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Power Creek Hydro Fessability 1992
AMlesKe Energy Auihothiy i Power CREEK feasibility study May 28, 1992 Walter J. Hickel, Govenor Charlie Bussell, Executive Director Prepared for State of Alaska Walter J. Hickel, Governor Alaska Energy Authority Charlie Bussell, Executive Director 701 East Tudor Road P.O. Box 190869 Anchorage, AK 99519 (907) 561-7877 May 15, 1992 Prepared under contract No. 2800467 by: Whitewater Engineering, Corp. 1050 Larrabee Ave. Suite 104-707 Bellingham, WA = 98225 TABLE OF CONTENTS Table: OF Contents. |.....1..c.s.cceoecsassenntsrensssecetusstnensrenosssesuss seveesssruousvenausrsscessses 2 LISE OF FIQUICS sitcccecssseostsccsscasstcscnoeccssavsseressccsessenessssvoucesvuvecesesisensavserstcesesssctsy 4 MISTGE Vales oot... ccsssoncsecousvsccescssacessctsecssseansnssessunocsssesasncessssescauccstsssasceseuensess 4 Executive SUMIMALY ........ cc ceeceeeesseeesseeeeeeeeeeeseeeeeseeeeseeeeeseeeeneseaeeesseeeeeseeeeeseaeees 5 INGFODUCHION ce sccccsscccessesssecnescensstenesacvssencesnecssensuesuvesessssouevencusesevecsrscsusesaucasvoussese 7 Scope Of This Report.........cecscsssessssseesseessessseeessesseeesseesssesseeaseesseees 7 Project History And Other Reports ...........cccccssesssssseesesceeeeseseesseeeeeeeeee 7 Methodology .......sscssscsssesssssssseesessesssseesssseessseeeesseesssseeeesseeeeseneesesseesenses 8 Site Characteristics..........scsssssesssssesessseeesessseessesseesseessessseeesseeeseeseeesseeeeaeess Location HY CrOlOGY......sccsssssccscesssessssseesssssscesssssesseesssscseesessessseeeeesesseeseeeeeeseeessnees BASIN; DESCHI PUN secacectctcsacccctasesnaseedenssssntacenscesceradeseunnsshonanasten Stream Flow Studies . Stream Flow Datasccscisssssessssssssssscctacctecsscecsassesscevesvevecetencvsvetsesters POWER 9CREEK ........ccccccsssesssscceseeceessaceessseeeeseceeesseeeeeseee 16 HUMPBACK, CREEK 2. .scsscscccsssesscosssssesnssocssvsesesvessorsacsnens 17 DOTA senate ceteclechcdchosacorsadesadecnesseserssossctorerosesesssserssennseestsnsnedssasnsnaserassrrassterstesuss 1991 Demand.... Demand Factors .........cssssssssccecccceeeeeeeeeeesssssesscceccencecenecceeeeeeeeeeeeeeeeeeeenes 20 POWER POUCH OM sastecsticcesceascxcserescecescccsecescsasscassenensssoecosacsuccasoatsnasaceuesasaansscere Humpback Creek. POWeOr Cheek... Jcopssesnssoscsessssccccoseosnccactseenscacsesousescsssoaeeesssssseseuesnesessssens Proposed Construction .......cscsscssssssssssscsseseeseessessesessseessessseseeseesaseseesssesessees 31 Diversion Weir / Intake ............::ccssssscsssesssssessssseeseesssesseeeeessessssseeeseees 31 POMStO i sth evatas snsseetetesscescacussneswsccsestusseuseoveoastestssccssserssodsonnzessseuesssbessiees 31 POwWer HOUSE........cccessssssseceeessseeeeeeceeeeeesessceeeecssneeeessccscceaeeesecseceseeeeeeseeas 32 Turbine/Generators .........ccseeseeeseesseeeecesseeesssseeeeseessseeeeesesseseeeeeseseeesenees 32 Transmission Line - Intertic............cccccecssesssssseeesnenscsnsereeeeeeesseneeeeeeeees 32 OVEN AG cbobstaceenlsdete-ceseccsssecsenscrsesenssesssonssssssssaerocssassssecsesatessescens 33 SUDMECISIDIC eis cecsettsccsesssetesccstercesconssssesessenssvenscsvossesesasssscosseseoee 33 UNCerground .......csscssseeeessseeessesesessseeeseseceeesesecessneesseeeseesenensees 33 WHITEWATER ENGINEERING CORP. 2 March 15, 1992 CONStFUICtIOM GOStS crereccerecsrecccrscreseseseccceseesees ee eee ENE Rea een eareateetetaTeteraes 34 EGONMOMIGCIAMALYSIS reccccosceccsccceseseesecesescecscsensscevccerseacececncrcscavessseencectecaversccersees 35 PO EIS avithsccestsrssessscscscetcccsesertscsssersssesscenstresesensencecuratsnnscnstensccrsccererersereees 37 Rate Impact AnalySis ..........ccscssssssssecsseeesseesssseesssseeeeseseesssseeseeseeeeesseeessaeeeenes 39 Mavis Ormen tlerscsererccerescsersccesessccceressscctecescantecatesesccucesceccacescecesecesnsesaccsccareccescees 41 COMCIUSI On eecsccrenessressnesersterssccsnesenscenscctescrescrostinescusseccesressaseeatesesccoscetcontoccesceer 42 BID OQ APY crcscecsscesscescccseccsescerscercectscscsescecssscareccecscctcscssscecsscccencsesucescanscscesweese 43 APPOMN CX trcsscecsecscessvasecscocsasccecsscocscsnscncsecseccszssuecvoceovecrswcsescsversessueveccvveseseswoseesens d4 WHITEWATER ENGINEERING Corp. 3 March 15, 1992 LIST OF FIGURES MaplofAlaskarcccccccsssssscsrosssscecssssenccsseeccssceccseeencetererereertnter ete ttere Maprof Cordova Areducnsccsccssersrscnccccrsrtecececccnucscacecsnasstteeectttete ees Map lof Project Areaicccccccevecenccessesssecescestscesse-stevtecssecescnsscessees Comparison of USGS and ADW Stream Flow Data................ USGS Stream Flow Data, with Average, for Power Creek aa Power Creek Average Daily FIOW..............ccssccsscceeccesccnscesceesceesceuees Power Creek vs. Humpback Cr. Average Daily Flow Comparison.... 18 Cordova Population ieeccscecccscssecccesteccesccecacertonercconeseoncenacneesccsreeeeres 21 re IAT ABN HOV ONAURWNE CEC Production vs. Population ..22 . Humpback Creek Production Capability .. 24 . Power Sold Based on Size of Installation pa . Capability at 2.0 MW vs. Peak Demand........... peceraile . Capability at 2.5 MW vs. Peak Demand........... lo . Capability at 3.0 MW vs. Peak Demand........... ao . Capability at 3.5 MW vs. Peak Demand........... pest oO . Cost per kWh for Various Size Installations ..............ccceeeeeeee esectO 7 Consumer Price INGEXC....s..cccscncoeccoosscocecorescssscccsccssecrscsscocccesscsesess 38 LIST OF TABLES Monthly Demand ‘Conversion HactOrs)cccs-cccssseccsss-ssssccseecssesseceesesss Estimated Annual Power Production for Power Creek Construction Costs for Various Sizing Options.................. Price per kWh at Various Loan Rates and Plant Sizes SON WHITEWATER ENGINEERING Corp. 4 March 15, 1992 EXECUTIVE SUMMARY Introduction: Whitewater Engineering Corp. has completed a study to determine the feasibility of constructing a hydroelectric power plant on Power Creek, and the optimum placement of the associated transmission line to the existing power grid. We have determined that the Project is feasible. The installed capacity of the Project should be 3.0 MW, and the transmission line should be installed underground along Power Creek Road. Site Characteristics: Power Creek is located six miles northeast of Cordova, Alaska in the Chugach Mountains in south-central Alaska. Utilizing 42 years of USGS flow data for Power Creek, we have developed average daily flows for both Humpback Creek and Power Creek at the diversion dam locations. This data will eventually be used to predict an average daily power production for both creeks. Demand: The demand for electricity in Cordova and the surrounding area has shown a steady increase over the history of Cordova's power production. We have developed an average daily demand based on historical data and fit curves to this data. We feel a straight line trend best reflects the historical data as well as being a conservative estimate for predicting future demand. Power Production: Utilizing the average daily stream flows developed above, we predicted the average daily generation capability of the existing Humpback Creek Project and the proposed Power Creek Project at various sizing options. Using today's current demand, we were able to rule out all sizing options except the 2.0, 2.5 and 3.0 MW capacities. It may be beneficial to Cordova Electric Cooperative if the installed capacity of Power Creek is greater than 3.0 MW, however the price per kWh will be higher. Proposed Construction: The proposed construction is a run-of-the-river project. The diversion dam, power plant and transmission line will be sized to support the maximum capability of the computed stream flow. The penstock and WHITEWATER ENGINEERING CORP. 5 March 15, 1992 turbine/generators will be sized to meet Cordova Electric Cooperative's current demand Project Costs: We developed cost estimates for options from 2.0 to 4.8 MW. The cost of the Project will range from approximately $8 million to $13 million with the cost of the transmission line about $1 million. The cost of construction alone did not single out a particular size plant. Economic Analysis: Given the production capability of Humpback Creek and Power Creek and the current demand, we have computed the power sold by the Power Creek Project. The amount sold (utilized) from Power Creek is reduced by the amount produced by Humpback Creek since its power will be utilized first. Given the cost of construction, the power cost to the consumer for the 2.0, 2.5 and 3.0 MW options will vary by no more than $0.002 per kWh purchased. Based on this and the relative equivalence of the three sizes, we conclude the 3.0 MW installation is the best option. PCE Savings: Based on the 3.0 MW plant size, the predicted demand, a predicted inflation rate and a predicted fuel cost increase, we calculated a first year savings of approximately $136,000. The accumulated savings should reach $1 million in about 6 years. When we did these calculations we attempted to be conservative by using a straight line increase in inflation (fuel price increases are based on inflation) and a straight line increase in demand based on a straight line increase in