Loading...
HomeMy WebLinkAboutSupplement To The Elfin Clove Reconnaissance Study 1984 SUPPLEMENT | TO THE ELFIN COVE RECONNAISSANCE STUDY April 1984 Alaska Power Authority__ Mydro/ Wood / Coal /Solar/ Wind /Geothermal/Conservation - SUPPLEMENT | TO THE ELFIN COVE RECONNAISSANCE STUDY April 1984 Alaska Power Authority__ Mydro/ Wood /Coal/Solar/ Wind /Geothermal/Conservation ~ \. | z -RoM AIRPHOTOS TAKEN 6/1/82 ELFIN COVE 2 StALE : |" =/50' (APPROX.) VARIES OVER MAP eas SUMMARY Table 1. Overview of Construction Cost Estimate Component Construction Cost Percentage Breakdown Hydropower System $275 ,000 70% Transmission System 45 ,000 11% Distribution System 75 ,000 19% TOTAL Approximately $400,000 100% 3. Annual Costs. The system's annual costs depend on the financing arrangements. If the project is 100% grant financed, costs would be very low -- approximately $10,000 per year for operation, maintenance, and administration expenses. If the project is financed by loan funds, annual costs coulé& be much greater -- up to a maximum of approximately $50,000 per year. 4. The Next Step - Stream-gaging. If Elfin Cove decides to investi- gate further the Crooked Creek/Jim's Lake hydroelectric system, recording stream gages should be installed on both Crooked Creek and Jim's Lake. The lowest cost for installation and one year's operation of both sites is estimated to be approximately $20,000. 5. Environmental Impact. Preliminary environmental assessment shows that Crooked Creek and Jim's Lake are neither anadromous nor navigable, and neither have resident fish. Consequently, the fisheries impact is probably negligible. Similarly, the impact on terrestrial species is probably limited. Other Potential Hydroelectric Sites No other local streams are suitable for hydroelectric generation. Neither Roy's Creek, Joe's Creek, nor Ernie's Creek are suitable. All have extensive low-flow periods. None have enough water or the useable storage to power an economical, reliable community electric system. ii Table of Contents Page SUMMA WY —secsiw a eicrw wiv alu wie wisiele Wisieo wiviw viwisle swisie wislnie sive esiclewisieeuie sree leiereuereisieiererets i List of Tables .......cccc eee e wees aoe Saisie sists 6 eesls eisiesie SS Vv LISE OF FAQUTOS i ioie:s5s.c:viceisie eiecies 0100 01010: 0.101c 6 clive eieieeivieieecicie ce.eieeeieiscicicee vi Chapter I. INCPOdUCTION ...ccccccccceccccccscseccsvcecenccccesecceonees 1 Ais BaCkG round —:0:0einiainin wie winie 0 minis civic 00.00 01010 0 wisine wisie wsisic ewigee ee 1 B. What's in this Report? ............ ciewe es Cae Seeue sec eees 1 C. Truth-in-Labeling (How good are the estimates?) .......... 2 D. Location and Population ......... hi o:cseierecerers eewiveeWeewure ims—o E. Place Names ........cccecccecceees Tro otro 4 Chapter II. Qnmoow »Y> Chapter III. A. B. Chapter IV. Chapter V. Chapter VI. 524/189 A Community Electric System - Crooked Creek/Jim's Lake .... 6 TACHOMUCET ON ssce o care oo wince 0s oe 6 0.0)e ews esas sas see sss se.cle ss 6 Load Forecast for Elfin Cove ........... ai eiieleYereeiere Fe elele wxeTerstete 7 Electricity Generation Capability ....... wreisterei\sieeiete\o:9jehe016 11 Construction Cost .........00. Wier w eis 016 bisa Wiss Gs Ss Use Sewie eis 15 Annual Cost and Financing .......ccceececccccccsccces weeee 34 What's Next -- Stream-gaging and Other Steps ............. 39 Environmental Impacts and Permits .......cccecceeseoes veae 40 A Community Diesel System .... ccc ccc cc cece ccc ccc cccceves 44 COStSasnwisenives sie wwuicsnicewes PUSS SG SSNS GEeeseeers eas ewes 44 Comparisons Between Diesel and Hydroelectric Costs ....... 45 Other Potential Hydro Sites ........ aXe{e 0 [ol sre keresei eo) stewie eietorere 48 Roy'S Creek ..cccccccccccccccccccsccccecescsccevsseeseeees 48 JOG" SCRE OK 6s sco: o-0:5 Gosia e005 bine s Wee 640s Grsib cules ine sicis esisines 53 Ernte’s Creek: nc cccccciccmessiscwiescenc sisfbi isis ies isielee siete 53 Electricity from the Water Supply System .........esseeeee 54 Wi Navn cise case sais cues wwe u ve cinwassewiesniws ae misewirnemias 58 Table No. w wo On nn 10 11 12 13 14 15 16 List of Tables Page Overview Construction Cost Estimate .......cceeeccceeceees ii Electric Load Forecast - 1988 ..........00- Ha eal UUM 9 Watershed Characteristics for USGS Gaged Streams on Chichagof Island - 1982 ........ cece cece cececcceeece 12 Electric Generation Potential (Jim's Lake & Crooked Creek) 13 Detailed Construction Cost ......cccccccccccccccccccccsces 27 Construction Cost Summary .......... sel etshelel crete! s\sleieialeisis) eis iia'e 33 Loan Amount and Debt Service Requirement .......cceceesees 35 100% Grant Financing - 6.5% Inflation 4... ..seeeecsceeeees 36 60% Grant Financing - 6.5% Inflation ...........ee0- sires vie 37 20% Grant Financing - 6.5% Inflation ............ el avelatesolsi0 38 Financing Arrangements and Cost/KWH ......cceeccceceeeeees 39 Cost for One Year of Operation of Stream Gage ............ 40 Diesel Costs ........ & @islaie lave! /s 016! 6 0/6) 010 s/s) e\Sieie) se (sts16/i0) o/h ieee 44 Diesel vs. Hydroelectric Costs ..... cece cece cece ccccceces 46 Watershed Areas - Streams Near Elfin Cove ......ceeseeeeee 48 Possible Electric Requirements for the Community Center and Docks.......cceeeeeeee ale rel leteielel etehet aia 55 Figure No. On DO F&F WD List of Figures Page Location of E1Fin Cove ......c cece cece cece ccceceeeeeeees - 3 Elfin Cove and Nearby Streams .......cceeeeeeee eiei wfare «1010s 5 Load Forecast 1983-2002 ........cccc cece cc ccnccccccesscece 10 Crooked Creek/Jim's Lake Hydroelectric System ............ 18 Possible Electricity Distribution System for Elfin Cove .. 25 Loan Amount and Debt Service Requirement ...........+-+2205 39 Diesel vs. Hydroelectric Costs ........seeeee sieis €e.n ee terre ste 47 Elfin Cove Watersheds ........ nie sissies ernie eee eeeeeeee cee eeee 49 x vi Chapter I. Introduction Background A Reconnaissance Study of Energy Requirements and Alternatives for Elfin Cove, February 1984, was prepared by a consulting engineer- ing firm on contract to the Alaska Power Authority. A draft of that report was initially distributed in November 1983. At that time, residents of Elfin Cove requested that the Power Authority's efforts include significant information left out of the consul- tant's report. During the process of gathering that information -- including a site visit in February 1984 -- Power Authority staff came to much different conclusions than did the consultant. The original Reconnaissance Report recommends a small hydro facility on Roy's Creek. The Power Authority staff's inves- tigation finds Roy's Creek infeasible and recommends a small hydro project using a stream and lake approximately one mile “further south. This report, Supplement to the Reconnaissance Study of Energy Requirements and Alternatives for Elfin Cove, April 1984, contains the Power Authority staff's analysis. It comes to different conclusions and includes a significant amount of infor- mation left out of the original Reconnaissance Report. What is in this report? This report outlines the options available to Elfin Cove for developing a reliable community electricity system. It focuses on the potential of a small hydroelectric system using the waters from both Crooked Creek and Jim's Lake. The heart of this report is the second chapter which describes that potential system. It outlines the electricity needs of the community, roughly estimates the quantity of electricity available, displays cost estimates, and finally, outlines the next step for the community -- install- ing stream gages. Chapter I. Introduction Other parts of this report briefly describe other options: hydroelectric potential of other streams, generating power from the water supply system, a central diesel facility, and wind. These options are described only briefly because they are for the most part either technically or economically inferior to Crooked Creek/Jim's Lake. While a central diesel facility is a technical- ly feasible alternative, it is one the community is apparently not interested in pursuing. It is included to provide a reference cost for evaluating the hydro-generated electricity. C. Truth-in-Labelling (How good are the estimates?) Estimates of cost, distances, and design: specifications (head, stream flow, etc) are just that -- estimates. They should NOT be interpreted as final costs nor as final designs. Distances and watershed areas were interpreted from aerial photography. Esti- mates of elevation were based on a single altimeter measurement on a day the barometer experienced rapid changes. These estimates will undoubtedly change as repeated and more accurate measurements are taken. Cost estimates are January 1984 costs and are subject to inflation. At the request of the community, the design and cost estimates assume the maximum use of local labor and resources, and the minimum use of expensive design, equipment, and construction tech- niques. We are confident that these estimates provide a reason- able guide for community planning, but readers should be aware that these are local resource, "low-tech" estimates and use them appropriately. Conclusions concerning the electrical generating capability of Crooked Creek/Jim's