the hatchery. Reliable Source of Power - Remote hatcheries often rely exclusively on diesel fueled electrical generation. Arrangements can be made to supply the hatchery with sufficient dependable reduced rate hydroelectric power. Standby emergency generation would most likely be installed in the hatchery. The hatchery would have a power and energy demand of approximately 150 kW and 575 MWh, respectively. Joint Development of Access Road - This opportunity for cost sharing could be realized if the two projects are constructed simultaneously. This is a major cost item (10% of hydropower project cost) and would improve the feasibility of a hatchery. Road access to Angoon would be a major advantage over water only access for both the hydro project and the hatchery. Shared Resident Quarters - Duplex type quarters could be shared by resident operators of the hatchery and the hydropower project. Other staff would probably reside in Angoon. Water Pressure Head for Operating Hatchery - Approximately 20 feet of static head is normally needed on process water entering a fish hatchery. This pressure is generally developed with electric motor driven pumps. Because of the limited hatchery flow requirements (13.9 cfs) relative to the available flow (75 cfs), an eductor pump placed in the powerhouse tailrace or a fishery line tapped into the penstock could provide the necessary pressure and flow with minimal effect on the energy generating capability of the hydroelectric plant. 4-4 Angoon Alternat: ergy Study DEPDa5 Chapter 4 Lower Capital Costs - Construction materials must be purchased for each project. ‘The opportunity to buy similar materials in larger quantities frequently allows for a lower unit cost. Fish Ladders - Mitigation measures are generally required to allow passage of fish around man-made barriers. If the hatchery is considered as a sufficient mitigative measure, costly fish passage structures on the hydroelectric project would not be required. Furthermore, the need for extensive environmental studies, such as in-stream flow requirement studies would not be necessary. Recreation Facilities - Hydroelectric projects and fish hatcheries are both popular recreation destinations. Facilities would have to be provided for the comfort and safety of visitors. Costs for development of these facilities could be shared. 4.4 CAPITAL AND OPERATING COST ESTIMATE ‘Capital and operating costs for this project were developed based upon an estimate of costs for the major elements of the project. Parameters used in estimated costs included site conditions, location, available work force and availability of materials. While detailed cost estimates were not prepared, it is felt that the cost estimate assigned to this project is representive of a project of this size with parameters as described above. Reservoir clearing costs were felt to be negligible since a contract for sale of timber could compensate for its removal. 4-5 Angoon Alternat: ergy Study Chapter 4 FAVORITE BAY HYDROELECTRIC PROJECT PRELIMINARY COST ESTIMATE Significant Data Drainage Area 18.5 -sq.mi. Est. Ave. Discharge 5.45 cfs/sq.mi. Est. Annual Runoff 73.0 k Ac-Ft Ave. Annual Flow 100 cfs Regulated AS. cfs Capital Costs Mobilization Land and Land Rights 700 acres Reservoir Clearing Diversion and Care of Water Dam - 90 ft. high w/crest 300 ft. long = 110,000 c.y. (incl. grout cap and impervious facing) Spillway - 100 ft wide side channel = 315 c.y.t. - and Intake Waterconductor - Penstock 1,550 ft. long @ 5'o Powerhouse Mechanical & Electrical Equipment Roads - 5 miles Transmission SUBTOTAL DIRECT COST: Contingencies @ 25% TOTAL DIRECT COST Engineering & Administration @18% TOTAL CONSTRUCTION COST: DEPDa6 Mean Effective Head 86° ft. Installed Capacity 800 kW Firm Capacity 425 kW Average Annual Firm Gen. 3,723 MWH Ave. Annual Secondary Gen. 1,226 MWH Ave. Annual Total Generation 4,949 MWH $375,000” 350,000 0 320,000 2,530,000 mar dawn height 135,000 320,000 Soe = _F ), 620,000 tte eons et 650,000 are solely hydvo 500,000 < 6,500,000 1,625,000 8,125,000 1,463,000 Per RWR Hi, Ww dhe beat $9,588,000 Cetin, alte — 1,820,000 bydro ml, optimistic Frynan, 2 4268000 St Geckoge, esak Mexdee Fi ~ hudve shor ein . tonsedn Ass eM CHAPTER 5 THAYER CREEK HYDROELECTRIC PROJECT Angoon Alternate “nergy Study DEPDal Chapter 5 5.1 INTRODUCTION Thayer Creek empties directly into Chatham Strait at Latitude 57°35'N and Longitude 134°37'W. The drainage basin for the identified hydroelectric site covers 62 square miles. A site about 0.2-miles from the mouth of the creek was investigated by Harza Engineering Company and the results reported in a reconnaissance report dated October 1979. Thayer Creek was also evaluated as part of a preliminary appraisal report of hydro- electric potential of several sites by Robert W. Retherford Associates (RWRA) dated September 1977. Both reports were prepared for the Alaska Power Authority. The latter report suggests that, in addition to the Harza sites, another possible site exists 0.75-miles further upstream which could be developed as a second stage. Different design parameters and concepts were used by the two authors to evaluate the capacity of the lower site. Therefore the capacities reported are different. A summary of capacities of the proposed hydroelectric projects on Thayer Creek and the projected power needs (Table 2-1) for Angoon through the year 2000 are presented below. Table 5-1 Thayer Creek Summary of Firm Power Capacity Angoon Requirement (kW) Thayer Creek in Year 2000 Author Firm Capacity (kW) Lighting w/Space Heat Harza 210 RWRA (Stage 1) 575 391 RWRA (Stage 2) 860 860 Total 1070 1435 1615 Keeping in mind that both reports cited thus far on Thayer Creek are reconnaissance level investigations at best, it appears that Thayer Creek could meet a major portion of the energy needs of Angoon, even if electric space heating was installed in the homes; but without additional Sea Angoon Alternat: ergy Study ‘ DEPDa2 Chapter 5 regulation of the stream, it probably cannot meet all of the energy needs. Some other source of energy would still be required. Development of the lower site is discussed in the following paragraphs. However, either