population. Rate Impact Analysis: The rate to the consumer in Cordova should decrease by approximately 1.7 cents/kWh in the first full year of operation. Every year thereafter, the savings will go up. Conclusion: A 3.0 MW run-of-the-river hydroelectric power plant should be constructed on Power Creek and the transmission line should be installed underground along Power Creek road. The consumer will have cheaper power and the State of Alaska will save in PCE payments. WHITEWATER ENGINEERING CORP. 6 March 15, 1992 INTRODUCTION Scope Of This Report The Alaska Energy Authority contracted with Whitewater Engineering Corp. (WEC), contract number 2800467, to perform a study of the feasibility of constructing a hydroelectric project on Power Creek. The main tasks follow: e Collect all pertinent data available including all past feasibility studies, aerial photos, energy demand, economic data and any other pertinent data. « Meet with the City of Cordova, The Eyak Corporation, and Cordova Electric Cooperative (CEC). e Evaluate the data, including research of alternative project designs and sizing options for current and future needs. ¢« Evaluate the best routing of the intertie between the proposed Power Creek power plant and the existing utility grid. Specifically, identify the best option of: submerge the intertie in Eyak Lake, run the intertie underground in Power Creek Road, or run the intertie overhead. ¢ Prepare cost estimates. ¢ Perform an economic analysis to determine the effect that the proposed Project will have on the State of Alaska's Power Cost Equalization Program, and how it will effect the electric utility and consumers of Cordova, Alaska. ¢ Publish a final report. Project History And Other Reports The construction of a hydroelectric power project on Power Creek has been studied for several years starting at least as far back as 1966 although there are indications of survey activity as far back as 1911. The recommendations have covered both a run of the river [1] and a reservoir[3] project. The conclusions have indicated problems with either type, but the reservoir has the greatest drawbacks due to the geology of the proposed locations.[4] The main drawback to the run of the river project has been the lack of storage and the inconsistency of the generation potential. A run of the river project has been recommended in several reports even with the stated inadequacy of the project.[{2][4][5][6] WHITEWATER ENGINEERING Corp. 7 March 15, 1992 Methodology To determine the feasibility and sizing of a run of the river hydroelectric project on Power Creek several predictions and assumptions must be made. Where we have assumed a figure we present our methodology for computing the figure. Thus, the reader can modify the conclusions based on his modifications of the assumptions. We have relied on historical data and have not attempted to predict future occurrences. For example, we utilize the Cordova Electrical Cooperative (CEC) demand for today as the demand for the foreseeable future to predict the effectiveness of the project. We have analyzed historical records to insure the data used is conservative. We have tried several methods to fit curves to the data and have indicated the method chosen in each case. In some cases, it is impossible to avoid trying to predict the future. For example, to predict future cost of diesel generation, one must predict the cost of fuel. We have tried to be conservative when we approach these type of problems. We have computed an average flow for Power Creek based on historical data. These figures were used to predict power generation capability for both Power Creek and Humpback Creek. Since CEC owns and operates Humpback Creek Hydroelectric Plant, we have assumed that CEC will utilize the Humpback Creek plant to its maximum capability and then utilize the power generated by Power Creek. We have based the economic analysis on this assumption. To determine the optimum size and installed capacity for the project, we have computed the predicted power sold verses the predicted power excess. Maximizing the power sold verses the excess power based on today's demand will determine the maximum efficiency and therefore the best size generation plant for Power Creek. These empirical methods must be tempered with judgment. The final cost to the consumer must be considered as the bottom line. Construction cost estimates are based on current prices with labor at prevailing wages (Davis Bacon ). WHITEWATER ENGINEERING CorP. 8 March 15, 1992 SITE CHARACTERISTICS Location Power Creek is located in the Chugach Mountains along the northern shore of the Gulf of Alaska northeast of the city of Cordova, Alaska and approximately 120 miles east southeast of Anchorage, Alaska, see Figures 1, 2, and 3. The creek originates at the Shephard Glacier about 13 miles northeast of Cordova, and flows southwest through a steep walled valley to Eyak Lake.[7] The intake for the project will be located at the base of Ohman Falls approximately 1.25 miles up stream of the USGS gauging station. A penstock will run down the northwest bank of Power Creek to the powerhouse which will be located approximately 1700 ft. down stream from the gauging station. At this point, the water will then flow back into Power Creek. Hydrology The hydrology of the area is influenced by the Japanese current as it flows through the Gulf of Alaska, and the sharp rise of the mountains to the northwest which contain the largest ice field in North America. Weather patterns are similar to southeastern Alaska and include the possibility of both rain and snow most months of the year. Glacial melting adds to the runoff and therefore stabilizes the flow on the warmer days in the summer. Basin Description From Power Creek's origin at Shephard Glacier, it flows through approximately four to five miles of U-shaped glacial valley approximately 1/4 mile wide. This narrow valley opens up slightly into flatter terrain approximately one mile wide for a run of two to three miles. The creek narrows again and flows around a large fan shaped ridge 300 to 400 feet high just prior to cascading over Ohman Falls. Power Creek drops about 120 ft in a run of approximately 500 ft at the falls. In the remaining 1.5 miles to the gauging station just above Eyak Lake, the creek falls approximately 240 ft. Power Creek has a minimal natural storage capability at Ohman Falls, which is reflected in the flow data presented later in this report.. WHITEWATER ENGINEERING CORP. 9 March 15, 1992 Project Location Figure 1 WHITEWATER ENGINEERING CorP. 10 March 15, 1992 SCALE 1:250000 0 5 10 15 20 25 MILES } 5 0 5 10 15 20 25 KILOMETERS J CONTOUR INTERVAL 200 FEET NATIONAL GEODETIC VERTICAL DATUM OF 1929 WHITEWATER ENGINEERING CORP. 11 March 15, 1992 Figure 2. Detailed Construction Cost Estimate Jul 06, 1993 er ; Fn | ci Acct. No Description Quantity| Unit __| Unit Price | Amount ($) 330 LAND AND LAND RIGHTS Jl Land Rights - Generation Plant 1 | % Sales 0 0 2 USFS Special Use Permit 1 LS 15,000 15,000 3 Surveying 1] Ls 100,000 100,000 4 FERC / USFS Land Use Fees 3 YR 15,000 45,000 Total - Acct. No. 330 160,000 | 331 STRUCTURES AND IMPROVEMENTS il POWERHOUSE 1 Excavation 1,400 CY 75 105,000 2 Concrete Foundation (including reinforcing) 300 CY 1,000 300,000 3 Building Superstructure 1 LS 125,000 125,000 4 HVAC, Plumbing 1 LS 100,000 100,000 S Miscellaneous Metals 1 LS 50,000 50,000 6 Inlet Valves 2 EA 50,000 100,000 Total - Acct. No. 331 780,000 332 RESERVOIRS, DAMS, AND WATERWAYS al, DAM, INTAKE, SPILLWAY wl Dock 0 LS 300,000 0 2 Pipeline and Access Road 10,000 LF 49 486,111 3 Excavation 1,000 Cy 75 75,000 4 Rock Drilling (grout holes and drains) 4,000 LF 50 200,000 5 Grout Curtain 500 CY 100 50,000 6 Concrete Dam 1 LS 450,000 450,000 7 Concrete Intake 1 LS 275,000 275,000 8 Intake Screens, Overflow Gates and Hardware 1 LS 125,000 125,000 2. PENSTOCK | Steel Penstock Material, incl. epoxy coating 8,000 LF 140 1,120,000 2 Installation (Buried) 8,000 LF 90 720,000 3 Supports (concrete) 180} CY 500 90,000 4 Surge Tank 0 LS 300,000 0 D Bifurcation 1 LS 50,000 50,000 6 Couplings 1 LS 80,000 80,000 Total - Acct. No. 332 3,721,111 TURBINES AND GENERATORS Supply (1.5 MW each) 2| EA Instal 2| EA 550,000 125,000 1,100,000 250,000 Total - Acct. No. 333 1,350,000 334 ACCESSORY ELECTRICAL EQUIPMENT Al Switchgear 1 LS 204,000 204,000 2 Controls / Startup 1 LS 90,000 90,000 3 Miscellaneous Electrical 3 LS 100,000 300,000 Total - Acct. No. 334 594,000 335 MISCELLANEOUS MECHANICAL EQUIP al CRANE 1 LS 50,000 PZ) FLYWHEELS 2 EA 120,000 Total - Acct. No. 335 170,000 352 STRUCTURES AND IMPROVEMENTS (TRANSMISSION FACILITY) Al Substation Foundations 1 ES a2, Oil Spill Containment 1 LS 3 Grounding Grid 1 LS Total - Acct. No. 352 353 SUBSTATION EQUIPMENT & STRUCTURES Jl Main Transformers 2 LS py) Accessory Switchgear Equipment 1 LS Total - Acct. No. 353 356 FIXTURES, CONDUCTORS & DEVICES wl Underground Transmission Line (7 Miles) 1 LS 945,000 945,000 2 Electrical Engineering 1 LS 35,000 35,000 Total - Acct. No. 356 980,000 330 331 332 333 334 335 352 353 356 SUMMARY LAND AND LAND RIGHTS STRUCTURES AND IMPROVEMENTS RESERVOIRS, DAMS, AND WATERWAYS TURBINES AND GENERATORS ACCESSORY