Lake are based on assumptions about stream flows -- not measurements. They are educated conjectures which can only be confirmed by acutal stream gaging records. Further Chapter I. Introduction investigation of the system should await the stream gaging re- sults. D. Elfin Cove - Location and Population. Elfin Cove residents already know the location and population of their community. For others, that information follows. Elfin Cove is located approximately 65 air miles west of Juneau on the northern end of Chichagof Island, as shown in Figure 1. Popu- lation varies seasonally, from a winter low of approximately five to eleven households (plus community building and store), up to 24 households, plus an inn/cafe, a laundromat, and a second store during the height of the summer fishing season. Figure 1. Location of Elfin Cove Chapter I. Introduction Es Place Names. In reporting the hydroelectric investigations for Elfin Cove, we have to reference many landmarks that are un-named on topographic maps. Whenever possible, we have attempted to use local names for these landmarks. The names used in this report can be seen in Figure 2. Figure 2 ELFIN COVE powos ay S - Approximate yoe> location of CREEK creek water sUPPY 6 é 9 * € & ool” are WY A \ KW \ \ AX ta WN M9 \S (Apprommate) Details Toren from 1982 oerio! omotography Chapter II. A Community Electric System Crooked Creek/Jim's Lake Introduction This chapter outlines the potential for a community electric system powered by water from Crooked Creek and Jim's Lake water- shed. A full analysis of the system requires knowledge of the physical ability of those watersheds to supply electricity, the amount of electricity required to service Elfin Cove, and the electricity's cost. This chapter provides that information. It ‘provides a detailed conceptual design for a hydro system, the construction and operating costs, and -- if the community is interested in further investigation -- what next steps it should take. Crooked Creek is approximately one mile south of Elfin Cové. “Its drainage area measures slightly more than one-half square mile and it flows into a pronounced inlet on Port Althorp. The creek differs from other nearby creeks in that it rarely, if ever, dries up. One older local resident reported that in his 30 years of observation, he had never seen it run dry or completely freeze up. By itself, the stream has limited potential for generating elec- tricity. The watershed has no storage and there is no obvious place where a small dam could create significant. storage. The maximum power it can generate is limited to its flow at any moment; whatever is in the stream at any instant is the maximum useable water. Just south of Crooked Creek and 1,700 feet from Port Althorp lies an unnamed lake which, for this report, is being called Jim's Lake. The lake's surface area is approximately four acres and its depth is reported to be up to 24 feet. The watershed surrounding Chapter II. A Community Electric System the lake is exceptionally small - just less than 0.1 square mile. Thus, the lake is probably replenished slowly by its surroundings. The lake surface is approximately at the 350 foot elevation level. A hydroelectric system beginning at the lake could generate quite a lot of power until the lake went dry. Then, because the water- shed is small and the lake will be replenished slowly, electricity would be unavailable for a few days or weeks until the lake refilled. Neither Crooked Creek nor Jim's Lake on their own can support an appropriate hydroelectric project for Elfin Cove. Together they appear to make a feasible project. Jim's Lake provides the storage and Crooked Creek provides the water source. If Crooked Creek were diverted into Jim's Lake and the combination used for generating power, there appears to be more than enough water and storage to provide all of Elfin Cove's power requirements, prob- ably even during normal winter and summer low-flow periods. These conclusions, however, are based on assumptions about streamflow -- not actual measurements. B. The Load Forecast To evaluate the potential of the Crooked Creek/Jim's Lake system, it is necessary to know how much electricity the town needs. According to the consultant's Reconnaissance Report: Elfin Cove residents presently practice a very high degree of electric energy conservation: they simply use very few electrical devices. Most homes use electricity for a few lights and perhaps a CB radio. Even though no television stations can be received in Elfin Cove, some homes have tele- vision, either for use with VCR's or video games, a few other homes have washing machines. Even with Chapter II. A Community Electric System no central utility, it can be expected that the per-household use of electric energy in Elfin Cove will increase in the future. This growth is expected to be very slow. If a centralized system is installed which makes electricity available at the flip of a switch, the increase in electricity use can be expected to be much more rapid. This effect is to be expected regardless of the source of the electric power (diesel, hydro, wind, etc.).! A full load forecast is contained in the-Reconnaissance Report, but a summary of projected near-term electrical use -- assuming a central utility and some per kilowatt-hour charge -- is in Table 2. Long-term electric use forecasts appear in Figure 3. Ls Reconnaissance Study of Energy Requirements for Elfin Cove, February 1984, page 15. Chapter II. A Community Electric System Table 2. Electric Load Forecast - 1988 Residential Use - 1988! Summer (May to September) Monthly Energy Use 28 Homes X 230 KWH/month per home = 6,400 KWH/month Peak Power Demand 28 homes X 1.7 KW X 8 = 38 KW Winter (October to April) Monthly Energy Use 7 homes X 315 KWH/month per home = 2,200 KWH/month Peak Power Demand 7 homes X 2.2 KW X 0. 8” = 12 KW. Commercial Use - 19882 LOAD SUMMER LOAD = WINTER LOAD General Store TO KW 1,800 KWH/Mo 10 KW 1,440 KWH/Mo General Store 10 1,800 0 0 Machine Shop 20 1,150 20 800 Inn 3 540 3 540 Laundromat 3 430 0 0 Telephone System 3 216 3 216 Community Building 2 30 2 30 | TOTALS 5I KW 5,966 KWH/Mo 38 KW 3,026 KWH/Mo X.6(diversity) Xx. 6 (diversity) “3ST KW “23 KW Summary Summer Winter KW KWH/Mo KW KWH/Mo deo a g, e - a a Commercia TOTAL eee KWH/Mo San KWH/Mo * 0.8 is a diversity factor. It reflects the fact that it is unlikely that all households will require peak power at the same time. 1. Taken from Reconnaissance Report. Table 11, p. 43 2. Taken from Reconnaissance Report. p. 29 Figure 3. Load Forecast 1983-2002 Taken from Reconnaissance Report, pages 45 and 46) ELFIN COVE POWER OEMANO FORECAST TOTAL ANNUAL PEAK POWER DEMAND (kW) 2002 160 -______-. ex FIN COVE ENERGY USE FORECAST (with uTIUTY) 140 120 8 ANNUAL ENERGY USE (1000 x kWh) 8 TOTAL 60 use 40 zo |__| __|_ p_commeraat, use ° 1963 1968 993 we 2002 10 Electricity Generation Capability The amount of electric power a hydroelectric system can produce depends on the amount of water available and the head. Head is the elevation difference between the source area and the power- house. In the case of Jim's Lake, because the powerhouse will be just above the high tide level, the available head is simply the elevation - 350 feet. Estimating the quantity of water available is more difficult. There are no discharge records for any local streams. It is possible to make an extremely rough estimate of discharge by comparing the drainage areas for local streams with the unit discharge for gaged streams on Chichagof Island. (Unit discharge is the discharge per square mile of drainage area.) The U. S. Geological Survey (USGS) maintains four discharge stations on Chichagof Island. For their watershed characteristics, see Table 3. Although Crooked Creek and Jim's Lake watersheds are much smaller than those listed above, it seems reasonable to guess that Crooked Creek and Jim's Lake watersheds contribute, on average, somewhere in the range of 5-8 CFSM to their creeks. Similarly, the lowest winter month's flow is estimated at approximately 1 CFSM and the lowest summer month's flow at approximately 1.5 CFSM. Using those assumptions, the streams' potential power is calculated in Table 4. 11 Table 3. Watershed Characteristics for USGS Gauged Streams on Chichagof Island - 1982! Drainage ‘Area Mean Minimum CFSM2 : ; 3 STREAM (Sq. miles) CFSM2 Winter~ Summer Black River near Pelican 24.7 7.98 2.02 4.45 Kadashan River Above Hook Creek 10:2 6.06 1.07 1.89 near Tenakee Tonalite Creek near Tenakee 14.5 6.06 1.06 1.52 Indian River near Tenakee 12.9 5.30 1.07 1.46 NOTES: 1. 1982 is the latest year for which records have been pub- lished. 2. CFSM is cubic feet per second per square mile of drainage area. For example, a stream with a two-square mile drainage area which has mean annual CFSM of two would annually dis- charge an average of four cubic feet per second. 3. Lowest monthly CFSM falling between September and April. 4. Lowest monthly CFSM falling between May and September. 