or both sites could be developed and further investigation of the upstream site should be completed before any project is constructed on the creek. The RWRA report briefly discusses the potential of raising Thayer Lake a few feet to improve the regulation of the system and thereby increases considerably the firm capacity of the project. This possibility should be investigated prior to commencement of any development of Thayer Creek hydroelectric power potential. The Thayer Creek Hydroelectric Project would not be a multiple use project. Its location, about 6-miles from Angoon, precludes use of the project as a source of potable water. Construction of a dam above the first falls on the creek would not preclude any salmon spawning grounds. Environmental problems associated with construction of the project should be minimal. Aesthetic considerations might arise related to the transmission corridor, which would be visible from saltwater in some places. Admiralty Island has been proposed for Wilderness designation. In some \ wr versions of the legislation establishing the Wilderness designation, \ provision is being made to allow construction of a hydropower project on the island. 5.2 HYDROELECTRIC DEVELOPMENT Dam Axis - A dam site is available approximately 0.2-miles from the mouth of Thayer Creek. Along this reach of the stream, the canyon walls become quite narrow, making the site suitable for a concrete gravity or arch dam. A dam at this location would capture most of the flow in Thayer Creek. The dam would be between 50 and 60-feet high with a crest length of 150-feet. one Angoon Alternat ergy Study DEPDa3 Chapter 5 Dam Foundation - Thayer Creek has eroded a steep sided canyon approximately 300 to 400-feet deep. Stripping of organic material and some shaping of rock cliffs may be required. The dam foundation would be on bedrock consisting of dolomite and green schist with veins of quartz. we Access to Dam - Access to Thayer Creek is by boat from Angoon to the mouth of Thayer Creek. From this point an access road to the damsite would be required. Dam Construction Material - A large quantity of excellent sand and gravel was reported by RWRA near the mouth of the creek. This was not confirmed by the Harza report. No clay has been reported in the area. Powerhouse Site - A possible powerhouse site exists near tidewater. A powerhouse at this location could be founded on bedrock. Water could be conveyed to the powerhouse by either a tunnel or a penstock. Transmission - The transmission line could be constructed following the shoreline at typical elevations of 200-feet or less. A 0.25-mile submarine crossing would be required to reach Angoon. The substation would be Jocated near Angoon, where power could be transmitted along existing lines. It is believed that a messenger-supported insulated cable attached to the trees with occassional wood-pole assistence could substantially reduce costs by practically eliminating the requirement for right-of-way clearing. This method of line construction has been used in other areas of Alaska with sources. Environmental - Thayer Creek is categorized by ADF&G as an anadromous ASV fish stream. A dam would not disturb the passage of anadromous fish as fr a waterfall serves as a natural barrier. The topography is quite steep A in areas of the transmission corridor. The line would be visible from (\e saltwater in several areas. The messenger-supported line design hanging in the trees would be relatively innocuous. 5-3 Angoon Alternate ergy Study ; DEPDa4 Chapter 5 5.3 CAPITAL AND OPERATING COST ESTIMATE As mentioned earlier a detailed preliminary cost estimate for development of Thayer Creek Hydroelectric project was developed by Harza Engineering Company in October 1979. The results of that estimate were increased by 10% to reflect inflation since the preparation of that report and are presented herein. A previous investigation by Robert W. Retherford Associates in September 1977 described an alternate site approximately 3/4-mile further upstream. Either or both sites could be developed. It is recommended that further investigation of this upstream site be undertaken prior to any development on Thayer Creek. The cost estimate for the design proposed by Harza has been inflated at 10% to reflect inflation since the preparation of the report. Angoon Alternat Chapter 5 nergy Study THAYER CREEK HYDROELECTRIC PROJECT PRELIMINARY COST ESTIMATE Significant Data Drainage Area 64.3 sq.mi. Mean Effective Head Est. Ave. Discharge 6.3 cfs/sq.mi. Installed Capacity Est. Annual Runoff 253 k-Ac.ft. Firm Capacity Avg. Annual Flow 405 cfs Ave.Annual Firm Gen Regulated 75 cfs Ave.Annual Secondary Capital Costs” Mobilization Land and Land Rights Reservoir Clearing Diversion & Care of Water Dam Spillway and Intake Water Conductor Powerhouse Mechanical & Electric Equip. Roads Transmission SUBTOTAL DIRECT COSTS Contingencies @ 25% TOTAL DIRECT COST Gen. Ave.Annual Total Gen 1,050,000 102,000 38,000 317,000 2,467,000 312,000 122,000 382,000 740,000 860, 000° 6,390,000 1,598,000 7,988,000 Engineering & Administration @ 18% 1,412,000 TOTAL CONSTRUCTION COST Inflation @10% to 1980 $9,400,000 900,000 Total Construction Cost (1980 $) $10,300,000 7h DEPDaS 45 ft. 400 kW 210 kW 1,839 MWh 1,415 MWH2 3,254 MWH ssuming hydroplant can operate at the installed capacity 85% of the year. 2 Harza Engineering Company Estimate, September 1979. 3 It is believed that this cost cna be significantly reduced by using the messenger - supported cable hanging in the trees. 