ELECTRICAL EQUIPMENT MISCELLANEOUS MECHANICAL EQUIP STRUCTURES AND IMPROVEMENTS SUBSTATION EQUIPMENT & STRUCTURES FIXTURES, CONDUCTORS & DEVICES MOBILIZATION (LS) Total Direct Construction Costs Design Engineering FERC and Other Licensing Construction Management Subtotal: Constr, E, L, M Costs Contingency Interest During Construction 1992 ESTIMATED PROJECT COST One Year Debt Service PROJECT COST AND DEBT SERVICE Plant Maximum Output (Installed Capacity) Projected Annual Energy Cost Per Installed kW - 1992 FERC Project Number PP 11243 at at at 7,871,111 160,000 780,000 3,721,111 1,350,000 594,000 170,000 30,000 86,000 980,000 275,000 _ 8,146,111 300,000 200,000 432,000 —_ 9,078,111 20% 1,815,622 12% 1,307,248 12,200,981 0% 610,049 12,811,030 kW = 3,000 kWh/yr= 12,530,000 $/kW = 4,067 Power Creek Hydroelectric Project phology uytes SS WHITEWATER ENGINEERING CORPORATION 1050 LARRABEE AVE. ¢ SUITE 104-707 ¢ BELLINGHAM, WA 98225 PH (206) 733-3008 ¢ FAX (206) 733-3056 Power Creek drainage area above diversion weir and Ohman Falls. Ice bridge immediately above Ohman Falls. Diversion weir location ''A" between ice bridge (shown above) and Ohman Falls (shown below). Diversion weir location ''B" below Ohman Falls. Looking upstream below Ohman Falls. Penstock route on left bank. Example of the many drainages along the penstock route (on opposite bank from the penstock). Looking downstream from the intake and Ohman Falls. Penstock route on the right bank. —-— “at — | (7 OPERATOR'S BUILDINGS. \— |. _INTAKE/ [if oe = So SE DIV. WEIR PENSTOCK— | _-~ | > POWER CREE RHOUSE NBS an oe Wy 2 “) 6 -— ee a Pe ep eet SEE ZS existing POWER CREEK ROAD + ar ; 7 per WELLE: Underground cable AW. 8 _— ay i) gp Yj|AkK |” as Vo Se WIESE AA TT RAR a Lee ae 509 —_ POWER CREEK = Se Ba NS YAK POWER PLANT '\ AND SUBSTATION 27 7 . = | 4 0 1 MILE = i ino ~ Sle i aE cae ; eine) ; Oo | 00 8 i : 1000 0 — 5000 FEET ; iN ws 7 Ee at — CONTOUR INTERVAL 20 METERS : OVERALL PROJECT 2 a UNDERGROUND EXPRESS FEEDER / DOTTED LINES REPRESENT 10-METER CONTOURS 3 SDALASKA FIGURE — e z ae . ; ve NATIONAL GEODECTIC VERTICAL DATUM OF 1929 et A 3 rf n sly aan jo DEPTH CURVES AND SOUNDINGS IN FEET-DATUM IS MEAN LOWER LOW WATER } NY “3 cao = — H SHORELINE SHOWN REPRESENTS THE APPROXIMATE LINE OF MEAN HIGH WATER ‘ 2 A} + te Zo ai ee ! ez THE MEAN RANGE OF TIDE IS APPROXIMATELY 2 METERS Pepe oe WHITEWATER ENGINEERING Corp. 12 reek _ 4 - ——— QUADRANGLE LOCATION Stream Flow Studies We have considered two stream flow studies in establishing the base line flows to be used in computing the average annual production of both Power Creek and Humpback Creek. One study is from the Alaska Division of Water (ADW) and the other from the U.S. Department of Interior - Geological Survey (USGS).[8][9][10] A study by ADW covers the period from May 1989 to September 1991, but the data seems to have several inconsistencies. For example, several consecutive days have the same average flow (June 30, 1989 and July 1, 1989; July 13 and 14, 1989; July 18 and 19, 1989, etc.), there are several gaps in the data (one of approximately seven months), and some of the minimum and maximum flows and their recorded times are difficult to accept. To illustrate this last point, we note December 1 and 2, 1990. The minimum flow for the 1st was recorded as 207.04 CFS which means that at 2400 hours on the 1*t the flow could be no lower than 207.04 CFS. But one minute later at 0001 hours on the 24 the maximum flow was recorded as 87.39 which means that the flow could not have been any higher than that figure. Along with these inconsistencies, the report does indicate that the data should be considered preliminary (the discharge figures are based on only six flow measurements).[10] We have compared the ADW data to the USGS data in Figure 4. The data seems to compare reasonably well except at low flow conditions. We feel the location of the ADW gauge may not have been placed in an optimum location and causes these inconsistent readings at low flow rates. If at some point in the future the data collected by the ADW can be validated, our conclusions may be modified based on the difference in flow rates between the new verified data and the USGS data. The USGS data covers stream flow from 1948 to 1989 at the gauging station which is located approximately 1 1/2 miles downstream of Ohman Falls, and therefore approximately 1 1/4 miles down stream from the projected diversion dam. WHITEWATER ENGINEERING Corp. 13 March 15, 1992 Power Creek Flow Comparison USGS vs ADW 2500 ——— ADW Ave. Flow 2000 USGS Ave. Flow (Scaled by Drainage Area Ratio) 1500 CFS 1000 500 0 5/9/89 6/10/89 7/12/89 8/13/89 9/25/89 10/27/89 11/28/89 12/30/89 May 9, 1989 to December 31, 1989 Figure 4. Comparison of USGS and the ADW Stream Flow Data. The USGS data is scaled to the ADW data based on a ratio of the drainage areas. Stream Flow Data We selected the period from 1980 through 1989 because it is the most recent data and then added in the years 1974 and 1975 since we also have USGS data for Humpback Creek for 1974 and 1975. Given these twelve years of flow data, we developed an average daily flow for Power Creek of 253 CFS and an average annual flow of 183,163 Acre Feet. Based on all available USGS data (1948 to 1989) the average annual flow of Power Creek was 183,786 Acre Feet, see Figure 5. WHITEWATER ENGINEERING Corp. 14 March 15, 1992 { | Yearly vs Average Annual Acre Feet 300000 250000 200000 150000 - 100000 50000 - 0 1948 1958 1968 1978 1988 YEAR ACRE FEET Figure 5. USGS Stream Flow Data, with Average, for Power Creek. Yearly total Acre Feet flow for Power Creek is based on the USGS data for the years 1948 to 1989. The horizontal line is the average of the years pictured at 183,786 Acre Feet. Since the difference between these two figures is less than 1% and the twelve years include the 42 year record high and low annual flow, we feel confident in utilizing the data for the twelve years to develop an average daily flow for Power Creek. WHITEWATER ENGINEERING CORP. LS) March 15, 1992 POWER _ CREEK To compensate for the difference in the location of our projected diversion dam and the location of the USGS gauging station, we utilized the following formula: _p xi FF 24 F; is the stream flow at the intake diversion dam, F, is the stream flow at the USGS gauge, A; is the drainage area above the intake and A, is the drainage area above the gauge. Utilizing this formula and the USGS data as outlined above, we have computed an average daily flow at the proposed diversion dam location, see Figure 6. POWER CREEK Average Daily Flow 1000 CFS 10 Day Moving Average 500 CFS January 1 to December 31 Figure 6. Power Creek Average Daily Flow. The gray area is the daily average flow for Power Creek based on the twelve years of data for 1974, 1975, and 1980 to 1989. The solid line is a 10 day moving average. WHITEWATER ENGINEERING CORP. 16 March 15, 1992 HUMPBACK CREEK To predict the power generation that CEC will utilized from Power Creek, we must first know the power generated at Humpback Creek since we assume the power from Humpback Creek will be utilized before the power from Power Creek. This assumption seems reasonable when one considers the Humpback Creek generation plant is owned by Cordova Electric Cooperative and, at this time, we also assume CEC will not own the Power Creek plant, but will purchase wholesale power from this project. To compute the power generated by Humpback Creek, we must first find appropriate flow data for the creek. The flow data for the years 1974 and 1975 were not used directly for several reasons. First, the setup at Power Creek is permanent and situated in an ideal location whereas the setup at Humpback Creek was temporary and not ideally located. Second, the two available years, 1974 and 1975, are not indicative of the average annual acre feet as shown by Figure 5. In fact, the acre feet for 1974 was a record low. Additionally, the large data base available for Power Creek provides a better base from which to predict an average year. The flow we used for Humpback Creek was based on Power Creek's large data base of historic flow and adjusted to Humpback Creek. Because of the proximity of the two drainage areas, the similar terrain and the similarity of the observed weather patterns, we feel one set of data can be converted to the other. First, a daily ratio was developed based on the USGS flows for Power Creek and Humpback Creek for the only years we have data for both creeks, 1974 and 1975. The flow data for Humpback Creek was generated for the years 1980 to 1989 based on the ratios so developed. Secondly, we scaled each daily result to ensure the total acre feet for the two creeks were in the same ratio as the drainage area ratios. Figure 7 shows the resulting flow data for Humpback Creek compared to the actual average flow of Power Creek. The flows in Figure 7 for Humpback Creek are scaled by the drainage area ratio so a comparison can be made. WHITEWATER ENGINEERING Corp. 17 March 15, 1992 1,000 | 900 + 800 + 700 + 600 + 500 ; 400 ; 300 + 200 100 Average Daily CFS Power Creek vs Humpback Creek Flow Comparison PC Actual CFS Corrected to Intake Location —— HC CFS Scaled to Power Creek