12 Table 4. Electric Generation Potential Jim's Lake Watershed Only Available Water Available Power and Energy Mean Mean Mean Power Mean Monthly Watershed Streamflow! Available Energy? Flow-CSFM CFS KW KWH/Month 3 0.28 6.5 4,700 4 0.37 8.7 6,300 6 0.55 13.1 9,400 8 0.74 17.5 12,600 Lake Watershed plus Crooked Creek-Watershed Available Water Available Power and Energy Mean Mean Mean Power Mean Monthly Watershed Streamflow! Available- Energy? Flow-CSFM CFS KW KWH/Month 3 oe 39.4 28,400 4 2.2 52.5 37 ,800 6 3.3 78.8 56,700 8 4.4 105. 75 ,600 Summer 1.5 -83 19.6 14,100 Winter 1 ~55 13.1 9,400 NOTES: 1. Jim's Lake Watershed estimated at 0.09 square miles; Upper Crooked Creek Watershed estimated at 0.46 square miles; and the combination at 0.55 square miles. p= He id. where Q = streamflow in CFS (from column two) H = e= P= Net Head in feet (330 feet allowing for 20 feet of head loss along the penstock) Overall efficiency of the turbine - generator system (65% or 0.65) Power in KWH KWH/Month = KW X 720 hours/month 13 The mean power available is not peak power. Due to the signifi- cant storage capacity of Jim's Lake, it would be possible to generate a very large amount of power for a very short time. For example, it would be possible for the system to generate 500 KW, but the lake would go dry within hours. The more important question is, can the system generate the required amount of energy without running the lake dry? The answer to this question is found in the KWH/Mo estimate, not in the mean or maximum KW estimate. If the energy is available to service Elfin Cove, it can be supplied under most any schedule. For example, 500 KWH can be generated at 500 KW for one hour or one KW for 500 hours. Because of the storage in Jim's Lake, the monthly energy require- ment is more important than the instantaneatis power requirement. From the calculations in Table 4, it appears that the Jim's Lake watershed alone cannot generate enough energy to supply the majority of Elfin Cove's power requirements. If a small hydro facility were built using only the water from Jim's Lake~water- shed, it would not be able to supply any power during the winter and summer low flow periods nor during any period of prolonged energy use. Jim's Lake watershed by itself is not an appropriate hydro project. If the Upper Crooked Creek were flumed into Jim's Lake, and the combination used for generating power, there appears to be more than enough water to provide all of Elfin Cove's power require- ments even during normal winter and summer low-flow periods. 14 Construction Costs This section provides a construction cost estimate for the total hydroelectric system: generation, transmission, and distribution within the community. Both the cost estimate and the design require some explanation, however. What do the costs include? How reliable are the costs? The explanation is below. It is followed by a detailed breakdown of the system's projected con- struction cost. Explanation of Costs The cost estimates below are rough. They are January 1984 costs subject to inflation and are based upon maximum use of local labor and resources. Distances outside the townsite were estimated from high altitude air photos. Distances within the Cove itself were determined from low altitude photography. Watershed areas were interpreted from high altitude photography. Estimates of ele- vation were based on a single altimeter measurement on a day- the barometer experienced rapid changes. The distances and elevation estimates will undoubtedly be revised as repeated and more de- tailed measurements are taken. As requested by the community, the cost estimates assume the maximum use of local labor and resources and the minimum use of expensive design, equipment, and construction techniques. For example, it is assumed that the diversion dam would be made from local materials: wood and rock. It is, of course, easy to design a more expensive, stronger dam which requires less maintenance and would last longer (concrete, steel, piling, etc.), but log crib or rock-filled dams have proven reliable and strong. They do require a little more maintenance, however. These “low-tech" designs are less expensive to build and should be adequate for a small system like that proposed for Elfin Cove. 15 The transmission line is another example of "low-tech" design. The design assumed that the line would lie on the ground, through the trees. Thus, there is no clearing costs and the line was priced in 500-foot spools which are heavy but light enough to be moved by people, three-wheelers, sled with winch, etc. As a result, the transmission line is much less expensive than it would be using standard construction techniques. There is, of course, a trade-off involved. Standard construction requires less mainte- nance and is somewhat more reliable,. but this extra value carries a larger price tag. The cost estimates assume the maximum use of local labor. The important saving comes from not providing a-construction camp, and in avoiding expensive mobilization, de-mobilization, and transpor- tation expenses. Because the time commitment for this project would be longer than for typical public works projects in Elfin Cove, wages would have to be sufficient to get some residents to forego other income opportunities, ones that might usually be necessary to maintain their annual income. We assumed local labor is paid approximately $20 per hour including benefits (after taking out taxes and benefits, take-home pay would be less). For specialized skills (electrician, etc.), we assumed union-scale wages and per diem. The equipment cost is for new equipment. It may be possible to find useable used equipment which is less expensive but adequate for the job (used penstock material, for example), but it is not a good idea to count on finding such material. 16 In summary, the estimates provided represent close to the minimum cost “or a reliable system. It is entirely possible that further, more detailed design investigations will rule out some of the low-cost techniques and raise the system cost somewhat. It is also possible to contract for an entirely different, more expen- sive design/construction approach. Finally, detailed review plus revision of elevation and distance measurements might possibly reduce the cost somewhat. At this reconnaissance level of design it is not possible to provide final estimates. This report provides a reasonable guide for community planning, but readers should be aware that these are local resources, local labor, low-tech cost estimates and use them appropriately. Construction Cost Estimate The proposed Crooked Creek hydro system has four parts: (1) div- ersion of Upper Crooked Creek into Jim's Lake, (2) the hydropower system using Jim's Lake, (3) the transmission line from -the powerhouse on Port Althorp to Elfin Cove, and (4) the distribution system within Elfin Cove (see Figure 4). The design and cost of each part is described below. The designs provide a workable basis for planning and for estimating costs. However, other equally good designs could also be developed. DIVERSION OF UPPER CROOKED CREEK As noted earlier, Jim's Lake watershed does not contain enough water to provide reliable power for Elfin Cove. A complete system would require the streamflow of Crooked Creek and the storage of Jim's Lake. Diversion of Crooked Creek requires a diversion dam, intake valve or sluice-gate, flume or penstock, and tailrace. 17 Figure 4 ELFIN COVE CROOKED CREEK [ JIM'S LAKE HYDROELECTRIC SYSTEM Approximate location ve GREEK 6 ¢ Sy Fe cane ae nenceratien =O WE WY POWER HOUSE & SKS WS We LE ENG \ ~ Approsmote Diversion Dam. The dam need only be large enough to divert most of the flow into the flume/penstock -- three to five feet high would almost certainly be sufficient. It should be built at any convenient location just far enough upstream to provide a downhill gradient for the flume/penstock. Due to the relative inacces- sibility of the location, it is assumed that the dam would be made completely of local materials: wood, rock, and earth. Therefore, cost estimates include only labor, plus an allowance for hand held equipment (chainsaws, etc.). During the site visit, potential sites were found at approximately the 500 foot level. Other sites are probably available. Construction of the diversion dam is expected to take approximately 80 manhours (for example, 2 men, one week). : = Materials: $0 (Local materials only) Labor: 80 hours Flume/Penstock. Because power is not being generated in this portion of the system, head loss is unimportant. Thefefore, expensive low-friction pipe is not necessary: wood, corrugated metal, an open channel, or most any sturdy material can be used. The cost estimate assumed aluminum corrugated pipe which is slightly more expensive than other corrugated metals but signif- icantly lighter (weight is approximately 77 lbs. per 20 foot section). Weight is a consideration in determining how material is moved and the hours of labor required to move it. The pipe or channel need not extend to the lake, just to a location where the water will drain there naturally. “For this cost estimate, the diversion pipe was assumed to continue to the lake in order to avoid erosion problems associated with dumping high velocity flows onto muskeg. The total distance is approximately 1,650 feet from an appropriate location on Upper Crooked Creek to the lake. (Estimated distance is actually 1,180 ft. plus a 40% allowance for 19 measurement error and