5=5 CHAPTER 6 WOOD-WASTE FUELED GENERATION Angoon Alternate ergy Study DEPDc/ 1 Chapter 6 6. WOOD-WASTE FUELED GENERATION 6.1 INTRODUCTION The dual purposes of this portion of the Angoon Energy Alternates Study were: e To review the July 31, 1980 "Draft Report: Hoonah Wood Generation Feasibility Study" by six Alaska firms for relevant application to a wood based generation plant for Angoon; and e To provide cost estimates for the construction and operation of the Angoon plant. Specific comments on the Hoonah Draft Report relevant to Angoon are contained in Appendix A. While much of the Hoonah work is roughly applicable to Angoon as a result of geographic proximity, two major items require modification of approach for Angoon: the gasification decision and steam plant operating conditions. First, wood-gas generation is correctly acknowledged in the Hoonah report to require further research and development; wood "gasifiers suitable for particular Alaska conditions" have not yet been designed and built. Demonstration gasification power plants have been reported at relatively low capital costs per installed kW; however, such demon- stration projects require a high level of quality and operational control compared to commercial practice. In order to present a currently realistic case for Angoon, the use of commercially available wood-steam power equipment has therefore been selected in preference to wood-gas power generation with its associated developmental state-of-the-art. Secondly, a wood-steam power plant for Angoon would utilize lower temperature and pressure steam than the Hoonah unit. Discussions with equipment manufacturers have led to the selection of steam conditions of 250 psig and 400-500°F, based chiefly on boiler economics and relative operational simplicity. Angoon Alternat nergy Study DEPDc/ 2 Chapter 6 } The capital cost of a 400 kW wood-fired steam power Plant for Angoon was based on the higher of the two estimates shown below. During the early stages of this investigation, equipment costs were obtained for a 600 kW wood fired steam power plant. The cost estimate for a 600 kW installation was scaled down by 22%, using the "six-tenths power rule," to reflect the lower costs of a 400 kW installation. A 400 kW installation would satisfy the energy requirements of Angoon if no reliance is placed upon electricity for space heating (see Table 2-1). Cost estimates are: 1. A lower 48 turnkey estimate to which 25% was added for Angoon, totalling $1,463,000; and 2. An estimate totalling $1,784,000 based on manufacturer's estimates for boilers and turbine-generator sets, combined with scaling of costs for other major capital items from a recent study for Kake by Robert W. Retherford Associates in 1980. Details regarding capital and operating costs for a wood-waste plant located in Angoon are presented in Section 6.2. 6.2 WOOD STEAM CAPITAL AND OPERATING COST ESTIMATES A. Assumptions Plant size is 400 kW 250 psig, 500°F steam 45% moist wood fuel has 4500 Btu/1b Base year for $ estimates is third quarter 1980. PrP wh 6=2 Angoon Alternate ergy Study DEPDc/ 3 Chapter 6 B. Capital Cost Item Cost, $ Source Boiler and Appurtenances 371,000 Manufacturers' estimates Turbine-Generator-Governor, including Condenser 117 ,000 Manufacturers’ estimates Wood Handling System 195,000 Notes 1,2 Mechanical Auxilaries 156 ,000 Note 2 Electrical Auxiliaries 137,000 Note 2 Civil Works 234 ,000 Note 2 SUBTOTAL DIRECT COST 1,210,000 Contingencies @25% 302,000 TOTAL DIRECT COST 1,512,000 Engineering & Administration @ 18% 272,000 TOTAL CONSTRUCTION COST $1,784,000 Note 1: Includes conveyors, sizing equipment, and stockpile prior to immediate plant use handling system. Note 2: Scaled from a recent RWRA study for a 1500 kW wood-fired steam plant for Kake using a slightly rounded version of the so-called "six-tenths power rule" [Reference: W. H. Comtois; Power Engineering; August 1977]. Cz Labor Cost Steam power plants require skilled operators around the clock; yard equipment and maintenance workers will be required on two shifts. Assume 4 operators at $50,000 per year each and 4 yard maintenance staff at $37,500 per year each for a total (1980 $) labor cost of $350,000 per year. Angoon Alternate ergy Study DEPDc/ 4 Chapter 6 D. Maintenance Cost Use 2.5% of 1980 capital investment cost for 1980 based yearly mainten- ance cost: 0.025 times $1,784,000 equals $45,000 per year. &. Fuel Cost A conservatively efficient wood-fired steam plant could have an overall plant heat rate of 20,000 Btu/kWh. For wood delivered to the plant at $25 per 45% wet ton (as in the Hoonah Draft Report) and an assumed 4500 Btu per ton) the 1980 fuel cost translates to $2.78 per million Btu delivered or 5.56¢/kWh generated. Note that $2.78 per million Btu equates to roughly 39¢ per gallon of 140,000 Btu fuel oil; because of differing plant efficiencies, this comparision is not precise, but it is indicative of fuel cost relatives. Finally, note that this fuel requirement can be viewed as 4.44 lb. wood/kWh generated. 6-4 Angoon Alternat: ergy Study DEPDf1 Chapter 7 7. ECONOMIC ANALYSIS 7.1 INTRODUCTION An economic analysis of five alternatives has been prepared for Angoon. These five alternatives are: diesel generation only; diesel generation with supplementary tidal generation; a wood-waste generation system; Favorite Bay hydro; and Thayer Creek hydro. Inputs central to this analysis are from the "Hoonah Wood Generation Feasibility Study," the "Thayer Creek Project Reconnaissance Report," prepared by Harza Engineering Company, 1979 and recent studies of Favorite Bay and an associated hatchery project. To summarize results of this economic analysis, the present worth of accumulated annual costs through the year 2000, are shown below in 1980 dollars: Alternate Present Worth Diesel $6,102,000 Diesel with Tidal Supplement $5,960,000 Wood-waste $11,295,000 Favorite Bay Hydroelectric $15,132,000 Thayer Creek Hydroelectric $16,136,000 7.2 ASSUMPTIONS Assumptions used in this economic analysis are those recommended by the Alaska Power Authority for Fiscal Year 1981. Inflation Rate - 0% Discount Rate - 3% 2 Petroleum Fuel Escalation - 3.5% OO be wey COO TL Cost of Debt - 8.5% x 7-1, Angoon Alternat ergy Study DEPDf2 Chapter 7 Loan Terms for Dams - 35 years Loan Terms for Diesel and Wood - 20 years Additional assumptions include: Diesel Fuel Cost (1980) : $1.03/gallon (based on most recent THREA fuel purchases) Diesel Lube 011 Costs : 10% of Diesel Fuel Costs (and are included on the Diesel Fuel Cost Line in the computer printouts) Fuel Efficiency : 8.6 kWh/gallon Salvage Value : Amount of Loan remaining to be paid after year 2000 (Straight Line Salvage Value Used) Load : Based on load projected by THREA in the May 1979 report (and used in the Harza Report). No space heating is assumed due to the unavailability of sufficient