January 1 to December 31 Figure 7. Power Creek vs. Humpback Creek Average Daily Flow Comparison. The flow for Humpback Creek has been scaled up for comparison purposes based on the difference in the drainage areas. The slower build up and longer duration of higher flows for Power Creek can be attributed to the long and level valley above Ohman Falls. Humpback Creek has a short and steep drainage area. WHITEWATER ENGINEERING CoRP. 18 March 15, 1992 DEMAND 1991 Demand We have constructed Cordova's daily and peak demand for 1991 based on Cordova Electric Cooperative's 1990 data. For Cordova, 1990 is considered a typical year, and reflects normal operations and consumption of energy for the fish processing plants and other local businesses. We have used this year as a basis for all calculations. The 1991 daily peak and average hourly demand data that is displayed in the accompanying charts is based on Cordova Electric Cooperative's (CEC) 1990 recorded daily demand data and then converted to 1991. To obtain the 1991 data, we adjusted the 1990 daily data by monthly percentages provided by CEC, as follows: Table 1. Monthly Demand Conversion Factors. January 3.7% February 4.7% March 3.7% April 3.3% May 1.9% June no change July 18.3% August 13.3% September 2.9% October 6.7% November 13.2% December 10.0% The resulting total demand for 1991 is equal to the ending actual total recorded by CEC for 1991. We used these computed figures to produce all charts depicting the daily average and peak demands. For each chart, (see Appendix), the average hourly demand is represented by the solid black area and the peak demand is represented by the white area above the black and shown as a line above the black area . WHITEWATER ENGINEERING CoRP. 19 March 15, 1992 Demand Factors The numerous variables that affect the demand do not lend themselves to empirical analysis. We feel we have selected the most conservative approach by utilizing the 1991 demand for all years considered. What follows is a short discussion of those factors we feel could effect the demand expected by CEC. The discussion is meant to illustrate our goal of being conservative, not to try and predict future demand. The major user of power, at least in the summer months, is the fish processing industry. There is currently an uncertainty in the fishing industry and therefore the fish processing industry. However, the historical trend for fish processing in Cordova, is for stability. One plant may close, but another opens. The recent law by the Alaskan Legislature restricting the use of floating fish processors may have a positive effect on the industry in Cordova. At the present time, the outlook seems fairly stable, but is also completely unpredictable. The remainder of the demand is directly related to population. Either the citizens utilize the power, or an increase in population causes an increase in related demand (commercial, industrial, and community power usage). The population has shown a slow but steady growth since records have been kept.[13] We have fit a straight line to the population data and a growth curve as well, see Figure 8. The historical growth seems to follow the straight line and not the growth curve. Therefore, we feel the population growth of the area (the data includes Eyak and the surrounding area of Cordova) can best be estimated by the slower straight line trend. WHITEWATER ENGINEERING CoRP. 20 March 15, 1992 | City of Cordova Population Estimate 4000 3500 Zz. 3000 = 2500 = c 2000 ee —- => 59 ° Historic Population 5 1500 | Straight Line Growth | Px 1000 | —= = = 1.48% Annual Growth 500 | | ——= == Level (no growth) o 4 | 1960 1970 1980 1990 2000 2010 2020 YEAR Figure 8. Cordova Population. Cordova's historical population is indicated by the circles and is taken from U.S. census figures for 1960, 1970, 1980 and 1990. The period from 1981 to 1989 were other studies and are not as reliable because the methods of counting changed during that period. Years where the data was not available are interpolated from the surrounding data. A growth curve was fit to the data (the upper dot-dash line) which represents a 1.48% annual growth rate. A straight line was also fit to the data (the middle straight line). A no growth line is displayed for the currently accepted population of 2550. When we compute the future amount of energy sold from Power Creek, we assume a Straight line growth. The straight line growth is conservative and predicts an average growth rate over the next 30 years of about 1% per year. As shown in Figure 8, Cordova has grown at this rate for the past 30 years. WHITEWATER ENGINEERING CoRP. 21 March 15, 1992 The last factor effecting the amount of demand is the per capita usage of power by the population. For example, the population served by CEC has remained fairly stable from 1984 through 1989, but the actual power generated has increased from approximately 19 million kWh in 1985 to 21 million kWh in 1989.{11][12] This trend is typical in most communities as the result of the increased appliance availability and usage, and the convenience of using electric power. The trend for Cordova is illustrated in Figure 9. CEC Population vs Production 2900 + + 24500000 2 2700 22500000 = aT + 20500000 2300 Ss + 18500000 &, 2100 + ~ —x— i + 16500000 Aa 1900 + x— Population 1700 + —— kWH Generated |7 14500000 1500 + + 12500000 1985 1986 1987 1988 1989 Year Figure 9. CEC Production vs. Population. The population, left scale, is that served by the CEC for the years indicated. The right scale is the energy generated by CEC. Note the level population, but the increasing demand. WHITEWATER ENGINEERING Corp. 22 March 15, 1992 kWH In conclusion, we have utilized the demand for 1991 profiled to a more typical year, 1990 for all calculations. It is hard to predict the future of those factors that effect demand, but the trend seem to be for stability and growth. We have based our revenue predictions on today's demand, resulting in a conservative estimate. We must be cognizant of our decision to assume a straight line growth for demand when it could be a larger increase. The big unknown, which will remain unknown, is the future of the fish processing operation. We can not predict what will happen, but we can assume that if the cost of power decreases in Cordova the processing industry may increase their production and use in their local plants in Cordova. The best guess today is for a status quo in the fishing industry. We must, therefore, consider the possibility of increased demand based solely on the reduction of cost. A cheaper supply should result in an increased demand. WHITEWATER ENGINEERING Corp. 23 March 15, 1992 POWER PRODUCTION Humpback Creek The power produced by Humpback Creek was computed by utilizing the flows described above, but limited to a maximum intake volume based on the size of the penstock and the plant capacity. We utilized the daily average flow, the hydraulic head, and system efficiency to compute an average daily kWh production. The charts in Appendix 3 include the daily production versus the demand and peak demand for 1991. The resulting annual predicted production is 4,102,875 kWh, see Figure 10. We have assumed all of the power produced by Humpback Creek will be utilized by CEC. Humpback Creek, 1.25 MW Estimated Generation 1200 KW/hr 1000 + 10 Day Moving Ave. 800 + 600 + kW / Hr 400 + 200 January | to December 31 Figure 10. Humpback Creek Production Capability. The maximum flow was limited to 128 CFS, based on the observed capability of the Humpback Creek installation. The gray area is the daily total power production resulting in a total annual generation capability of 4,102,875 kWh. The average daily generation is 468 kWh. A ten day moving average is also included. WHITEWATER ENGINEERING Corp. 24 March 15, 1992 Power Creek The power produced by Power Creek was computed using the same method as described above for Humpback Creek. However, we computed the power production for several different size installations. Specifically, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, and 4.8 MW plant sizes were considered and the resulting annual estimated power production (in kWh) recorded. The results are presented in Figure 11 and Table 2. Power Sold vs Capacity 15,000,000 = = 10,000,000 | S — ° on = Smt aS 5,000,000 eo ~ 0 4.8 4 3.5 3 2.5 2 1.5 Capacity in MW ——r—— Power Excess KWh 9 9-1 Power Sold kWh ——°— Power (Sold - Excess) Figure 11. Power Sold Based on Size of Installation. WHITEWATER ENGINEERING Corp. 25 March 15, 1992 Table 2. Estimated Annual Power Production for Power Creek. Installed Capacity ( MW) Power Sold 1000 kWh Power Excess | 1000 kWh Power Total 1000 kWh To determine the appropriate size plant for this installation, we must consider maximizing the production sold while minimizing the excess power generated. Looking at the graph in Figure 11, we see that the production capability utilized and sold begins to level out at 2.5 MW to 3.0 MW and increasing the size beyond that provides very little increase in power sold. From this graph, we can see that the capacity of the power plant should be no larger than 3.0 MW. We have also determined the largest plant possible