non-straight alignment.) Because the pipe must be large enough to capture a good portion of the spring flows, an 18 inch diameter was assumed. The pipe could be staged in a few locations by helicopter. Routing, joining, and tying down the pipe will require approximately two manhours per section. Materials: 1650 ft. @ $9/ft. = $14,850 Labor: 165 hours Intake Valve and Trashrack. A sluice-gate or intake valve at the upper end of the penstock is needed to shut the water off when working on the penstock. There must also be a trashrack or screen to keep floating logs and large debris out of the pipe. The trashrack does not need to be fine enough:to stop leaves, dirt, etc. which would pass through the pipe. The trashrack could be made out of welded re-bar, treated wood, or any other rot- resistant material. Both the trashrack and sluice-gate could be pre-made in Elfin Cove. Installation was estimated at 8 and 16 hours, respectively. Materials: $600.00 Labor: 24 hours JIM'S LAKE TO THE POWERHOUSE A small weir on the lake outlet is desirable to regulate its outflow, but there is no need for a large dam on Jim's Lake. Because the lake is reported to be 24 feet deep, a siphon with the intake sunk 10-12 feet deep would provide the intake set-up. Components of this portion of the power-generation system include a trashrack to screen the intake, a vacuum relief valve, an intake valve, pressure relief plug, an approximately 2,400-foot penstock, the powerplant (turbine and generator), the tailrace, the power- plant shed, and a concrete pad. These are briefly discussed below. 20 Trashrack and Weir. A trashrack is necessary to keep leaves and other debris from clogging the penstock or turbine. It will require periodic cleaning. A weir on the lake outlet, made from local logs, will raise the lake level slightly and regulate its outflow. Materials: $200 Labor: 24 hours Intake Valve. An intake valve is necessary to close down the penstock. Materials: $500.00 Labor: 4 hours Vacuum Relief Valve. If the siphon intake becomes clogged, the weight of the remaining water flowing down the penstock could create vacuum sufficient to collapse the penstock. To prevent this situation, a vacuum relief valve is necessary to allow outside air to enter the pipe to relieve the vacuum. Materials: $100.00 Labor: 2 hours Pressure Relief Valve. Rapid shut-down of the penstock can create significant water-hammer up the pipe. Though pelton-wheel tur- bines are designed to minimize this problem, a blow-out cap or other simple pressure-relief system is necessary to insure that this unlikely occurrence does not destroy the system. Materials: $100.00 Labor: 2 hours Powerplant. Powerplant capacity was assumed to be 80 KW to allow for some community growth and slight transmission/transformer losses. Assuming 350 foot gross head, 330 foot net head, and 65% overall generator-turbine efficiency, a maximum flow of 4.5 CFS was calculated. Cost estimates for a 330 foot net head, 4.5 CFS, 21 80 KW pelton-wheel turbine, and single-phase generator with automatic governor were obtained from various sources. Materials: $76,000 (including $1000 for switchgear) Labor: 224 hours Penstock. Low friction pipe is necessary to minimize head loss. The straight-line distance between Jim's Lake and the inlet is approximately 1,700 feet. A 40% increment was added to allow for measurement error off the air-photo and to allow curves and extra distance in the penstock routing. For cost-estimating purposes, it was assumed that the upper half of the penstock would be required to withstand pressure at the midway point, and the lower half, to withstand pressure at the powerhouse (pressure being static head plus 30% safety allowance for water-hammer). Polyethylene pipe was assumed because it can be flexibly routed around trees, rocks, etc. The pipe can be welded together’at~the tide level using a rented fusion machine designed for that pur- pose. It can probably be winched up to the lake as one long continuous length. That is, the winch could pull the penstock up 20 feet, another section could be fused on, up another 20 feet, and so forth. Because 2400 feet of penstock weighs over 15 tons, the penstock may have to be pulled in three or four sections and then fastened with mechanical connections, but one continuous pull might be possible. Installing the penstock will also require some clearing of trees and rocks, and fastening with rockbolts, cable, etc. Cost estimates were made for 1,200 feet of 125 psi pipe, and 1,200 feet of 200 psi pipe. To accommodate 4.5 CFS at minimum head-loss, 12 inch diameter was assumed. (At this diameter, 4.5 CFS has a total head loss of approximately 19 feet.) Materials: 2400 feet @ $11.25/ft. = $27,000 Labor: 1200 hours 22 Concrete Pad, Shed, and Tailrace. The powerplant requires an enclosure and a concrete pad. A tailrace is also needed to expel the water without significant erosion. One hundred feet of corru- gated aluminum pipe for the tailrace is also necessary. Materials: $4900.00 Labor: 197 hours TRANSMISSION The transmission system was priced as a single-phase, 15 KV #2 XLP concentric neutral cable. Straight-line distance from the outlet of Jim's Lake Creek (the approximate powerhouse site) to the south end of Elfin Cove is approximately 4,800 feet; which, adding 40% for measurement error and non-straight alignment, comes to 6,700 feet. Transmission voltage was assumed to be 7200 volts. Because of the exposed bedrock, shallow soils, and lack of ‘accéss, it would be difficult to bury the cable; thus, it was assumed to be encased in a casing (corflo or some material) on top of the ground. Construction would occur in 500-foot sections from spools staged by helicopter. (500-foot spools are light enough to be managed by hand.) A splice cabinet would be required every 500 feet. Materials include 6700 ft. of primary cable, 6700 ft. of corflo, one 75 KVA transformer (for the powerhouse location), 13 splice cabinets, 13 ground rods, 26 high voltage elbows, and 26 high voltage splices. DISTRIBUTION A possible distribution system design is shown in Figure 5. Primary distribution would be by the concentric neutral cable cited in the transmission section with secondary lines running directly from various transformers to the individual buildings and 23 via distribution pedestals. Prices do not include dock lights, dock power, street lights, or any wiring inside the houses. Prices do include bringing the power to each house including the meter, ground rod, and main breaker outside each house. It was assumed that the cable would be buried (or lie on the ground) or be fastened under the boardwalk with periodic ground connections. The amount and cost of materials and labor is shown in the cost summary. 24 A 7 TRANSMISSION LINE \ [> FROM POWER HovSE BOARD WALK ner eee PRIMARY CABLE ------- SECONDARY CAPLE os TRANSFORMER = PEQESTAL IN) BUILDING Figure 5 ELFIN COVE a FROM AIRPHOTOS TAKEN ©/1/ 82. — ° too’ 200’ 300" boo’ (SCALE VARIES OVER MAP) Cost Totals Specifications Peak Power: 80 KW (to allow for some community growth) Gross Head: 350 feet Net Head: 330 feet Distance: Crooked Creek to Jim's Lake: 1,650 feet (straight-line distance of 1,180 feet plus 40% to allow for non- straight routing and measurement error) Distance: Jim's Lake outlet to powerhouse: 2,400 feet (1,700 feet plus 40%) Distance: Powerhouse to Elfin Cove: 6,70@ feet (4,800 feet plus 40%) Transmission: 7,200 volts using 15 KV #2XLP concentric neutral cable on the ground protected in a corflo utilidor. The costs in Table 5 include the cost of building the hydropower facilities, laying the transmission line, and installing the dis- tribution system in the Elfin Cove townsite. They include the service drop to each house, and the meter and ground rod for each house. They also include the necessary freight, equipment rental, helicopter time, etc. They do not include street lights, dock power, or any wiring inside the houses. They do not include the cost of stream gaging and surveying. For cost purposes, local labor was priced at $20/hour including benefits (for a foreman slightly more, for the remainder slightly less). 