surplus hydroelectric power. Diesel Generation Plant : $950/kW installed Unit Life of Diesel, Tidal & Wood-waste generation systems : 15 years Unit Life of Hydroelectric Plant : 50 years 7.3 METHOD OF ANALYSIS The alternatives were evaluated on an equal basis. Diesel generation is assumed to be bought new and installed as backup generation during the same year in which the alternative under consideration is installed. For the case in which diesel is the only generation source, the generators are assumed to be installed in 1983 - which is the earliest year in which any of the other alternatives can come on line. To maintain firm capacity it has been assumed that 600 kW of diesel generation would be sufficient. The Tidal Generation System of 192 kW installed in 1983, for example, is backed up by 600 kW of diesel generation. Angoon Alternat’ ergy Study DEPDf3 Chapter 7 The components of annual cost are all shown on the computer printouts (Appendix D). These are: Debt Service; Salvage Value; Diesel and Wood Fuel Costs; and operation and maintenance costs. Labor costs are contained within the operation and maintenance costs. 7.4 PROJECT SPECIFICS A. Tidal Current Energy Construction cost for a 96 kW Tidal Power Generation unit is estimated (see Chapter 3) to be $413,400. It was assumed that two units would be installed, with a combined capacity of 192 kW. 600 MWh has been estimated as usable energy from the Tidal Units. The remainder of Angoon's require- ment would be supplied by diesel units. The assumption of 8.6 kWh/gallon diesel fuel was used. This was established from THREA records for 1978 where 78,900 gallons of fuel where used to generate 676 MWh of energy. Operation and maintenance costs of $29,000 and $67,000 have been assigned to the tidal and diesel systems, respectively. There is some uncertainty about the integration of operation and maintenance functions for the tidal and diesel units. B. Favorite Bay Hydroelectric Project Total unit construction cost for the Favorite Bay Hydroelectric Project is $9,588,000 (See Chapter 4) in 1980 dollars. Favorite Bay has a firm capacity of 425 kW. Of this 425 kW, a maximum of 150 kW would be diverted from use by Angoon consumers to supply the Favorite Bay Hatchery. For that reason 275 kW is shown as the Favorite Bay contribution to capacity. Angoon Alternat nergy Study DEPDF4 Chapter 7 Much of the time, the energy available from Favorite Bay will be great enough to serve the entire Angoon system. It was assumed that no diesel generation would be required to supplement the generation from Favorite Bay. Thus no diesel fuel costs are shown for this case, making the annual costs somewhat conservative. Operation and maintenance costs of $40,000 for Favorite Bay, and $40,000 for the diesel backup have been assumed. C. Thayer Creek Hydroelectric Project A construction cost in 1980 dollars of $10,367,000 (See Chapter 5) is used for Thayer Creek Hydroelectric Project. Annual debt service payments are almost one million dollars. Although Thayer Creek has firm power of 210 kW, it also has considerable secondary energy. It can supply 400 kW about 85% of the time. Thus, little diesel generation is needed. Again no diesel fuel costs are shown for this case. Operation and maintenance costs of $40,000 are used for both Thayer Creek and for its diesel backup. D. Wood-waste Total construction cost for a 400 kW unit is estimated to be $1,784,000 (See Chapter 6). Wood-waste fuel was assumed to be the same as used in the Hoonah Study - 5.56¢ per kilowatt hour. It is assumed that no diesel generation will be needed. Combined operation and maintenance and labor costs for the wood-waste system were estimated to be $395,000 per year. Wood-waste plants require at least one skilled operator on duty for each of three eight-hour shifts a day. Yard workers are also required. 7-4 Angoon Alternat nergy Study DEPDf5 Chapter 7 7.5 CONCLUSION Diesel and tidal are the lowest cost of the five alternatives. It would be feasible to install either system in Angoon. While the economic analysis for tidal was based on installation of two units, no matter how many units are installed, the tidal system would enjoy the same economically competitive relationship with a diesel system. For the wood-waste generation alternative, the operation and maintenance requirements make this system almost prohibitive for a village the size of Angoon. Even if the wood fuel costs were cut in half, this would not offset the large operation and maintenance costs of this system. Both the Favorite Bay and Thayer Creek Hydroelectric Projects are shown in this analysis.to be non-competitive. Accumulated present worth annual costs through the year 2000, show these alternatives to be three times as expensive as the diesel and tidal alternatives. It must be taken into account, however, that the expected life of either hydroelectric project is fifty years - or about three times as great as the lifespan of either the diesel or tidal units. With annual debt service payments for either hydro project of almost one million dollars annually, the payback would not be realized by THREA and the people of Angoon until after the thirty-five year loan has been paid off. We agree with the conclusion of the Thayer Creek Project Reconnaissance Report, that this project is marginally feasible at two percent interest. At eight and a half percent interest, neither hydroelectric project is economically competitive with any of the other alternatives considered. 