for the flow is about 4.8 MW. The efficiency of the installation can be estimated by looking at the difference in the power sold and the excess power produced. Figure 11 indicates that the proper size based solely on this criteria would be the 2.0 MW plant. The actual numbers in Table 2 indicate that the 2.0 MW plant should be selected. If one compares the generation capability of the 2.0 MW plant to the peak loads expected, however, there is not enough power to cover the peaks so a diesel generator would be maintained running to cover all peaks. Running a diesel generator defeats one of the reasons for building this Project, namely to turn the diesel generators off during the summer. Figure 12 shows the 2.0 MW plant generation capability versus the peak loads. On the following pages, we have also included the same charts for 2.5 MW, 3.0 MW and 3.5 MW power plants, Figures 13, 14 and 15, respectively. The flat part of the graphs depicting capability indicate the plant capacity has been reached and any increase in flow will not result in an increase in production. After examining the three graphs, we can conclude that WHITEWATER ENGINEERING CORP. 26 March 15, 1992 the 2.0 MW installation will cover only a few of the peak loads, the 2.5 MW plant will cover some of the peak loads and the 3.0 MW plant will cover most of the peak loads in the summer period when the demand is typically at it's highest. Since the limiting factor is the stream flow for production, increasing to 3.5 MW or higher will not provide increased coverage of the peak demand. In other words, the flat part of the graph will move up to 3.5 MW, but the time where the stream flows would support an increase in production, the 3.0 MW installation already covers those peak loads. Again, we conclude based on the current average daily demand and the daily peak demand, that the largest size for the project should be 3.0 MW. The 2.0 MW and possibly the 2.5 MW size are too small to cover the peak loads. Capability vs Peak Demand, 2.0 MW 4000 + 3500 ; 3000 + 2500 2000 + 1500 ; 1000 Peak Demand minus HC kWh 500 + . Power Creek Gen. January 1 to December 31 Figure 12. Capability at 2.0 MW vs. Peak Demand. Generation capability is compared to the peak demand minus the power produced by Humpback Creek. Note the shortfall. WHITEWATER ENGINEERING CorP. 27 March 15, 1992 kWh 8 Power Creek Gen. Peak Demand minus HC January 1 to December 31 Figure 13. Capability at 2.5 MW vs. Peak Demand. Generation capability is compared to the peak demand minus the power produced by Humpback Creek. Note the capability covers some of the peaks, but not all when the generation capability is the highest in the summer months. WHITEWATER ENGINEERING Corp. 28 March 15, 1992 Peak Demand vs Capability 3.0 MW 4,000 + 3,500 + 3,000 ; 2,500 2,000 + 1,500 + 1,000 ; 500 + kWh | Power Creek Gen. Peak Demand minus HC January | to December 31 Figure 14. Capability at 3.0 MW vs. Peak Demand. Generation capability is compared to the peak demand minus the power produced by Humpback Creek. Note the capability covers most of the peaks when the generation capability is the highest in the summer months. WHITEWATER ENGINEERING Corp. 29 March 15, 1992 Peak Demand vs Capability | 3.5 MW 4,000 + 3,500 ; 3,000 ; 2,500 2,000 + 1,500 + 1,000 | ‘ Power Creek Gen. kWh 500 Peak Demand minus HC January 1 to December 31 Figure 15. Capability at 3.5 MW vs. Peak Demand. Generation capability is compared to the peak demand minus the power produced by Humpback Creek. Note the capability covers the same peaks as the 3.0 MW installation. WHITEWATER ENGINEERING CORP. 30 March 15, 1992 PROPOSED CONSTRUCTION The Power Creek Project will be a run-of-the-river hydroelectric power project. This Project does not have a large storage reservoir typical of large dam projects, but rather has a small diversion weir which diverts water from Power Creek into a penstock. The penstock carries the water downhill about one and one-half miles to the power house where the water turns the turbines. Once through the turbines, the water returns to Power Creek. Since Power Creek has the flow capability of producing about 5 MW of power, and Cordova's demand will probably increase, we felt it necessary to construct the intake/diversion weir, powerhouse, and transmission line for 5 MW production capacity. The penstock, turbine/generators, and transformers will be sized for Cordova's current demand and called Phase 1. At some future date when Cordova's demand increases beyond the Phase 1 _ installed capacity, an additional penstock, turbine/generator, and transformer could easily be installed as Phase 2. The following describes this Project (Phase 1) by major task. Diversion Weir / Intake The diversion weir and intake will be constructed of concrete and will be located just below Ohman Falls on Power Creek. The intake will have submerged screens sized to handle 420 CFS (water required for 5 MW) and will be located upstream of the diversion weir. A single penstock will be installed for Phase 1 with a second pipe exiting the intake structure and flanged shut for future penstock installation. The diversion weir will anchor on bedrock on both sides of Power Creek. The spillway will be 50 feet wide to pass a probable 100-year-flood of 5000 cubic feet per second. A steel gate will be located in the spillway that will raise the water level up 8 feet upstream from the diversion weir. This will raise the water high enough to enter the intake structure. During a flood. the steel gate will lower to pass sedimentation and debris that cascade down the canyon. Penstock The penstock will be 8000 feet in length running from the intake structure to the powerhouse. It will be made of steel, welded in place. The penstock will be buried in the access road that runs from the powerhouse to the intake site. The diameter of the penstock will vary depending on the initial installed capacity of the powerhouse. A 2.0 MW capacity will require a 54" diameter penstock. A 3.0 MW capacity will WHITEWATER ENGINEERING Corp. 31 March 15, 1992 require a 66" diameter penstock. The penstock will have epoxy coating on the outside to prevent corrosion. The inside of the penstock will be coated with epoxy to prevent wear due to abrasion from the silty glacial water. Another option is to place two smaller diameter penstocks in place of one larger one. We have looked at this option and have determined that two penstocks are preferable to one larger one. This option should be reviewed in the design phase to verify the current availability and price of the two pipe alternative. At this time we are planning on one larger penstock. Power House The power house will be located approximately 1700 feet downstream from the USGS gauging station on Power Creek. The building will be metal with a concrete foundation and structurally capable of supporting a 10 ton overhead crane. The powerhouse will initially house two turbine/generators and associated switch gear and controls (see Appendix 4 for layout). A third bay will be left vacant for installation of a future turbine. The generators will produce power at 4160 Volts. Each generator will be connected to a separate step-up transformer, increasing the voltage to Cordova's line voltage of 12,470 Volts. After going through the turbines, the water will exit the south side of the building through the tailrace and return to Power Creek. The tailrace will be of sufficient size to prevent scouring. Turbine/Generators There are three types of turbines that will work at Power Creek, given the net head and expected flows. They are a Turgo (impulse), Francis (reaction) and Cross flow. There are advantages and disadvantages to all three types. The most expensive turbine is the Turgo, which costs twice as much as a Francis turbine. The Cross flow turbine costs about 15% less than the Francis turbine. For budget purposes, we used the Francis turbine which is most suited for Power Creek's hydraulic head and flow. Transmission Line - Intertie The 12,470 Volt transmission line will start at the Power Creek Power Plant, step the voltage up from 4160 to 12,470 Volts, connect to the Eyak Substation, and then connect to the Orca Power Plant. Several options exist for transporting the power from Power Creek to the existing power plants in Cordova. WHITEWATER ENGINEERING CoRP. 32 March 15, 1992 Overhead The overhead line will run parallel to the Power Creek road into Cordova. Because of the steep terrain, high wind conditions, higher long term maintenance costs, and the potential visual impact, overhead lines were ruled out. Cordova is currently in the process of replacing their overhead lines with underground. Submersible Submerging the transmission line from the Power Creek power plant to the Eyak Substation is one of the two preferred choices. The cable will be 3 x 4/0, EPR insulation, with 25 pair copper communications wire, all bound in a heavy steel armor. The overall outside diameter of the bundle is approximately 3.5". The cost of the submarine cable including installation is approximately $1,500,000.00. This does not include the connection from the Eyak Substation to the Orca Power Plant, or the step-up transformers at the