26 tab 5 RECONNAISSANCE LEVEL hb tiealtbeas Date March 1 Sn lof 6 fa ____ CONSTRUCTION COST ESTIMATE 4, 1984 | PROJECT _ Elfin Cove Small Hydro ( covea) $C) CODE C| Orawing No | LOCATION peeeees CJ) coves [(() CODED] Estimatorp | Wil TianfsChecker LABOR TOTAL FREIGHT QUANTITY MATERIAL No. Units | Unit Rate Cost Mat'l & Labor ‘DIVERSION - CROOKED CREEK TO JIM' LAKE 5' Diversion Dam Intake Valve (Sluice Gate) Trash Rack Penstock - 18" CMP (Alum. ) 1650 JIM'S LAKE TO POWERHOUSE Trashrack and Weir Vacuum Relief Valve 100 | Intake Valve 12' 500 - Page Subtotal $16,250 * 299 NPA FORM 23(Rev.) Jan. 1980 Page 27 vabie 53 (Coitinueu) Invitation No RECONNAISSANCE LEVEL \ ' / ; CONSTRUCTION COST ESTIMATE \ | PROJECT Elfin Cove ‘Smal Hydro j LOCATION Date March 14, (J covea (CJ) CODE C} Orawing No yeaa |> 2o1_6 (CJ) copes [_) CODED Estimatore wit tiamd Checker QUANTITY MATERIAL LABOR 1 No. Units poo — ‘JIM'S LAKE TO POWERHOUSE continue Cost TOTAL FREIGHT Mat! & Labor | Unit 1° _ Pressure Relief Plug a 1 — | ___Penstock 12" Q (Polyethylene) 2400 : Turbine-Generator-Governor 1 = (330Ft-Net Head, 80KW) | Switchgear 1 | Shed (10' x 12') 1 __Concrete Pad (10' x 12' x 1') 1 Tailrace - 18" CMP (Alum.) 100 b Page Subtotal $108 ,000 1623 tiPA FORM 23(Rev) Jan 1980 Dana 72 ‘ab. > 4 tis VY) fo / Invitation No Date i RECONNAISSANCE LEVEL Shy oroteo | _ _ CONSTRUCTION COST ESTIMATE March 14, 1984 1 PROJECT Elfin Cove Small Hydro (J covea = [-) CODE C} Orawing No ' LOCATION - CT coves (CJ CODED] Estimatora 15744 aqqacnecker QUANTITY MATERIAL LABOR TOTAL FREIGHT No Units Cost Matt & Labor | i \ ~~ Corflo 4/0 Secondary -URD TPX #2 Service URD TPX — __Pedistals =e ___Pad Mount Transformer = (75KVA, 120/240 - 7200V 19) Pad Mount Transformer (25KVA, 120/240 - 7200V 19) HV Elbows 15KVA HV Splice 15KVA Page Subtotal $27,934 "890 NPA FORM 23(Rev) Jan 1980 Dada 20 tab 5 4 ti: 1) ; RECONNAISSANCE LEVEL Wwvitetion No —— eee “bot 6. CONSTRUCTION COST ESTIMATE | PROJECT Elfin Cove Small Hydro [CJ cove =) cope C| Drawing No i LOCATION oe ©) coves ([_) CODED Estimatorn williamg Checker QUANTITY MATERIAL LABOR TOTAL FREIGHT gre _ | No Units | Unit Cost Hrs. Rate Cost Mat'l & Labor | ELECTRICAL (continued) _ _ HV ‘Splice Cabinet 13 | Ea. $ 3,250 39 Ground Rod Assembly 70 | Ea. 2} 53 Meter Bases 40 Ea. | 250 10,000 160 Meters 40 Ea. 60 2,400 * 20 : 7 Page Subtotal $16,490 272 ti PA FORM 23(Rev ) Jan 1980 Naan 2 ab. > | ELL. ‘) a a Invitation No Date : 6 | RECONNAISSANCE LEVEL March 14, 1984 |S"! ole | CONSTRUCTION COST ESTIMATE aren Wis 12 | PROJECT Elfin Cove Small Hydro_ (J cove A) =) CODE C] Orawing No LOCATION, oe C) coves’ ([_) CODED Estimatora will iamg Checker | QUANTITY MATERIAL LABOR TOTAL FREIGHT . nit Hrs. otal |. ee ee No. Units | Unit. | Price Cost Hrs. | Rate Cost Mat'l & Labor | — RENTAL a ~ Helicopter (A= Star) ~ | 8. |Hrs.] 700 | $5,600 ~ Fusion Machine (for Penstock) 1 Mo. 2,000 Cement Mixer 1 Mo. 850 _ Misc. (Winches, Survey, etc.) -- Lot 1,000 uw - Page Subtotal $9,450 18 ts PA FORM 23(Rev) Jan 1980 Ram 2 a [ Invitation No. Date RECONNAISSANCE LEVEL March 14, 1984 | ShtG_of # CONSTRUCTION COST ESTIMATE PROJECT Elfin Cove Small Hydro (J covea (7) CODEC Drawing No i aan © coves [] CODED} Estimator R. Will iapGhecker QUANTITY MATERIAL LABOR TOTAL FREIGHT nit Hrs. otal ___ | No. Units | Unit_| Price Cost a1 Hrs. | Rate Cost Mat‘'l & Labor Balance Forward a $178,124 3084 Freight 674 C Lot} 15 10,110 Labor Electrical Journeyman (Includes Per Dfiem) 360 | 45 $16,200 Local 2724 | 20 $54,480 $188 ,234 f | $70,680 | $258,914 Engineering Management Assistance 40,000 Administration (Bookkeeping, Purchase Orflers, Ftc.) 15,000 SUBTOTAL tt $313,914 Contingency @ 25% 78,479 Total $392 ,393 USE $400 ,000 a NPA FORM 23(Rev.) Jan. 1980 Page 32 $400,000 should be used as a rough, local resource, local labor cost estimate. Prices are in 1984 dollars subject to inflation. For use in community planning, Table 6 summarizes costs by system component. Table 6. Construction Cost Summary Hydropower Component Local labor (1,922 hours @ $20/hr. ) $38,440 All other costs 179 ,585 Subtotal 3218025 Contingency 25% 54,574 Hydropower Total Approximately $275,000 Transmission Component Local Tabor (248 hours @ $20/hr. ) $4,960 All other costs 31,065 Subtotal $36,025 Contingency 25% 9 ,006 Transmission Total Approximately 345,000 Distribution Component Local labor (554 hours @ $20/hr. ) $11,080 All other costs 48,511 Subtotal 359,591 Contingency 25% 14,898 Distribution Total Approximately 375,000 All Costs Hydropower $275 ,000 70% Transmission 45 ,000 11% Distribution 75 ,000 19% Total Approximately $400,000 100% In summary, the Crooked Creek/Jim's Lake system should cost approximately $400,000 to generate power and bring it “to the door" of existing houses. Construction will require approximately 2,724 hours of local labor over one summer; a foreman and a five-person crew working twelve 40-hour weeks. 33 Annual Costs and Financing A community's perception of hydroelectric costs are completely dependent on the financial arrangements made to pay for it. If 100% of the construction, operation, and maintenance are funded by a State grant, the electricity appears cheap -- even free. If the financing occurs 100% by loans, then the electricity -- at least initially -- is thought to be very expensive. At this point in the project development process, no decisions have been made to build or even to continue investigation of the project. There have certainly been no decisions made on how to finance it. Therefore, this section outlines a number of differ- ent financing scenarios to illustrate several possible results. The section is intended to give community residents an understand- ing of the range of possible annual costs. Operation, Maintenance, and Administration Costs. Although hydroelectric projects may seem maintenance free, a variety of tasks are required. Someone must periodically clean the trashracks, check the penstocks, check and adjust the turbine- generator, read electric meters, prepare bills, keep records, etc. Although the exact maintenance cost is difficult to predict, Power Authority staff estimates that $10,000 per year might be required. This amount should cover all the miscellaneous periodic tasks and possibly provide a small sinking fund for minor repairs. Financing and Total Annual Costs. The previous chapter estimated the 1984 construction costs of the project at $400,000. Table 7 and Figure 6 show the annual debt service payment required of the community under different financ- ing scenarios. A 30 year, level-payment loan at 10% interest is assumed. 34 Table 7. Loan Amount and Debt Service Requirement Total Cost - $400,000 Percent Paid Percent Paid Loan Amount Annual Debt For By Grant For by Loan Required Service Payment 100% 0% $0.00 $0.00 80% 20% $80 ,000 $8 ,500 60% 40% $160 ,000 $17 ,000 40% 60% $240 ,000 $25 ,500 20% 80% $320 ,000 $34 ,000 0% 100% $400 ,000 $42 ,500 Figure 6. Loan Amount and Debt Service Requirement $50000 $40000 Debt Service $30000 Payment $20000 $10000 $0 ~ 100% 80% 60% 402 20% of Proportion of the $400,000 Project Financed by a Grant 35 The debt service requirement depends on the financing arrangement. It varies from $0.0 to $42,500; the latter amount is probably unacceptable. The first year a hydroelectric facility is built is its most expensive year in real terms. Each year thereafter its cost declines. There are two main reasons for this. Hydro projects are usually built with some amount of unused capacity to allow for community growth. As the annual cost is mostly fixed, the more electricity used, the less the cost per KWH. The second reason involves inflation. A level payment bond or loan requires a fixed payment each year. But with inflation, each year a dollar is “worth less" than the previous year. Thus, in real terms, the cost declines. If peoples' incomes rise with inflation, the burden of their electric bills decline. The Reconnaissance Report makes a projection of total KWH sales for 1983-2002. The three tables below use the financing scenarios shown below to calculate a cost per KWH. To construct the table, we are assuming a 6.5% annual inflation rate and inflated the operation and maintenance (0&M) costs on that basis. Table 8. 100% Grant Financing - 6.5% Inflation Electricity Electricity Cost Cost Service 0&M Total KWH Nominal in 1984 $ Year Payment Payment Payment Sales ¢/ KWH ¢/KWH 1985 $0.00 $10,000 $10,000 75,000 13¢ 12¢ 1988 $0.00 $12,000 $12,000 100 ,000 12¢ 9¢ 1998 $0.00 $22 ,700 $22 ,700 140 ,000 16¢ 7¢ 36 The column labeled “Electricity Cost Nominal ¢/KWH" shows just that - the cost per kilowatt-hour of electricity in that year assuming that the construction cost, inflation and KWH sales estimates are correct. It is the amount of money a consumer would actually pay for one KWH (assuming the assumptions are correct). The column labeled “Electricity Cost in 1984 $" is somewhat unusual. It shows the value of one KWH of electricity in terms of a 1984 dollar. For example, economists will say, “If there is 6% inflation, a dollar this year is worth only 94¢ next year." If next year's dollar is only "worth" 94¢ in today's value, then a KWH of electricity that costs 13¢ is only "worth" approximately 12¢ in today's value. The point of the column is to show that although the number of dollars required may go up year-by-year, the value of those dollars decreases dramatically. For example, if an extremely inexpensive diesel facility were built and pro- duced electricity in 1985 for 13¢/KWH, and if the diesel cost kept pace with inflation, then by 1998, that 13¢/KWH would cost 29.5¢/KWH. Tables 9 and 10 show cost of power estimates for other scenarios. Table 9. 60% Grant Financing - 6.5% Inflation Electricity Electricity Cost Cost Service 0&M Total KWH Nominal in 1984 $ Year Payment Payment Payment Sales ¢/KWH ¢/KWH 1985 $17,000 $10 ,000 $27 ,000 75,000 36¢ 34¢ 1988 $17,000 $12,000 $29 ,000 100 ,000 29¢ 23¢ 1998 $17,000 $22,700 $39,700 140 ,000 28¢ 12¢ 37 Table 10. 