5 APPENDIX A SPECIFIC COMMENTS ON "DRAFT REPORT: HOONAH GENERATION FEASIBILITY STUDY" RELEVANT TO WOOD GENERATION FOR ANGOON Angoon Alternate 2rgy Study DEPDd/ 1 Appendix A APPENDIX A SPECIFIC COMMENTS ON "DRAFT REPORT: HOONAH GENERATION FEASIBILITY STUDY" RELEVANT TO WOOD GENERATION FOR ANGOON Cover Letter The draft nature of this report is acknowledged. Page No. 14 15 17 Executive Summary Use $25/ton @ 45% moisture as basis for Angoon. Fuel must be barged. Note: "Suitable gasifiers are not mass-produced." Diesel for Angoon was not evaluated in this portion of the study. Environmental Issues Note impact (on freight movement) of petroleum imports. Regarding NSPS for Steam Plants: Angoon 400 kW plant Btu/hr. input rate is an order of magnitude below the 250 x 10° Btu/hr. limit. See p. 17 comment below. The point on cost of particulate cleanup is relevant. Fuel burning equipment for Angoon has estimated input (based on plant fuel rate of 20,000 Btu/kWh) of 8 x 10® Btu/hr. for 400 kW. Angoon Alternate rgy Study DEPDd/ 2 Appendix A Fuel Supply Assume same residue basis and cost applies to Angoon. See separate RWRA wood requirement estimate for Angoon. Guidelines for selection of sites have relevance. Angoon site Note well: "Only one, proven, wood-gasification power generation Note that "gasifiers suitable for particular Alaska condition" have 1000 kW gasifier reported to be ~ 60' high and 8-10' in diameter. Steam system increments more like 1500 kW per recent conversations 5 Page No. Site and Soils 1 requires access to barge landing. Page No. Wood-Gas Power Generation 22 alternative appears to be available." 24 not yet been designed and built. 24 26 Note wood processing requirements. 36 with manufacturers. 38 Two relevant points regarding risks: 1) research and development required for wood gas power; and 2) operator requirements for wood-steam power A-2 Angoon Alternate :=rgy Study DEPDd/ 3 Appendix A Page No. Wood-Gas Power Generation (cont. ) 39 Appended computer printed backup was not available for review. Page No. Wood-Fired Steam Generation 1 Smaller Angoon plant would use 250 psig, 400-500°F steam per discussions with manufacturers. 2 Oversizing comment is relevant. 3. Site preparation at the site would be most economic at times of low local energy demands; this usually quiet time of late night/early morning hours is not ostensibly compatible with the relatively noisy site preparation activities. 3 Btu per pound figure appears to need revision. ~ 9 See separate RWRA cost discussion and estimates. Assumption of costs 25% greater than Seattle also applies to Angoon. A-3 APPENDIX B POWER AND ENERGY REQUIREMENTS FOR ANGOON TABLE 8-1 ENERGY REQUIREMENTS FORECAST FOR ANCOON, ALASKA BASE LOAD PLUS SUACE HEATING SUMMARY OF ENERGY BALANCE COMPONENTS mes : - NEGAWATT HOURS — KILowatTs Heutial RKucal Residential Seasonal Small Conunercial Small Commercial Lacye Commercial Large Conmercial Total ton2l Without Small Large Total Light & Appliances _ Space Heatiny Light & Appliances Light & Appliances Space Heating Light & Appliances _Space Heating | MWh Residential Soace:Meac Comme ccial Comme cial kW 1981 NLA. NA. N.A. N.AL NLA. N.A. NA. 954 NA. N.A. WA. NAA. 242 1982 Md. NA. WA. WA. NLA. NLA. re 1070 N.A. R.A. NA. NA. 2n 1983 577.2 2082.6 86.4 100.8 320.4 400 192 3759 727 152 235 so 1163 1934 592.1 2130.7 86.4 101.0 320.4 400 192 3823 744 152 235 so 1181 1985 607.1 : 2178.7 86.4 101.3 320.4 400 192 3886 760 152 235 50 1197 1935 622.2 2226.8 86.4 101.5 320.4 400 192 3949 776 134 235 - $0 1215 1937 637.3 2274.8 86.4 101.8 320.4 400 192 4013 792 134 235 so 1231 1933 652.5 2322.9 86.4 112.2 361.3 400 192 4127 808 1ss 259 so: 1272 1989 672.3 2387.0 86.4 112.5 361.3 400 192 4212 830 155 259 a 50 1296 1990 696.7 2467.1 86.4 112.7 361.3 400 192 4316 856 154 - | °239 so aio 1991 716.7 2531.2 86.4 113.0 361.3 400 192 Soar 878 154 259 so . 1341 1992 41.3 2611.3 26.4 31903 361.3 400 192 4506 * 905 134 259 a SO - 1368 1993 761.5 2675.3 86.4 123.8 394.2 400 192 4633 926 154 262 so 1412 1995 784.3 2755.4 86.4 124.1 394.2 400 192 4736 953 183 (282 50 1438 1955 £02.6 2819.5 86.4 124.4 394.2 400 192 4819 974 1346 282 50 1460 1955 825.4 2399.6 86.4 126.7 s 394.2 400 192 4922 1000 156 282 50 se86 1937 848.2 2979.7 86.4 125.0 394.2 400 192 5025 1027 153 282 50 1512 1993 871.0 - 3059.8 86.4 : 135.7 427.0 400 192 5172 1053 15% 306 50 1563 1999 893.8 3139.9 86.4 136.0 427.0 400 . 192 $275 1080 154% 306 so 1590 2003 916.6 3220.0 26.4 136.3 427.0 400 192 a nc : wa a) 306 so 1615 DEruvel TABLE B-2 ENERGY REQUIREMENTS FORECAST FOR ANGOON, ALASKA DETAILED ANALYSIS CLASS OF CONSUMER: RURAL RESIDENTIAL Lighting & Appliances Space Heating? Energy Req'd Total Total Energy Req'd Total Total # of Per Consumer MWh/Yr BTU Req'd Per Consumer MWh/Yr BTU Rec’ ° Consumers In_kWh/Month Req'd (10-5) In_kWh/Month Req'd? (x10- 1981 N.A. N iA; N.A. N.A. N.A. N.A. N.A. 1982 N.A. NA. N.A. N.A. N.A. N.A. N.A. 1983 130 370 Sine, 1970 1780 2082.6 7102 1984 133 S71 592.1 2021 1780 21S0R7 7266 1985 136 372 607.1 2070 1780 2178.7. 7429 1986 139 373 622.2 2122 1780 2226.8 7593 1987 142 374 637-3 2173 1780 2274.8 7757 1988 145 375 652.5 2225 1780 2522)..9 7921 1989 149 376 672.3 2293 1780 2387.0 8140 1990 154 37 696.7 2376 1780 2467.1 8412 1991 158 378 716.7 2444 1780 253152 8631 1992 163 379 741.3 2528 1780 2011503 8905 1993 167 380 1615 2597 1780 2675.3 9123 1994 ie 380 784.3 2674 1780 2755.4 9396 1995 176 380 802.6 2737 1780 2819.5 9613 1996 181 380 825.4 2815 1780 2899.6 9886 1997 186 380 848.2 2892 1780 2979.7 10161 1998 191 380 871.0 2970 1780 3059.8 10431 1999 196 380 893.8 3048 1780 3139.9 10707 2000 201 380 916.6 3126 1780 3220.0 10980 1 It is assumed that space heat could begin in 1983 and that all units could be converted at that time. 2 Space heating requires 9 months annually. DErvst1 TABLE B-3 ENERGY REQUIREMENTS FORECAST FOR ANGOON, ALASKA DETAILED ANALYSIS CLASS OF CONSUMER: SEASONAL? Energy Req'd Total Total # of Per Consumer MWh/Yr. BTU Req'd Consumers In_kWh/Year Req'd (X10-&) 1981 NLA. N.A. N.A. N.A. 1982 N.A. N.A. N.A. N.A. 1983 48 300 86.4 295 1984 48 300 86.4 295 1985 48 300 86.4 295 1986 48 300 86.4 295 1987 48 300 86.4 295 1988 48 300 86.4 295 1989 48 300 86.4 295 1990 48 300 86.4 295 1991 48 300 86.4 295 1992 48 300 86.4 295 1993 48 300 86.4 295 1994 48 300 86.4 295 1995 48 300 86.4 295 1996 48 300 86.4 295 1997 48 300 86.4 295 1998 48 300 86.4 295 1999 48 300 86.4 295 2000 48 300 86.4 295 1 There is no space heating requirement for this class of consumer as use is summer only. DEPusni TABLE B-4 ENERGY REQUIREMENTS FORECAST FOR ANGOON, ALASKA DETAILED ANALYSIS CLASS OF CONSUMER: SMALL COMMERCIAL Lighting & Appliances Space Heating? Energy Req'd Total Total Energy Req'd Total Total # of Per Consumer MWh/Yr BTU Req'd Per Consumer MWh/Yr BTU Req'd Consumers In kWh/Month Req'd (x10-°) In kWh/Month Req'd? (x10-! 