Power Creek Power Plant. Underground This alternative is the most preferred from the standpoint of installation cost, long term maintenance, and visual impact. The primary conductor will be 3 phase, 3 x 1/O copper with EPR insulation. A 25 pair copper communications cable will also be installed. From the transformers at Power Creek, the line will run underground in Power Creek road, past the city airstrip, south on Chase Avenue to the Eyak Substation, a distance of 6.7 miles. A two mile express feeder would be buried from the Eyak Substation to the Orca Power Plant. This express feeder will allow both the Orca Power Plant and the Power Creek Power Plant to operate from the same substation. (The Eyak Power Plant could possibly be eliminated with the construction of the Power Creek Project.) The cost of the transformers at Power Creek, the 6.7 mile underground cable, and the 2 mile express feeder would be $1,030,000.00. The State of Alaska plans on paving the Copper River Highway from the Orca Power plant to Mile 6 (past the Eyak Substation). The State also has plans to pave the first few miles of the Power Creek Road. The above estimates assume that the cable installation is completed prior to paving the roads. The underground should be included in the State's future paving projects. WHITEWATER ENGINEERING Corp. 3S March 15, 1992 CONSTRUCTION COSTS The construction costs for the above described project is dependent on the size selected. From the previous discussion of comparing the demand with the different size power plants, only the 2.0, 2.5 and 3.0 MW sizes were considered as likely candidates. We have, however, estimated costs of the 4.0 and 4.8 MW installation for comparison. The bottom line estimates are provided in Table 3, and the itemized estimates are included in Appendix 5. The contingency estimate includes such items as a capital reserve fund, a 2.5% bond issue fee, etc. Table 3. Construction Costs for Various Sizing Options. See Appendix 5 for complete details. Site Construction Cost | 8,293,400] 8,774,650] 9,264,750 | 11,684,250 | 13,090,600 Transmission Line Cost | 1,010,000 | 1,030,000 | 1,030,000} 1,055,000] 1,060,000 Total Construction Cost | 9,303,400 | 9,804,650 | 10,294,750 | 12,739,250 | 14,150,600 The price difference for the most likely options is less than 10% and doesn't lead one to a specific conclusion. The 2.0, 2.5, and 3.0 MW options all still appear essentially equally feasible and optimal. WHITEWATER ENGINEERING CorP. 34 March 15, 1992 ECONOMIC ANALYSIS Of the power generated by Power Creek, the amount of energy sold will be the demand minus the power generated by Humpback Creek. Once we know the total energy sold, i.e., demand, and the cost of construction, we can compute the price of the energy to the consumer based on a break-even price. The variable in the equation is loan interest rate. We have provided, in Table 4, the predicted costs to the consumer based on the construction costs, and today's demand as discussed above. The values for the 3.0 MW Plant Size shown below on Table 4 are from Appendix 5-A on page 60-A. Table 4. Price per kWh at Various Loan Rates and Plant Sizes. Loan Interest 10.00% Rate: Once we graph these costs against the plant sizing options we once again note that the difference between the 2.0, 2.5 and 3.0 MW power plant capacities is relatively small, see Figure 16. Given that the capability of the three power plants is relatively the same (based on stream flow and demand), given the construction costs for the three are within 10%, and given the cost to the consumer is within approximately $.002, we conclude the proper sizing for the project is the 3.0 MW. This will also give CEC the most spinning reserve. From our experience with the current demand and operation at CEC, this conclusion seems appropriate. CEC generally has one 2.5 MW generator on line at all times and another 2.5 MW generator on much of the time. Neither of the two generators operate at maximum efficiency when both are on line. Constructing the Power Creek Project with only WHITEWATER ENGINEERING Corp. 35 March 15, 1992 2.5 MW installed capacity is too small given the current demand. A 5.0 MW installed capacity is to large, given the current demand. We recommend sizing the project at 3.0 MW with provision for increasing the installed capacity as the demand increases. If CEC feels the need for additional spinning reserve, then a 3.5 MW installed capacity should be considered. However, a 3.5 MW power project would cost slightly more per kWh. Cost per kWh 0.12 0.1 0.08 0.06 0.04 Dollars 0.02 0 2.0 MW 2.5 MW 3.0 MW 4.0 MW 4.8 MW Plant Capacity Figure 16. Cost per kWh for Various Size Installations at 7% interest. Note the cost per kWh to the customer is almost the same for the 2.0, 2.5, and 3.0 MW projects. — WHITEWATER ENGINEERING Corp. 36 March 15, 1992 PCE SAVINGS To predict the PCE savings to any point in the future, we are forced to predict the growth in demand, and a basic rate of inflation and inflation rate for diesel fuel. Predicting the demand was probably the easier of the two. Given our discussion above about the demand, we assume the demand will follow the population trend and grow at least as fast as the population. Therefore, we have predicted the demand increase by basing it on the current demand (computed 1991) as discussed above, and increasing it the same percentage as the population increase along a straight line. That is, we predict a straight line increase of demand parallel to the straight line increase in population. Because we must need an inflation rate to predict costs (and in particular diesel fuel costs), we have predicted an inflation rate for the next 30 years. We based our prediction on the historical inflation rate as indicated by the Consumer Price Index since 1955, see Figure 17. We then matched a growth curve and a straight line to the data. The growth curve shows the data best fits an annual inflation rate of 4.5%. The straight line shows a trend of about a 2.5 to 3.0% inflation. To maintain our conservative estimates, we utilized the straight line trend. We calculated the fuel inflation at 1.37% above the annual inflation, per AEA. Additionally, we have assumed the transmission line was not included in the cost of construction and therefore the cost per kWh reflects that assumption. In the first full year of production at Power Creek, we calculated a PCE saving of approximately $136,000. The accumulated savings reach $1 million in about 6 years. At that time, the yearly savings exceeds approximately $214,000. Appendix 6 and 7 show the PCE calculations. WHITEWATER ENGINEERING Corp. SMA March 15, 1992 ‘Consumer Price Index | Inflation Estimate 1000 + ; 900 + / 800 + / | ° Consumer Price Index ’ 700 + | Jf 600 . | Straight line 500 + 400 300 200 + 100 g.. 0 f + + + + + + 1953 1963 1973 1983 1993 2003 2013 Figure 17. Consumer Price Index. Utilizing the consumer price index, we computed the historical inflation. We fit the growth curve and straight line to the data to help predict the future inflation. We chose the straight line as the conservative estimate. WHITEWATER ENGINEERING Corp. 38 March 15, 1992 RATE IMPACT ANALYSIS The rate impact to Cordova Electric Cooperative is significant. It is estimated that CEC's current cost of producing power through diesel generation is 13.7 cents per kWh. Assuming a favorable bond rate at 7% interest, Power Creek generation will cost 8.7 cents per kWh. This isa reduction of 5 cents per kWh from the existing diesel generation. However, Power Creek will initially produce only 56% of Cordova's power requirement. How will Power Creek affect the rate to the Cordova consumer? To obtain the rate impact to the consumers, we first have to analyze Cordova's existing rates. CEC's overall rate is based on the total costs divided by the total kWh sold. Power Creek will change a portion of CEC's overall costs. CEC’'s existing costs are broken down into three categories with Power Creek adding a fourth: 1. Overhead Costs 2. Diesel Generation Costs 3. Humpback Creek Generation Costs 4. Power Creek Generation Costs Appendix 6 shows a breakdown of CEC's current generation (Humpback Creek and Diesel generation), yearly demand and costs, along with the estimated PCE payments to the State of Alaska. Appendix 7 shows the same as Appendix 6 with the addition of Power Creek generation, with revised costs and estimated PCE payments to the State. The following further describes Appendix 7. a,b,c,dande, are self explanatory. These items were discussed in previous chapters. A, is the total kWh that CEC generates. This figure increases each year by the population increase, which is approximately 1% per year. B,C andD, are the kWh generated by Diesel, Humpback Creek and Power Creek, respectively. E, is the demand, which increases each year by the population increase. F, is CEC's Overhead costs. These costs should remain fairly level, and will not be affected by Power Creek. Labor should increase due to inflation, however the increase will be offset by the decrease in interest as existing loans for the diesel power plants are paid off. WHITEWATER ENGINEERING CORP. 39 March 15, 1992 G, is the total Diesel