20% Grant Financing - 6.5% Inflation Electricity Electricity Cost Cost Service 0&M Total KWH Nominal in 1984 $ Year Payment Payment Payment Sales ¢/KWH ¢/KWH 1985 $34,000 $10,000 $44 ,000 75 ,000 59¢ 55¢ 1988 $34,000 $12,000 $46 ,000 100 ,000 46¢ 36¢ 1998 $34,000 $22 ,700 $56,700 140 ,000 40¢ 17¢ These tables are not predictions. They are based on assumptions about construction cost, electricity sales, financing arrange- ments, and inflation. It is difficult enough to estimate the construction cost without trying to guess at the country's in- flation rate over the next decade. Nevertheless, the tables illustrate the effect of the financing arrangement on the tost of power and the likely trend in cost over time. Summary The operation, maintenance, and administration cost of operating the Crooked Creek/Jim's Lake hydroelectric system is very roughly $10,000 per year in 1984 dollars. If the project were constructed during 1985, the first year's cost of power might be -- very approximately -- close to that shown in Table 11 (assuming 75,000 KWH sales in 1985 and 140,000 KWH sales in 1998). 38 Table 11. Financing Arrangements and Cost/KWH - 6.5% Inflation 1985 1998 Financing Cost/KWH Cost/KWH 100% Grant 13¢ 16¢ 80% Grant 25¢ 22¢ 60% Grant 36¢ 28¢ 40% Grant 48¢ 34¢ 20% Grant 59¢ 40¢ 0% Grant 70¢ 46¢ What's next -- Stream-Gaging and other steps. Stream-Gaging To determine the amount of electricity the Crooked Creek/Jim's Lake system can produce, at least one year of continuous -Stream- gaging records are crucial. These gaging records could then be compared to other stations in the area and a statistical relation- ship could be developed. Thus, a more reliable estimate of the amount of water could be determined. A continuous stage-recording gage should be installed on Crooked Creek in the vicinity of a possible diversion; a second gage should measure the level of Jim's Lake. If a small wood weir were put on the lake outlet, measurements of lake stage could be used to calculate flow of the outlet stream. Other investigations should await the stream-gaging results. The stream gaging cost estimate in Table 12 includes the equip- ment, installation, and servicing for two recording gages. It assumes three trips to Elfin Cove by people trained to site and service the gages, and monthly service by a local resident to retrieve that month's data. 39 Table 12. Cost for One Year of Operation of Stream Gage Equipment: $ 6,000 Two recording water level stage recorders including datapod, recorder, transducer, cable, equipment shelter, data storage modules, and module reading equipment. Air Travel and Per Diem: $ 5,000 Three, three-day trips (Anchorage-Elfin Cove) for two people. Servicing the Meters: $ 600 Twelve trips made by local residents @ $50 trip. Salary, Overhead, Miscellaneous Equipment, Report Preparation, etc.: = 000 Total : 215°S00 $20,000 is a low-budget cost estimate. For this price the gage would have to be installed by the Power Authority or by another State agency, such as the Department of Natural Resources, Divi- sion of Geological and Geophysical Surveys (DGGS). A private consulting firm would very likely cost more. Other Steps Besides stream-gaging, other feasibility investigations should precede final design/construction. These include confirming elevation (head), surveying distances and completing preliminary alignment for penstock and transmission routing, and confirming the load forecast. All of these investigations should await preliminary results of the stream-gaging. Application for permits should also precede design and construction. Environmental Effects and Permits. This section contains an extremely brief and preliminary environ- mental assessment, and a list of state and federal permits that are required to construct and operate the Crooked Creek/Jim's Lake 40 System. Applying for the permits will probably not be difficult and would likely be done by the Power Authority or another State agency on behalf of Elfin Cove. There is probably no significant negative environmental impact associated with the proposed hydroelectric development. The major environmental effects are changing the natural flow regime of Crooked Creek and the outlet stream of Jim's Lake. According to local residents and the Alaska Department of Fish and Game's Fisheries Atlas, neither stream is anadromous. Also, Jim's Lake has no resident fish. Thus, the fisheries impact is probably minor. There will be impacts on the riperian habitat of the two streams and Jim's Lake. This change will=probably have a local effect on terrestrial species, but, in total, the environmental effects of the project are probably relatively benign. The number and complexity of the required permits are limited because a preliminary assessment shows the streams to be non- navigable and non-anadromous. Required Federal Permits FERC A Federal Energy Regulatory Commission (FERC) license or exemption is required. An exemption is probably preferred. FERC must act on the application within 120 days or it is granted by default. The contents of the application are given in Section 4.107 of the regulations. Required information includes general background, maps, photos, statistics (KW, head, etc.), plus Exhibit E. Exhibit E “is an environmental report... commensurate with the scope and environmental impact of the construction and operation." (Section 4.107(e)). The application must be complete but not long or overly detailed. It does, however, require “Letters or other documentation showing that the applicant consulted or attempted to consult with each of the relevant fish and wildlife agencies 41 before filing the application, including any terms or conditions of exemption that those agencies have determined are appropri- ate..." (Section 4.107 (e)(3)). Those agencies have 30 days to respond. Special Use Permit A much simpler but generally similar permit is required from the U.S. Forest Service. The permit also requires general descrip- tion, maps, and estimates of environmental impact. There is also a 30-day period for State review. In total, the process takes 60-120 days. The application should be sent to the local Forest Service official in Hoonah. Corps of Engineers, 404 - Permit If the stream is navigable, any material or work requires a 404 Permit. For non-navigable streams, a permit is required only if fill is involved. Since the creek in Elfin Cove is not navigable, a 404 Permit is not required if a log-crib dam is constructéd.° If it is an earth-fill dam, then the permit is required. Information for the Special Use Permit should be sufficient for the 404 Permit (though a little more detail concerning fill might be appropri- ate). Required Permits - State Permits Coastal Zone Management Consistency Determination - Alaska Office of Management and Budget. All actions within the coastal zone require a determination that the action is consistent with the relevant coastal zone policies. A consistency determination is triggered by application for any State or Federal permit within the coastal zone, and a separate application is unnecessary. 42 Water Rights Permit - Department of Natural Resources. This permit requires a form of its own; it is much simpler than the Federal permits listed above. If the dam is less than 10 feet high, with storage of less than 50 acre-feet (as in this case), a Permit to Construct or Modify a Dam is not required and the Water Rights Permit should be issued in 30-60 days (if no agency ob- jects). State - Permit Referral System. The Alaska Department of Environmental Conservation runs a permit referral system. If more than one State permit is necessary, the Department of Environmental Conservation (DEC), will coordinate and "push the paperwork"; thus, only one application is required. If only one permit is required, application is made directly to that agency. However, the State's master permit form should be completed to insure that only one permit is required. The master permit determination should take only minutes. Because only a water rights permit is needed, one fills out the master permit forms but applies directly to the Department of Natural Resources (DNR). DNR will trigger the coastal zone consistency determina- tion. 43 A. Chapter III. A Community Diesel System Costs In discussions with local residents, it became clear that they were particularly interested in potential hydroelectric systems and particularly disinterested in diesel. A discussion of central diesel generation is included not because it is recommended by the Power Authority, but because it provides a good reference to evaluate the costs and benefits of hydro-generated electricity. It is a system which is easily visualized. This chapter provides construction and annual cost estimates <for a central diesel system. Because these estimates are only illustrative, they were made in considerably less detail than other estimates in this report. Estimates are order-of-magnitude, only. Table 13. Diesel Costs Construction Cost: Approximately $100,000 2-50 KW generators, generator building, extra fuel storage tanks, etc. Construction Cost: . Approximately $ 75,000 Distribution System (the same as the distribution system for hydropower) TOTAL CONSTRUCTION COSTS $175 ,000 44 Chapter III. A Community Diesel System B. Annual Operation, Maintenance and Administration: $20,000 Sinking Fund for major overhaul, miscellaneous repairs, periodic maintenance. Part-time operator and billing person. Fuel Cost: ; 15¢/KWH 8 KWH/gallon efficiency; Diesel Fuel @ $1.20/gal. Comparison Between Diesel and Hydropower Electricity Cost The calculations in