1981 N.A. N.A. N.A. NA. N.A. NA. N.A. 1982 N.A. Rien: N.A. N.A. N.A. N.A. N.A. 1983 10 840 100.8 344 3560 320.4 1093 1984 10 842 101.0 344 3560 320.4 1093 1985 10 844 101.3 345 3560 320.4 1093 1986 10 846 101.5 346 3560 320.4 1093 1987 10 848 101.8 347 3560 320.4 1093 1988 71 850 tie. 2 383 3560 361..3 1232 1989 ET 832°. 11255 384 3560 301.3 1232 1990 yi 854 1227 384 3560 361.3 1232 1991 11 856 ++" 193,0 385 3560 361.3 1232 1992 Ty 858 143.3 386 3560 361.3 1232 1993 12 860 123.8 422 3560 394.2 1344 1994 12 862 124.1 423 3560 394.2 1344 1995 12 864 124.4 424 3560 394.2 1344 1996 12 866 124.7 425 3560 394.2 1344 1997 12 868 125.0 426 3560 394.2 1344 1998 bE) 870 135.7 463 3560 427.0 1456 1999 13 872 136.0 464 3560 427.0 1456 2000 13 874 1.3 465 3560 427.0 1456 1 It is assumed that space heat could begin in 1983 and that all units could be converted at that time. 2 Space heating required 9 months annually. DErusyi1 TABLE B-5 ENERGY REQUIREMENTS FORECAST FOR ANGOON, ALASKA DETAILED ANALYSIS CLASS OF CONSUMER: LARGE COMMERCIAL Lighting & Appliances Space Heating! Energy Req'd Total Total Energy Req'd Total Total # of Per Consumer MWh/Yr BTU Req'd Per Consumer MWh/Yr BTU Req'd Consumers In_kWh/Month Req'd Gxi0-§) In_kWh/Month Req'd? (x10- 1981 N.A. N.A. N.A. N.A. N.A. N.A. N.A. 1982 N.A. N.A. N.A. N.A. N.A. N.A. N.A 1983 2 200 400 1364 9600 192 655 1984 2 200 400 1364 9600 192 . 655 1985 2 200 400 1364 9600 192 655 1986 2 200 400 1364 9600 192 655 1987 Zz 200 400 1364 9600 192 655 1988 2 200 400 1364 9600 192 655 1989 2 200 400 1364 9600 192 655 1990 2 200 400 1364 9600 192 655 1991 a 200 400 1364 9600 192 655 1992 z 200 400 1364 9600 192 655 1993 2 200 400 1364 9600 192 655 1994 z 200 400 1364 9600 192 655 1995 2 200 400 1364 9600 192 655 1996 2 200 400 1364 9600 192 655 1997 2 200 400 1364 9600 192 655 1998 2 200 400 1364 9600 192 655 1999 2 200 400 1364 9600 192 655 2000 2 200 400 1364 9600 192 655 1 It is assumed that space heat could begin in 1983 and that all units could be converted at that time. 2 Space heating required 9 months annually. " sePENDIX B TABLE B-6 ENERGY REQUIREMENT FOR ANGOON COMPUTATION PROCEDURES i. MWh for rural residential lighting and appliances = # consumers x MWh/consumer/month x 12 months. ! 2. MWh for rural residential space heating = # consumers x MWh/month x 9 months. This is based upon 16,000 kWh/year/consumer for Angoon derived as shown at the end of Appendix 8B. 3. MWh for seasonal lighting and appliances = # consumers x MWh/consumer/month x 6 months.? There is no space heating for this consumer group due to use in the summer season only. 4. MWh for smal] commercial lighting and appliances = # consumers x 12 months x MWh/consumer/month. 4 5. MWh for space heating for the small consumers = # consumers x 9 months x MWh/consumer/month. 6. MWh for large commercial lighting and appliances = # schools x MWh/school/year. ? 7. MWh for large commercial heating = # schools x MWh/school/year for heating. Each School = 6 x requirement of house. Total Angoon energy requirements are the sum of each of these seven groups. 1 T-HREA's May 1979 Summary of Consumers and kWh estimates is the primary source for the above information. ... PENDIX B TABLE B-7 POWER DEMAND FOR ANGOON COMPUTATION PROCEDURES The residential peak power requirement is derived using the formula described in REA Bulletin 45-2, the effect of which is to alter the load factor slightly. Inputs used are the # consumers; the sum of the monthly consumptions in kWh for space heating and kWh for lights and utilities; and a beta factor of .005925. This procedure was used because the relationship between the space heating part of the residential load and the lighting/appliances part of this load are not strictly additive. The commercial and seasonal peak without space heat is derived using an application of REA Bulletin 45-2 on the set of energy balance figures which does not include space heating. For an example year, 1988, the peak requirement for combined residential and commercial light and appliances is 327 kW. For 145 residences using 375 kWh/residence/month and applying the criteria cited in REA Bulletin 45-2, the peak residential demand is 172 kW. The power required to supply commercial and seasonal consumers is the difference between the combined peak power requirement and the residential only peak power requirement. This difference is 155 kW. The commercial and seasonal peak stays about the same through the year 2000. To estimate small commercial space heat requirements, it was assumed that a small commercial building would require twice the energy of a residential building to heat, and that the average resident would require 20 kW for space heating. A coincidence factor of 1.7 was used. «».PENDIX B 4. To estimate space heating requirements for the schools, the calculations of Crews, McInnes and Hoffman, project engineers for the Angoon school, were used. PENDIX B TABLE B-8 ELECTRICAL HEATING REQUIREMENTS FOR ANGOON Heating Degree Days Angoon: 8000 Assume 1000 sq.ft. house R Wall = 11 R Ceiling = 19 ' oO BTU heat loss walls = {4% 31.6’ x 8') (8000 days x 24)_ 17.65 X 10°BTU/year 2 ° BTU heat loss ceiling = (1000 ft") (8000 das x 24) . 10.11 X 10®BTU/year Air Infiltration: Assume 1 air change/hr. BTU Loss Air Change = Cvol(t = ti) x Air change/hr. 3 ' = (90oftn 8 x 8000) . 