generation costs. H, is the Diesel fixed costs which should remain constant and will not be affected by Power Creek. However, with Power Creek on line, CEC should be able to close down and sell the Eyak Power Plant, thus reducing some of it's depreciation. We have lowered the fixed costs by $100,000 per year to reflect this. Iand J, are the Diesel fuel used and associated fuel costs. The fuel usage will dramatically be reduced as the generation by Diesel goes down. The price per gallon of fuel goes up by the fuel inflation rate K, is the costs of power production associated with Diesel generation. These costs will go down as the Diesel generation goes down. The difference in these costs will be transferred over to Humpback Creek and Power Creek, and are included in their costs of production L, is the cost of Humpback Creek generation. Humpback Creek will produce approximately 4,000,000 kWh annually M, is the cost of Power Creek Generation. The rate for power is constant, however as demand increases, the generation usage by Power Creek will also increase. N, is the total generation costs. O, P, Q, R, S, T and U, are self explanatory V5 is the reduced rate in $ / kWh that the Cordova consumers will have. In the first year of Power Creek's operation, the consumer should realize a savings of approximately 1.7 cents per kWh. At the 20 year point in the project, the savings to the consumer should reach approximately 5.6 cents per kWh. It is noted that the above numbers should be reviewed by Cordova Electric Cooperative, Inc. for their accuracy. We feel that Power Creek will have a very positive impact on both CEC and their consumers. CEC's costs should be lowered and stabilized. The most positive aspect of hydropower is not in the immediate rate decrease, but in the long term stable rate that hydropower supplies. WHITEWATER ENGINEERING CORP. 40 March 15, 1992 ENVIRONMENT An environmental impact study was beyond the scope of this report, but some concerns should still be mentioned. There must be a determination as to the impact of diverting the stream flow. Will a minimum stream release be required for anadromous fish? The spawning habitat may not be adversely affected since there are numerous side drainage areas that flow into Power Creek below the proposed intake structure. However, a study of the fish habitat must be performed. A study will have to be performed to determine if there are any cultural resources in the lower Power Creek canyon. There has been a study in the upper stretches of Power Creek in the valley above Ohman Falls. It has been determined that there are historic cultural resources in the upper valley. To our knowledge, there has not been a cultural resource study performed in the Project Boundary area. There are no known cultural resources in the Project area. There are no Section 14 (h)(1) A.N.C.S.A. sites in the Project area. WHITEWATER ENGINEERING Corp. 41 March 15, 1992 CONCLUSION The project is feasible and should be built. The project should be viewed as having two phases. The first phase is what we have described above for construction which will meet the current demand. The second phase should be viewed as adding capacity to cover an increased future demand. The project should constructed with an installed capacity of 3.0 MW. The transmission line should be constructed underground along Power Creek Road. The State of Alaska should consider building the transmission line and must realize there will be a pay back from future PCE savings. The savings to the State will be substantial as well the savings to the consumer. WHITEWATER ENGINEERING CORP. 42 March 15, 1992 BIBLIOGRAPHY 1 10. LE 12% 13. Marks Engineering, 1977 Power Cost Study Supplement _a Hydroelectric Run of River Alternates Power Creek, September 1977 Marks’ Engineering, Electric Distribution System _1977 Construction Work Plan, October 1977 International Engineering Company, Inc., Final Report: Reconnaissance Study of Energy Requirements and Alternatives for Cordova, June 1981. CH2M HILL Engineering of Alaska, Inc., Reconnaissance Study of Hydropower Sites Near Cordova, Alaska, October 1979 Stone & Webster Engineering Corp., Cordova Power Supply Interim Feasibility Assessment, Nov., 1982 Stone & Webster Engineering Corp., Cordova Power Supply Interim Feasibility Assessment, Executive Summary, June, 1982 Stone & Webster Engineering Corp., Cordova Power Supply Feasibility Analysis, Summary Progress Report, March 22, 1982 U.S. Department of Interior - Geological Survey, Humpback Creek Discharge, Water Years 1974 to 1975, June 28, 1991 U.S. Department of Interior - Geological Survey, Power Creek Discharge, Water Years 1948 to 1989, Gauging Station 15216000, June 28, 1991 Alaska Division of Water, Power Creek Preliminary Stream flow Data Summary May 1989 -- September 1991, undated Cordova Electric Cooperative, Inc., Regular Meeting Minutes, October 29, 1990 Mr. Jim Roberts, General Manager, Cordova Electric Cooperative, Inc., interview, February 19, 1992 Alaska Department of Labor, Population for Cordova Alaska Area 1960 - 1990, communication, Feb. 21, 1992 WHITEWATER ENGINEERING Corp. 43 March 15, 1992 APPENDIX leeebower Creek Exceedancemeenncccreseeste ses eeceeenett ecto reeeeceeneeene ee eteeteeT 45 2: USGS Yearly Acre Feet, 1948' to 1989.................-.....00sseesseesreessoes 46 3. Power Creek Generation Capability vs. Demand, for 3.0 MW January 4. Power Creek Power House - Layout 5. Power Creek Construction Cost Estimates............ ccc eceeeseeeeeeeeeeeeee 5-A. Cost of Hydroelectric Power for 3.0 MW Capacity 6. CEG's) Projected Cost without Power Creekie-....---consccocccsseeresssseraes 61 7. CEC's Projected Cost with Power Creek(includes PCE savings) WHITEWATER ENGINEERING Corp. 44 March 15, 1992 Gv "ddOD ONRIGENIONA YaLVMaLIHM C.E.S. - C661 ‘ST Yorke 1000 900 800 700 600 500 200 100 °o iL xIpueddy POWER CREEK 20 30 e 8 8 Rg 80 90 100 Exceedance (% ) WHITEWATER ENGINEERING CORP. OV *duOD ONRIGGNIONG YaLVMaLIHM C661 ‘ST Yoresy Acre Feet :% xIpueddy 300000 - 250000 200000 150000 100000 - 50000 - Yearly Average = 183,786 Acre Feet 1948 1949 1950 POWER CREEK Record High = 275,200 Acre Feet, Record Low = 130,200 Acre Feet ~NOTNONDADGDr AMYTNORNRnDADOFTAMTNOR DOD NNONNONNN NN DH OHDODHDHOHDODORRRERRARRRDODDD DO OO WO WO DAAAMAAAAAAAMAAAAAAAAAAAAAAAAAAAAMAAAAAAAAAAAAAY AD rrrrrrrerrrerere rrrrr rrr rrr ere ere ere ere er er Or re er Oe ere ee YEARLY vs AVERAGE ACRE FEET FROM 1948 to 1989 42 YR. AVG. Ml PER YEAR WHITEWATER ENGINEERING CORP. 2vV :¢ x~pueddy Arenuep KW/ HR 6,000 - 5,500 5,000 4,500 +— 4,000 - 3,500 3,000 -f- 2,500 - 2,000 - 1,500 1,000 500 HUMPBACK CREEK and POWER CREEK Capacity; HC=1.25 MW PC =3.0 MW r NOT HOR DO DOr NM FT MH OO R ODO DO rer rr ere re rer re Ke a 21 22 3 Combined Generation Capability vs Demand, January 1991 LJ Peak Demand MM Average Demand [2 Humpback Creek Gen. Power Creek Gen. WHITEWATER ENGINEERING CORP. Sv :€ xTpueddy Areniq2.J KW /HR 6,000 5,500 5,000 4,500 4,000 3,500 3,000 2,500 2,000 1,500 1,000 500 HUMPBACK CREEK and POWER CREEK Capacity: HC=1.25 MW PC=3.0 MW - nun mom tT HD © Ke OD DM Or nnmet © © KR © DO er er er er er re ere Ke SK A Combined Generation Capability vs Demand, ~ N N N Oo +r YO O FR NN NN ON February 1991 o N LJ Peak Demand MM Average Demand [2 Humpback Creek Gen. Power Creek Gen. WHITEWATER ENGINEERING CORP. 6h :¢ xfpueddy yore KW / HR 5,500 - 5,000 - 4,500 - 4,000 - 3,500 - 3,000 2,500 - 2,000 - 1,500 - 1,000 500 - HUMPBACK CREEK and POWER CREEK Capacity: HC=1.25 MW PC =3.0 MW - wn nwtrtrn Oo rk © DMD OO = r NO TF WO NNN NN — = n mover no re © DD SD rrr rr rere Se A 26 2 2 2 Combined Generation Capability vs Demand, March 1991 Peak Demand MM Average Demand [2 Humpback Creek Gen. Power Creek Gen. WHITEWATER ENGINEERING CORP. os :¢ xfpueddy Indy KW / HR 6,000 5,500 - 5,000 - 4,500 - 4,000 3,500 - 3,000 - 2,500 - 2,000 1,500 - 1,000 HUMPBACK CREEK and POWEK CUKEEK Capacity; HC=1.25 MW PC =3.0 MW 500 -HE r NOT YD Oo Fk ODO HD O _ n Oo tr O© O wR” DO HD Or N SS rr re re rr re ere KF NN Combined Generation Capability vs Demand, April 1991 (J Peak Demand MM Average Demand [2 Humpback Creek Gen. WHITEWATER ENGINEERING CORP. Tg KW /HR :¢ x~pueddy Ae 6,000 5,500 5,000 4,500 4,000 3,500 3,000 2,500 2,000 1,500 1,000 500 HUMPBACK CREEK and POWER CREEK Capacity: HC=1.25 MW PC =3.0 MW - NO TFT DO OR DOD DOK NM TFT MH O KR ODO HD OO Srerrrrreree ff = SN SS KRBS BB NN Combined Generation Capability vs Demand, May 1991 () Peak Demand MM Average Demand 3 Humpback Creek Gen. Power Creek Gen. WHITEWATER ENGINEERING CORP. GS KW / HR € xfpueddy oune 6,000 5,500 5,000 4,500 4,000 3,500 3,000 2,500 2,000 1,500 1,000 500 HUMPBACK CREEK and POWER CREEK Capacity; HC=1.25 MW - unmet no OR © MOF NM FT H Oo KR DO DO = - rere ere ere ea = 22 3 4 5 6 sn © ®D FG oO 21 Combined Generation Capability vs Demand, June 1991 L] Peak Demand MM Average Demand [2 Humpback Creek Gen. Power Creek Gen. WHITEWATER ENGINEERING CORP. es KW /HR € xfpueddy Amp 6,000 5,500 5,000 4,500 4,000 3,500 3,000 2,500 2,000 1,500 1,000 500 HUMPBACK CREEK and POWER CREEK Capacity; HC=1.25 MW PC=3.0 MW rn nr DO Oo rR DDO KFT NM TH O KR ODO HD O nO tft DOD O KR ODO HD FD «| Nn A oO r N Combined Generation Capability vs Demand, July 1991 Power Creek Gen. L] Peak Demand MM Average Demand [2 Humpback Creek Gen. WHITEWATER ENGINEERING CORP. KW /HR € xipuoddy vS ysnsny HUMPBACK CREEK and POWER CREEK 6,000 5,500 HC =1.25 MW PC =3.0 MW 5,000 4,500 4,000 3,500 3,000 2,500 2,000 1,500 1,000 500 - non ntrtr Nn OR DHMHOKT NM TH O KR O OD ere rrerwerrerir = 20 21 2 2 2 2! 