this section are intended to illustrate the type of cost trends that are likely to be characteristic of diesel and hydropower electric costs. Typically, diesel systems are installed using a legislative appropriation (100% grant financing) and the annual costs are paid for by a per KWH electricity charge. Therefore, the figures in this section assume that financing arrangement. They also assume that the load develops as in the reconnaissance report (75,000 KWH in 1985 growing to 140,000 KWH by 1998). Finally, they assume that the cost of diesel fuel rises only with inflation. This certainly understates the future cost of diesel fuel and diesel electricity, but it probably does not distort the results by enough to change the conclusions. The figures are shown twice: once assuming no inflation, and once assuming 6.5% inflation. (The hydroelectric costs using 6.5% inflation are the same as those shown in Tables 8, 9, and 10.) Table 14 and Figure 7 show that, without inflation, the unit cost of diesel electricity falls, but the unit cost of hydroelectricity falls much more rapidly. What is happening is that as more kilowatt-hours are being sold, the cost per KWH falls. With 6.5% 45 Chapter III. A Community Diesel System inflation, the diesel electricity cost rises rapidly but the hydroelectric cost falls. Diesel electricity production includes Many costs that rise with inflation. In fact, fuel costs have often outpaced inflation in the last decade. Hydroelectric costs are mostly fixed. When inflation raises most costs, hydro- electricity rises only slowly (or with expanding electric sales, the cost per KWH actually falls). Table 14. Diesel vs. Hydroelectric Costs 0% Inflation Hydroelectric-Cost ($/KWH) Assuming: Diesel Electric 100% 60% 20% Year Cost/KWH Grant Financing Grant Financing Grant Financing 1985 42 513 36 59 1988 35 -10 oe ~ 44 1998 29 .07 19 sol. 6.5% Inflation Hydroelectric Cost ($/KWH) Assuming: Diesel Electric 100% 60% 20% Year Cost/KWH Grant Financing Grant Financing Grant Financing 1985 42 a3 36 59 1988 42 ae .29 46 1998 -66 16 .28 -40 46 Electricity Price (S/KWH) Figure 7. Diesel and Hydroelectric Costs 08 _INFLATICN hy ""*++.5. oteser HYORO - 20% GRANT $0.30] ~~. Bee Cos wo emer ree rs nee Tt ee ecce cerry ~~. am ee HYORO - 60% GRANT WESeeRer===""Sscqnesesesspecs « HYORO - 100% GRANT $ .00 see et eee et ee el ee ety 1985 1990 1995 2000 YEAR $0.80 6.5% INFLATION 1985 1990 1995 2000 47 Figure 8 ELFIN COVE — WATERSHEDS LEGEND —————— Watershed Boundary 2 ice! sore 1 ee es Sco wm feet Chapter IV. Other Potential Hydropower Sites There are a number of streams near Elfin Cove. This section briefly evaluates their hydropower potential. A map of the larger streams and watersheds near Elfin Cove is shown in Figure 8. A list of the approx- imate area of their watersheds is in Table 15. Table 15. Watershed Areas - Streams near Elfin Cove Watershed Lake Surface (Jim's Lake) Jim's Lake Watershed Upper Crooked Creek Upper Crooked Creek + Jim's Lake Watershed Lower Crooked Creek Joe's Creek Roy's Creek (above waterfall) Ernie's Creek Approximate Area Acres Square Miles 4 0.006 60 0.09 300 0.46 360 0.55 80 0.13 170 0.27 300 0.46 60 0.09 Chapter IV. Other Potential Hydropower Sites A. Roy's Creek The consultant's Reconnaissance Report recommended a micro-hydro facility on Roy's Creek. After a community visit and some delib- eration, Power Authority staff came to different conclusions. According to the consultant's analysis, "The creek is a very smal] one, with flows on the order of only 1 to 3 cubic feet per second (cfs) being the norm. Nevertheless, this flow is adequate to generate 20 to 40 KW which should easily accommodate the village's needs except at times of daily peak demand (breakfast and dinner times) or at times of low water flow conditions."2 A visit to the creek and conversations with local residents in- dicated a number of problems with this assessment. First, the extent of low flow periods is much greater than had been thought. Second, residents described significant flood hazard on the creek and have observed floods large enough to carry large boulders downstream. oe A daily descriptive record of stream stage on Roy's Creek was kept by a local resident. When compared with precipitation records, it shows that Roy's Creek responds very quickly to precipitation or the lack thereof. The record was kept almost continuously from May 15, 1983 through January 8, 1984 and included informal de- scriptions of creek stage -- "creek roaring, creek normal, creek dry," etc. The observations were taken at the boardwalk bridge just above sea level. They show a number of periods when the stream dried up completely and others when the stream was very low. On June 10, the record shows "creek barely running, some pools of water." Between that date and July 18, the creek is dry except for five days when the record shows "creek running very 1. Taken from Reconnaissance Report, p. 58. 50 Chapter IV. Other Potential Hydropower Sites low, some pools of water." There is no record from July 20 through August 6. During that period, the creek may have been dry as there was very little rain, and it was recorded dry on August 7. There were similar periods during the winter when the creek was frozen or very low. These periods included November 19 through December 3 and December 8 through January 1, 1984. The record ends January 8 but residents told us that the creek was frequently dry after that date. Given the frequency with which Roy's Creek runs dry, it appears that without significant storage, a hydro facility could only produce power eight to: ten months during the year and even then the continuity of power could not be predicted with certainty. In flood stage Roy's Creek presents different problems. The creekbed contains large boulders that residents confirm move down the stream at flood stage. These boulders could easily destroy a small log diversion dam. A related problem is the high water during flood stage. After two days of rain (1.75 inch/day), the record shows that the creek was splashing onto the boardwalk which is several feet above the streambed and normal water surface. The gentleman who owns the house and shop at the base of the creek has several times moved out of his house during a storm for fear that the flood would carry his house away. Because of the boulders carried by the stream, the addition of a dam and the very small storage necessary to keep the penstock intake under water might endanger his house and shop. Roy's Creek has no significant storage. Therefore it cannot often meet Elfin Cove's projected peak load. During the frequent low-water periods, the project is unlikely to produce any power at all. Because of these concerns and because of the necessity of protecting the dam from boulders and the additional increment of 51 Chapter IV. Other Potential Hydropower Sites flood hazard a small impoundment would create, the Power Authority does not recommend a hydropower facility on Roy's Creek. Additions to Roy's Creek During informal discussions with the consultants, they mentioned two possible additions to a Roy's Creek system which might improve its performance: fluming Joe's Creek into Roy's Creek to give Roy's Creek more water (thus more power), and diverting Roy's Creek into the lily ponds to add storage. Unfortunately, neither of these proposals would solve the fundamental problems with Roy's Creek. = By running a pipe from Joe's Creek for a distance of approximately 500 feet, water can be diverted to Roy's basin to augment flows. The diversion line would be at the 620 foot elevation. This flow would merge with the south fork of Roy's Creek at elevatidn 550. The south fork merges with the main fork at the 425 feet ele- vation. The diversion would provide more power only when Joe's Creek is running. Unfortunately, Joe's Creek is even more quickly respon- sive to precipitation than is Roy's Creek. Therefore, when Roy's Creek is dry, Joe's Creek is also likely to be dry. In addition, Joe's Creek has an extreme flood stage which moves many large boulders. Careful placement and engineering of the diversion dam would be required. There is no potential storage in Roy's Creek basin. However, the consultant noted the possibility of using two lily _ponds at approximately 850 foot elevation. These lily ponds appear to be in Ernie's Creek drainage. Using them for Roy's Creek would require a diversion on Roy's Creek, approximately a five foot dam on the lily ponds, then rediverting the ponds' outflow back to 52 Chapter IV. Other Potential Hydropower Sites Roy's Creek. But according to local residents, these ponds freeze solid during the winter; therefore, the storage would only be helpful during the summer months. Construction of the system would require two diversion dams but these would have to be constructed above tree-line, a difficult proposition. The commu- nity is currently considering using Ernie's Creek to augment its existing water supply and the diversions would rob Ernie's Creek of some of its source waters. The Power Authority does not recommend using Roy's Creek for hydropower even with either of the two possible additions. Joe's Creek For the reasons noted above, Joe's Creek is not recommended for hydropower. The creek appears to have frequent and extensive low flow periods, the drainage lacks any storage, and the extreme flood storage carries large boulders down the creekbed and makes construction of a dam difficult. Bed movement along Joe's Creek is even greater than on Roy's Creek and flood flows have washed out the footbridge over Joe's Creek on at least one occasion during the last few years. Ernie's Creek Ernie's Creek has a very small watershed (approximately 60 acres). It is not likely to have enough water to generate significant power. In addition, it suffers frequent and extensive low flow periods. However, it is possible that its water would be a useful addition to Elfin Cove's water supply system. 