1 x 24 hrs/day = 27.92 X 106 BTU/year Total BTU/year = 17.65 + 10.11 +29.92 = 55.68 X 10© BTU/year 1 KWH = 3410 BTU 55.68 x 10°BTU = 16328 kWh/year 3410 BTU KWh KWH/yr = Say 16,000 KWH/year per Consumer APPENDIX C TIDAL POWER: LETTERS AND DRAWINGS TMS Rr marine systems & research, 2555 lake drive s.e., grand rapids, mich. 49506, (616) 949-9629 September 22, 19°70 »F. Fogleman » Thermel and native Energy rnational Sngineering Company, Inc. 120 Eoward Street San Francisco, California 94105 Dear Mr. Fogleman: Your known requirements for a propeller to drive an electric generator exposed to a 6 knot tide current is of considerable interest to Marine Systems and Research, We doubt however that a heavy marine-tyve propeller is aporopriate due to its high cost when compar- ed to either a monocogue or composite detachable blade concept which MS 2 R is interested in both designing and manufacturing. Our calculations indicate that a 20' ciameter propeller in a 6 knot flow would be capable of generating 150 kilowatts at 30 rom or if the diameter were increased to 25' approximately 225 kilowatts could be generated exclusive of losses in the generators etc. A shrouded 20' diameter vropeller would be cavable of developing approx- imately 300 kilowatts while also providing protection to the propeller and possibly a means of velocity control main- taining a uniform vropeller sveed; and its this latter concept that interests us most. MS & R has preliminary design date allowing for cetermination of blade angles radially, number of blades and solidity or blade area; and MS & R is vrovosing to provide a preliminary design on both open and ducted con- figurations for a fee of 5000.00 dollars. In addition we further propose to verify our design predictions with model tests conducted at the Ship Hydrodynamics Laboratory at the University of Michigan. All required models will be constructed by MS & R. Cost of models and verification testing is estimated et 5000.00 and 1000.00 dollars respec- tively. The tank tests will require a week of testing. -©. Forleman mber 22, 1930 Final results will be provided three months after receivt of order. Construction drawings and the first prototype would be provided for 50,000.00 dollars (please consider this as a bugitary figure only) and delivered 16 weeks efter design apvroval. : We susvect tnat the above program cen be accomplished for less that one half the cost cf a typical merine propeller with total confidence that your design objectives are met. We hope that our interests and your requirements are compatible and look forwaré to your reply. Sincerely yours, Robert F. Kress Naval Architect SETP marine systems & research, 2555 lake drive s.e., grand rapids, mich. 49506, (616) 949-9629 Mr. S.*. Fogleman Chief, Thermal and Alternative Energy International tngineering Convany, Inc. 130 Foward Street . San Francisco, Cslifornie 94105 Tear Mr. Fogleman: I wish to correct a typographical error in the third paregrapnh of my 22 September letter; that being the cost to conduct model tests estimated to require a week of effort at the Ship Eydrodynamics Laboratory at the University of Michigan. The cost is estimated at 10,000.00 dollars instead of 1000.00 dollars as incorrectly indicated. I am most interested in your comments and reply. Best regards. Sincerely yours, i Robemt FF, Xress Yavel Architect Angoon Alternate ergy Study DEPDe/ 8 Appendix C TABLE C-1 ENERGY PRODUCTION OF 2 TIDAL CURRENT GENERATORS AT ANGOON, ALASKA Over a 3 hour time period: 310 kW (See Figure 3-1) For 24 hours: 310 x 8 = 2480 kWh/day say 250 kWh/day Annual energy output for 1 unit = ono = 450 MWh (@50% load factor) It is unlikely that current velocity will be high enough to regularly provide 450 MWh. So for 2 units it is conservatively estimated that 2/3 of the theoretically available energy can be used: 450 MWh x 2 units x .667 = 600 MWh/year. APPENDIX D ECONOMICAL ANALYSIS: COMPUTER PRINTOUTS OEMAND —- KW ENERGY - MWH EXISTING OLESEL KW ADDITIONAL SOURCES — KW UNIT Lt UNIT 2 UNIT 3 MWH —- DIESEL mMwH - TIDAL DIESEL INVESTMENT (000) TIDAL INVESTMENT (000) OlESEL DEBT SERVICE (000) TIDAL DEBT SERVICE (000) DIESEL SALVAGE TIDAL SALVAGE GALLONS OLESEL FUEL Cost PER GALLON OIESEL FUEL COST (000) OLESEL O&M COST (000) TIDAL O&M COST (000) ANNUAL COSTS PRES WORTH ANNUAL COST ACCUM PRES WORTH A C 1981 242 954 1982 271 1,070 1.10 TABLE 0-1 ALTERNATIVE ENERGY STUDY FOR ANGOON ECONOMIC ANALYSIS DIESEL GENERATION ONLY 1983 1984 198s 304 309 313 1-200 1.217 1.234 800 800 s00 1.200 1-217 1,234 760 - - 80 so so 140,040 142.024 144,003 1.14 tts t22 i ite 184 193 + 39. 39 3° 345 353 362 318 314 312 316 630 942 26.75/ kwh 1986 318 1.253 146.225 1,27 204 so 373 St2 1.254 1987 322 1.271 it 8) 1 143.326 1.38 214 s9 333 Sit 1.565 v 1988 1989 327 332 1.290 1.310 300 s00 1.290 1.310 80 80 150.543 152.877 18, 1.40 225 235 3° 39 394 404 But 310 1.878 2.186 Fl BSH eus\ 1990 337 1.329 155-094 1.45 247 3s? 416 310 2.496 199L 342 1.349 1992 348 1.370 159.879 1.56 274 so 443 Sin 3.117 J 1993 1994 353 358 1.390 1.4tt 300 300 1.390 1,411 so so 162,213 164.664 1.6L 1.67 237 302 3s? 3s? asé 471 Sit Sit 3.423 3-739 32.3 el, 1995 363 1.432 800 ' 1.432 167-114 1.73 313 s? 437 313 4,052 1996 369 1.454 300 1.454 169.632 1.79 334 So3 313 4-365 1997 374 1.475 300 172.133 1.35 350 39 si? 314 4,679 19983 380 1,498 174,817 1.91 367 3s 616 362 5.041 1999 386 1.520 177.334 1.93 336 3s? 635 362 3.403 1,54: 16 60 180.06 2.0 40 1.26 6? 6-10 DEMAND — KW ENERGY — MWH EXISTING DIESEL Kw ADDITIONAL SOURCES - KW UNIT 1 UNIT 2 UNIT 3 mMuUH - OIESEL mWH - TIDAL DIESEL INVESTMENT (000) TIDAL INVESTMENT (000) DIESEL DEBT SERVICE (000) TIDAL DEBT SERVICE (000) DIESEL SALVAGE TIDAL SALVAGE GALLONS DIESEL FUEL COST PER GALLON DIESEL FUEL COST (000) OLESEL O&M COST (000) TIDAL O&M COST (000) ANNUAL COSTS PRES WORTH ANNUAL COST ACCUM PRES WORTH A C 1981 242 954 1.07 1982 271 1.070 ALTERNATIVE ENERGY STUDY FOR ANGOON TABLE D-2 ECONOMIC ANALYSIS v 1983 1984 304 309 1.200 1.217 600 600 192 192 400 617 400 400 570 - s30 - 60 40 ss ss 70.020 72.004 1.14 1.18 ss 93 67 67 29 29 332 337 304 299 304 603 / 24 x y cn 1935 313 1.234 600 192 634 600 60 ss 73.988 1.22 oF 67 29 343 296 899 1936 318 1.253 600 192 653 600 60 ss 76.205 1.27 > 106 67 29 350 293 16192 DIESEL WITH TIDAL SUPPLEMENT 1987 322 1.271 600 192 671 600 73.306 1.31 113 67 357 290 1.482 1988 327 1,290 30.523 1.36 120 67 2 364 2387 1.769 1989 332 1.310 600 2 710 600 60 33 82,857 1.40 123 67 29 372 235 2-054 be 2e.e /nvrn 1990 337 1.329 600 192 vee 600 60 ss 35.074 1.435 136 67 2 3so 233 2.337 1991 342 1.349 600 192 749 600 60 ss 37.408 1.50 144 67 29 388 280 2-617 1992 348 1.370 600 192 770 600 60 ss 39.359 1.56 is¢ 67 398 279 2-896 Vv 1993 1994 353 358 1.390 1.411 600 600 192 192 7990 sil 600 600 60 60 ss es 92.193 94.644 1.61 1.67 163 174 67 67 29 29 407 413 277 “2786 3.173 3.449 29.34 kwh 1995 363 1.432 600 192 832 600 60 ss 97.094 t.72 1835 67 29 429 2735 3.724 1996 369 1.454 600 192 ss4 600 60 ss 99+ S62 1.79 196 67 440 274 3.998 1997 374 1.475 600 192 375 600 60 ss 102,113 1.85 203 67 J 4352 273 