53 Chapter V. Electricity from the Water Supply System When Alaska Power Authority representatives were in Elfin Cove, they discussed the possibility of using the head and flow from the existing water supply system to provide 12-volt power to the new community center, a covered play area, and dock lights. Unfortunately, there does not appear to be enough water available to power such a system and also meet potable water supply needs. This section of the report describes the existing water supply system, make a rough estimate of the power required from the system, and then describes why the system is probably not feasible. The Existing Water Supply System The existing system consists of a three-foot high log-crib impoundment covering a few hundred square feet and containing less than 50,000 gal- lons of storage. It is below a year-round seepage area approximately 120-feet above the high tide level that is (very approximately) 1,500-feet northwest of town. Water flows to town in three 1 1/2-inch diameter plastic pipes (two from the impoundment and one from a 10-gal- lon pail at a spring further up the hillside). Various households tap into the pipes at the townsite. During the winter, taps run continu- ously to avoid water line freeze-up. (Some houses have an overflow valve. In these cases, the tap does not run continuously, but water is continuously spilled below the house.) Water in the impoundment rarely falls below the level of the pipes' intake, and it only flows over the corrugated metal spillway after a period of heavy rain. We were also told that the impoundment needed to be drained and the dam refurbished. During our visit, we saw significant leakage around the base of the impoundment. Power Required from the System Table 16 shows a possible set of power requirements for the system. The calculations are for illustration purposes only. Whatever amount 54 Chapter V. Electricity from the Water Supply System of electricity the system can produce could easily be used, but Table 16 presents some possible figures for consideration. Table 16. Possible Electricity Requirements for the Community Center and Docks Winter KWH/Month Power Requirements Community Building Lights: 10 100-watt bulbs; 4 hrs/day; everyday 120 KWH/Mo Fan: 100-watts; 4hrs/day; everyday 12 KWH/Mo Covered Play Area Lights: 6 100-watt bulbs; 4 hrs/day; every other day = 12_KWH/Mo Subtotal 144 KWH/Mo Dock Lights! Lights: 6 100-watt bulbs; 4 hrs/day; everyday 76 _KWH/Mo Total 220 KWH/Mo Summer Community Building Lights: 10 100-watt bulbs; 3 hrs/day; every other day 45 KWH/Mo Covered Play Area Lights: Rarely Used Subtotal 45 KWH/Mo Dock Lights! Lights: 6 100-watt bulbs; 3 hrs/day; everyday 54 KWH/Mo Total . 99 KWH/Mo Notes: 1. It is not possible to run 12-volt power from the community center to lights on the dock. Even using heavy gage wire, the voltage drop is too great. Dock lights would require 120-volt power. System Feasibility Although there is 120 feet of head available, maintaining existing water pressure requires at least 40 feet of head. If new water lines 55 Chapter V. Electricity from the Water Supply System are to be extended to Roy's cabin and to houses across the Cove, more head is necessary. In any case, there is a maximum of 80 feet of head available. The problem of designing a small in-line turbine that can generate power only when the tap is on at somebody's house is signifi- cant (though during the winter, taps run continuously). Such a system would be small but very complex. The system would be much, much less complex if there were two water lines: one that powered a turbine and then ran into the ocean, and a second that provided water to the town. Unfortunately, it is clear that there is not sufficient water for either system. It is doubtful whether there would be enough water even if Ernie's Creek were flumed to the present water supply location and storage at that location were doubled. In the future, Elfin Cove may need to expand its water system. Demand for water could increase because more houses tap into the system, or because existing households use more water. More water pressure may be needed because the lines service houses further away, because there are more houses, or because household appliances require more préssitre. Both more water and more water pressure could be achieved by improving the system. However, if those improvements occurred and Elfin Cove uses the'extra water and pressure to generate a very small amount of electricity for the community center, then there would be no additional capacity in the water supply system. Summary Given the lack of water and the complexity of the system, generating electricity from the water supply system does not appear to be a feasible project. If Elfin Cove needs additional water and/or water pressure, the following measures are recommended: 56 Chapter V. Electricity from the Water Supply System Additional Water: 1. The current water supply impoundment loses a significant amount of water through and around the wooden dam. If the dam is recon- structed, made tighter, and augmented with a waterproof sheet of some kind, a significant amount of water would be saved. 2. Ernie's Creek could be flumed to the present impoundment site. This would require significant additional storage at the impound- ment. Additional Water Pressure: aa 1. Much of the water pressure is dissipated in friction with the walls of the three small-diameter pipes. If the three were combined into one large diameter pipe (approximately four inches), there would be much greater water pressure in the distribution system. 57 Chapter VI. Wind Elfin Cove residents are interested in making use of the potential energy in the wind. This could be accomplished in three ways: a small wind-electric system to power the community center; a larger generator to supplement community diesel electricity; or a generator to supple- ment the hydropower in the event that Crooked Creek's low flows are inadequate for the town. In the event that a community electric system is developed (either diesel or hydro), a separate, smaller system for the community center would be unnecessary. If a community system is=not developed, a small wind system might be appropriate. Before the system's feasibility can be assessed, systematic wind monitoring must be performed at a well- exposed and potentially high-wind site near the community center. (Wind data taken at sheltered sites in the Cove is not sufficient. ) If a community-wide diesel-electric system is constructed, it would be possible to use a wind generator to augment the system -- to save fuel. It is not economical to use wind generators as the sole source of electricity. With no “outside" source of power, the cost of storing the electricity, cost of maintaining the required AC-frequency, and cost of using sychronous generators would be prohibitive. The diesel- wind system would be more expensive than the proposed small hydro- system. A feasibility assessment requires wind monitoring at an appropriate site near the Cove's proposed distribution system. If the proposed small-hydro system is constructed and if there is insufficient water to provide community needs during prolonged low-flow periods, a wind generator might be appropriate to supplement the hydro. However, the system would probably be very complicated, and it would also probably be expensive to construct a windmill for use only for the one or two months of low flow each year. While wind monitoring (at any site near the potential transmission line route) is appropriate, the 58 Chapter VI. Wind Power Authority recommends that any more detailed investigation of a wind supplement for hydro await the first few years of the hydropower operation. The system is too complicated and is based on too many unproven assumptions to begin planning before the hydro system's operating characteristics are established. Summary If the community is interested in a wind system for the community center, wind monitoring should begin at an exposed site near the center. If the community is interested in a wind system to supplement central diesel generation, wind monitoring should begin at an exposed site near Elfin Cove's proposed distribution system. If the community is interested in a wind system to supplement hydro capacity, detailed feasibility should await the first few years of hydropower operation. Wind monitoring, of course, can occur at any time and its location should be near the Cove's distribution system or near a transmission line route. 59