4.271 1998 380 - 1,498 600 192 s9s 600 370 830 120 175 104.797 1.91 220 67 29 611 359 4-630 1999 386 1.520 600 192 920 600 120 175 107.364 1.98 234 67 29 625 356 4-936 2000 39 1.543 600 192 243 600 120 173 456 664 110.048 2.05 248 67 ae 1.759 974 3-960 TABLE D-3 ALTERNATIVE ENERGY STUDY FOR ANGOON ECONOMIC ANALYSIS FAVORITE BAY HYDRO WITH DIESEL BACKUP “ v 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 DEMAND - KW 242 271 304 309 313 318 322 327 332 337 342 348 353 358 363 349 374 380 386 391 ENERGY - MWH 954 1,070 1,200 1,217 1.4234 1.253 14271 1.290 1-310 1.329 1,349 1,370 1,390 (1-411 1-432 1.454 1,475 1,498 1,520 1,543 EXISTING DIESEL KW - - - - 600 600 .600 600 600 400 600 600 600 600 600 600 600 600 600 600 ADDITIONAL SOURCES - KW - - - - - - - - - - - - = - - - is - - - UNIT 1 - - - - 275 275 27s 275 275 275 275 275 275 275 275 275 275 275 275 275 UNIT 2 - - = - - - - - - - - - - - - - - - - - UNIT 3 = = = = = 7 = = 7 = Be 7 = 7 - = = = = = MWH - DIESEL - - - - - - - - - - - - - - - - - - - - MWH - HYDRO - - - - 1.234 1.253 1.271 1.290 1.310 1,329 1,349 1.370 1,390 1,411 1,432 1-454 1.475 1,498 1,520 1,543 DIESEL INVESTMENT (000) - - - - 570 - - - - - - - - - - - - - - 570 HYDRO INVESTMENT (000) - - - - 9.583 - - _ - - - - - - -- - - - - - DIESEL DEBT SERVICE (000) - - - - 60 60 60 60 60 60 60 60 40 60 60 60 60 40 60 120 HYDRO DEBT SERVICE (000) - - - - 863 863 863 863 863 8463 863 863 863 863 843 863 863 843 863 $63 DIESEL SALVAGE - - - - - - - aif S = a = e = 7 = = = pei 532 HYDRO SALVAGE ~ - - - - - - - Bs = 7s = = 7 - = = = - 6520 GALLONS DIESEL FUEL - - - - - - - - - - - - a - - - - - - - COST PER GALLON 1.07 1.10 1.14 1.18 1.22 1.27 231 1.36 1.40 1.45 1.50 1.56 1.61 1.67 i739: 3679 1.85 1.91 1.98 2.05 DIESEL FUEL COST (000) - - - - = - - = & = = a ES = = = oa i = ea DIESEL O&M COST (000) - - - - 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 HYDRO O&M COST (000) - = - - - 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 ANNUAL COSTS - - - - 1,003 1,003 1,003 1,003 1,003 1,003 1,003 1,003 1,003 1,003 1,003 1,003 1.003 1,003 1.003 8.115 PRES WORTH ANNUAL COST - - - - 865 840 816 792 769 746 728 703 683 663 644 625 607 sso S72 4.493 ACCUM PRES WORTH A C - - - - 865 1,705 2,521. 3.313 4,082 4,828 5,553 6.256 6,939 7+602 8.246 8,871 9,478 10,067 10.639 15,132 Vv BF Heal 9218 Sew 92%b/lewsly DEMAND —- KW ENERGY -— MWH EXISTING DIESEL KW ADDITIONAL SOURCES — KW UNIT 1 UNIT 2 UNIT 3 MWH - DIESEL MWH - HYDRO DIESEL INVESTMENT (000) HYDRO INVESTMENT (000) DIESEL DEBT SERVICE (000) HYDRO DEBT SERVICE (000) DIESEL SALVAGE HYDRO SALVAGE GALLONS DIESEL FUEL COST PER GALLON DIESEL FUEL COST (000) DIESEL O&M COST (000) HYDRO O&M COST (000) ANNUAL COSTS PRES WORTH ANNUAL COST ACCUM PRES WORTH A C 1981 242 954 1982 271 1,070 ALTERNATIVE ENERGY STUDY FOR ANGOON THAYER CREEK HYDRO WITH DIESEL BACKUP 1983 304 1,200 1.14 TABLE D-4 ECONOMIC ANALYSIS 1984 309 1.217 1.18 1 19sS 313 1.234 600 210 1.234 570 10,300 60 929 1,069 92: 922 1986 318 1,253 600 210 1,253 60 929 1.27 40 40 1,069 895 1.817 1987 322 1.271 600 210 1,271 60 929 1.31 40° 40 1,069 B69 2-686 x 1988 1989 327 332 1.290 1,310 600 600 210 210 1.290 1,310 60 60 929 929 1.36 1.40 40 40 40 40 1.069 1,069 844 819 3-530 4.349 $2.99/ kus 1990 337 1,329 600 210 1,329 60 929 1.45 40 40 1,069 79S 5.144 1991 342 1,349 600 210 1.349 60 929 1.50 40 40 1,069 772 3-916 1992 3438 1.370 1,069 750 6.666 1993 353 1.390 600 210 1+390 60 929 1.61 40 40 1,069 728 7+394 96,4 Iewl 1994 353 1.411 600 210 1,411 60 929 1.67 40 40 1,069 7O7 8,101 1995 363 1.432 600 210 1-432 60 929 1.73 40 40 1,069 686 8.787 1996 369 1,454 1,069 666 9.453 1997 374 1.475 1.069 647 10.100 1998 330 1.493 600 210 1.493 60 929 1.91 40 40 1,069 628 10.723 1999 386 1.520 600 210 1,520 1,069 610 11.3338 2000 391 1,543 600 210 1.543 120 929 532 7-004 2.05 40 40 8-665 4.798 16.136 DEMAND - KW ENERGY — MWH EXISTING DIESEL KW ADDITIONAL SOURCES - KW UNIT 1 UNIT 2 UNIT 3 MWH - DIESEL MWH - WOODWASTE WOOD FUEL ($000) DIESEL INVESTMENT (000) WOODWASTE INVESTMENT (000) DIESEL DEBT SERVICE (000) WOODWASTE DEBT SERVICE (000) DIESEL SALVAGE WOQDWASTE SALVAGE GALLONS DIESEL FUEL COST PER GALLON = DIESEL FUEL COST (000) DIESEL O&M COST (000) WOODWASTE O&M COST (000) ANNUAL COSTS PRES WORTH ANNUAL COST ACCUM PRES WORTH A C 19381 242 954 1.07 1982 271 1.070 ~ ‘ ~ pirrorne TABLE D-5 ALTERNATIVE ENERGY STUDY FOR ANGOON ECONOMIC ANALYSIS WOODWASTE GENERATION BACKED UP BY DIESEL 19s3 1984 304 309 1.200 1.217 600 600 400 400 14200 1,217 67 és 570 - 1.784 - 60 60 ise 188 1.14 1.18 40 40 395 395 750 731 686 467 686 1,353 19ss 313 1.234 600 400 1.234 1986 318 1.253 600 400 183 1.27 40 395 753 631 2.633 19387 322 1.271 600 400 754 613 3.246 v isss 327 1.290 1939 332 1,310 600 400 1.310 1990 337 1.329 600 400 1.329 74 60 183 1.45 40 395 737 563 4.984 1991 342 1.349 600 400 1.349 1992 348 1.370 600 400 1,370 76 60 18s 1.56 40 759 332 6.064 1993 353 1994 358 1-390 1-411 600 400 1,390 77 60 iss 1.61 40 395 760 518 600 400 1,411 761 So3 6.582 7-085 1995 363 1.432 600 400 1.432 763 490 7-575 1996 369 1.454 600 400 1.454 764 476 8.051 1997 374 1.475 1998 380 1.493 600 400 1,498 83 570 1.784 120 376 1.91 40 395 1.014 S96 9.110 1999 336 1-520 600 400 1.520 ss 120 376 1.98 40 395 1,016 379 9.689 391 1.543 600 400 1,543 86 120 376 456 1-427 2.05 40 395 2-900 1.606 11.295 Angoon Alternate = ergy Study DEPDh2 Appendix E bet REFERENCES Federal Power Commission. 1968. Hydroelectric Power Evaluation. U.S. Government Printing Office. Washington, D.C. Galliett, Harold H. et al, 1980. "Draft Report - Hoonah Wood Generation Feasibility Study." Anchorage, Alaska. Harza Engineering Company. October 1979. "Thayer Creek Project - A Reconnaissance Project." Chicago, Illinois. Robert W. Retherford Associates. 1977. "Preliminary Appraisal Report Hydroelectric Potential for Angoon, Craig, Hoonah, Hydaburg, Kake, Kasaan, Klawock, Klukwan, Pelican, Yakutat." Anchorage, Alaska. U.S. Department of Agriculture. 1963. Demand Tables. Rural Electri- fication Administration Bulletin 45-2. U.S. Government Printing Office. Washington, D.C. U.S. Department of Agriculture. May 1979. "Thayer Creek Project =A Reconnaissance Project." Chicago, Illinois.