2 2 2 2 3 31 Combined Generation Capability vs Demand, August 1991 _] Peak Demand MM Average Demand [2 Humpback Creek Gen. WHITEWATER ENGINEERING CORP. Power Creek Gen. ss KW/HR € xfpueddy Jequieidag 6,000 5,500 5,000 4,500 4,000 3,500 3,000 2,500 2,000 1,500 1,000 500 HUMPBACK CREEK and POWER CREEK Capacity; HC=1.25 MW PC =3.0 MW ran om tT MH OR DM OFT NM FT MH O KR © DO a a a | Nn Oo FT Db OK DBD D N = N NNN NNN ON = Combined Generation Capability vs Demand, September 1991 8 CL) Peak Demand MM Average Demand [2 Humpback Creek Gen. Power Creek Gen. WHITEWATER ENGINEERING CORP. 9g 6,000 5,500 5,000 € xfpueddy HUMPBACK CREEK and POWER CREEK Capacity; HC=1.25 MW PC =3.0 MW r- nO TMH OR DO MDOKFT NM TH OR DDO err ree ere ere ete a r NO FT HD OF DD NNNN NN NN ON Combined Generation Capability vs Demand, October 1991 8 - o C1] Peak Demand MM Average Demand [2 Humpback Creek Gen. Power Creek Gen. 12q0190 WHITEWATER ENGINEERING CORP. zg KW / HR € xtpueddy IsqurlsAoN 6,000 5,500 5,000 4,500 4,000 3,500 3,000 2,500 2,000 1,500 1,000 500 HUMPBACK CREEK and POWER CREEK Capacity; HC=1.25 MW PC=3.0 MW rn Oo tT Oo oO KrF OB HD Oo = no +r YD O KR © rrrrrwrre 19 20 2 25 26 2 2 2 - = Combined Generation Capability vs Demand, November 1991 (] Peak Demand MM Average Demand 3 Humpback Creek Gen. Power Creek Gen. WHITEWATER ENGINEERING CORP. 8s KW /HR © xfpuoddy Jaquisseq 6,000 5,500 5,000 4,500 4,000 3,500 3,000 2,500 2,000 1,500 1,000 500 HUMPBACK CREEK and POWER CREEK Capacity; HC=1.25 MW PC =3.0 MW Hourly Demand and Peak Data Unavailable , - nO tT MH OR DWOMHOrTNM TH O KR DMD HOrAM ere re ee eee Ke HON Combined Generation Capability vs Demand, December 1991 x 5 26 ic 8 9 (] Peak Demand MB Average Demand [3 Humpback Creek Gen. Power Creek Gen. WHITEWATER ENGINEERING CORP. JAMES H. ROBERTS, JR. GENERAL MANAGER Cordova Electric Cooperative, Inc. P. O. BOX 20, CORDOVA, AK 99574 PHONE: 907-424-5555 FAX: 907-424-5527 1050 LARRABEE AVE. SUITE 104-707 BELLINGHAM, WA 98225 PH a 733-3008 FAX (206) 733-3056 THOM A. FISCHER, P.E. President poe Sy | WHITEWATER ENGINEERING CORPORATION : ve | I, | | CB. [ 7 WL] TURBINE 2 | LOAD GOV. ae Gov. | LOAD al MAIN C.B. } | 3 | | TRANSFMR} 4160 V Ls POWER CREEK POWER HOUSE - LAYOUT APPENDIX 4 59 Appendix 5: POWER CREEK CONSTRUCTION COST ESTIMATES Civil Sitework road, (& pipeline trench) 400,000 intake - blasting 125,000 intake - site work 50,000 powerhouse - sitework 100,000 Penstock 8000 If. pipe 600,000 epoxy coating 220,000 couplings 50,000 bends 60,000 thrust blocks 80,000 installation 600,000 Powerhouse building, incl. concrete & shell 435,000 turbine/generators 875,000 flywheels 120,000 switchgear 204,000 misc. powerhouse & elect eqp 85,000 electrical 150,000 mechanical 100,000 start-up 85,000 Mobilization/Cleanup 275,000 Intake Structure concrete diversion dam 450,000 concrete intake structure 275,000 intake screens 50,000 overflow gate & hardware 75,000 Engineering preliminary 100,000 design, survey and permits 300,000 constr design/inspection/mgt 432,000 asbuilt / survey 30,000 Contingency @ 15% 948,900 Construction Interest 1,018,500 ite Construction Cost — 1, ir 8,774,650 9,264,750 450,000 125,000 50,000 100,000 700,000 242,000 70,000 70,000 80,000 690,000 435,000 950,000 120,000 204,000 85,000 150,000 100,000 85,000 275,000 450,000 275,000 50,000 75,000 100,000 300,000 432,000 30,000 003,950 077,700 500,000 125,000 50,000 100,000 780,000 270,000 80,000 80,000 90,000 724,000 435,000 ,100,000 120,000 204,000 85,000 150,000 100,000 85,000 275,000 450,000 275,000 50,000 75,000 100,000 300,000 432,000 30,000 1,059,750 1,140,000 ai Transmission Line Cost 010,000 1,030,000 030,000 _ 550,000 125,000 50,000 100,000 1,200,000 290,000 90,000 90,000 100,000 1,120,000 435,000 1,600,000 180,000 300,000 85,000 220,000 150,000 125,000 275,000 450,000 275,000 50,000 75,000 100,000 300,000 470,000 30,000 1,325,250 1,524,000 600,000 125,000 50,000 100,000 1,400,000 340,000 100,000 100,000 100,000 1,350,000 435,000 2,000,000 180,000 300,000 85,000 220,000 150,000 125,000 275,000 450,000 275,000 50,000 75,000 100,000 300,000 470,000 30,000 1,500,000 1,805,600 684,250 13,090,600 underground cable 945,000 945,000 transformer 4160V - 12,470V 30,000 engineering 35000 50,000 35000 ~ 945,000 50,000 35000 945,000 75,000 35000 5,000 945,000 80,000 35000 al Construction Cost 9,303,400 9,804,650 10,294,750 Whitewater Engineering Corp. 60 2,739,25¢ i 600 May 28, 1992 ISuq JoMoTY A V-09 7661 ‘8Z ARI Construction Cost: Loan Period (years): Interest Rate O & M Fixed Costs: Loan Payment: Administration: O & M Variable Costs: Maintenance: Total Costs: kWHr Sold: Power cost ($/ kWh) Land Lease ($/ kWh) (Preliminary Assumption) $9,264,750 20 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50% $807,743 $840,835 $874,527 $908,800 $943,635 $979,015 $1,014,921 $1,051,333 $50,000 $50,000 $50,000 $50,000 $50,000 $50,000 $50,000 $50,000 $125,000 $125,000 $125,000 $125,000 $125,000 $125,000 $125,000 $125,000 $982,743 $1,015,835 $1,049,527 $1,083,800 $1,118,635 $1,154,015 $1,189,921 $1,226,333 12,530,812 12,530,812 12,530,812 12,530,812 12,530,812 12,530,812 12,530,812 12,530,812 0.078 0.081 0.084 0.086 0.089 0.092 0.095 0.098 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003 Appendix 5-A Appendix 6 PROJECTED COST WITHOU 9 } 994 995 1996 1997 aa Population (Trend): 2550 2584 2615 2645 2675 2706 2736 2766 2797 bb Population Increase %: 0 1.34% 1.18% 1.16% 1.15% 1.14% 1.12% 1.11% 1.10% cc Inflation Trend %: 2.51% 2.45% 2.39% 2.33% 2.28% 2.23% 2.18% 2.13% dd Fuel Inflation %: 3.88% 3.82% 3.76% 3.70% 3.65% 3.60% 3.55% 3.50% ee Fuel Price ($/ gal): 0.90 0.93 0.97 1.01 1.04 1.08 fet2 1.16 1.20 AA Total KWh Generated (AA+ bb*AA): 22,330,858 22,177,675 22,438,279 22,698,882 22,959,486 23,220,090 23,480,694 23,741,298 24,001,901 BB Diesel Generation: 19,820,970 18,177,675 18,438,279 18,698,882 18,959,486 19,220,090 19,480,694 19,741,298 20,001,901 CC Humpback Creek Generation: 2,509,888 4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 DD Power Creek Generation: 0 0 0 0 0 0 0 ) 0 EE Total kWh Sold (EES bbsEE): 20,439,860 20,713,930 20,957,334 21,200,737 21,444,141 21,687,545 21,930,948 22,174,352 22,417,756 FF Overhead Costs: 867,761 900,000 900,000 900,000 900,000 900,000 900,000 900,000 900,000 GG Diesel Gen. Costs (HH+JJ+KK): 2,720,854 2,538,789 2,616,652 2,697,062 2,780,087 2,865,798 2,954,267 3,045,569 3,139,779 HH Fixed Cost: 602,816 600,000 600,000 600,000 600,000 600,000 600,000 600,000 600,000 ll Fuel Used (13.14 kWH/gal): 1,561,819 1,383,555 1,403,391 1,423,226 1,443,061 1,462,897 1,482,732 1,502,567 1,522,403 JJ Fuel Cost: 1,405,637 1,293,481 1,362,093 1,433,251 1,507,025 1,583,484 1,662,702 1,744,753 1,829,711 KK Power Production 712,401 645,307 654,559 663,810 673,062 682,313 691,565 700,816 710,067 LL Humpback Cr Gen Costs (CC*0.080) 200,791 320,000 320,000 320,000 320,000 320,000 320,000 320,000 320,000 @ 0.080/kWh MM _ Power Creek Gen Costs (DD* 0.087) 0 0 0 0 0 0 0 0 0 @ 0.087/kWh NN Total Gen. Costs (FF+GG+LL+MM): 3,789,406 3,758,789 3,836,652 3,917,062 4,000,087 4,085,798 4,174,267 4,265,569 4,359,779 OO Cost $/kWh (NN / EE): 0.1854 0.1815 0.1831 0.1848 0.1865 0.1884 0.1903 0.1924 0.1945 PP PCE Eligible Costs $/ kWh (OO-0.95): 0.0904 0.0865 0.0881 0.0898 0.0915 0.0934 0.0953 0.0974 0.0995 Less $0.095 / kWh QQ _ PCE Payable by AEA $/ kWh(PP*95%): 0.0859 0.0821 0.0837 0.0853 0.0870 0.0887 0.0906 0.0925 0.0945 RR PCE Eligible kWh: 8,453,507 8,566,857 8,667,524 8,768,191 8,868,858 8,969,524 9,070,191 9,170,858 9,271,525 Ss PCE PAYMENTS (QQ * RR): $725,931 $703,671 $725,179 $747,686 $771,222 $795,813 $821,487 $848,274 $876,204 Whitewater Engineering Corp. 61 May 28, 1992 Appendix 6 2827 2857 2888 2918 2949 2979 3009 3040 ... 3192 3343... 3434 1.09% 1.07% 1.06% 1.05% 1.04% 1.03% 1.02% BOAO Nenele 0.96% O'9296) Iyer 0.00% 2.09% 2.05% 2.00% 1.97% 1.93% 1.89% 1.86% ARS22oiiPle| a 1.67% WEO4 Yollierale 1.47% 3.46% 3.42% 3.37% 3.34% 3.30% 3.26% 3.23% 3.19% ... 3.04% ... 229/196) |/enel s 2.84% 1.24 1.29 1.33 ou 1.42 1.47 1.51 Uetsioloic (eS2ie rere ON tele 2.42 24,262,505 24,523,109 24,783,713 25,044,316 25,304,920 25,565,524 25,826,128 26,086,731 27,389,750 285692769 29,474,580 20,262,505 20,523,109 20,783,713 21,044,316 21,304,920 21,565,524 21,826,128 22,086,731 ... 23,389,750 ... 24,692,769 ... 25,474,580 4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 ... 4,000,000 ... 4,000,000 ... 4,000,000 0 0 0 0 0 0 0 Oats Olereke Ojewetel 0 22,661,160 22,904,563 23,147,967 23,391,371 23,634,774 23,878,178 24,121,582 24,364,985 ... 25,582,004 26%7, 99022 27,529,233 900,000 900,000 900,000 900,000 900,000 900,000 900,000 900,000 ... 900,000 900,000 900,000 3,236,974 3,337,234 3,440,639 3,547,273 3,657,220 3,770,567 3,887,401 4,007,815 ... 4,666,868 ... 5,430,165 ... 6,199,888 600,000 600,000 600,000 600,000 600,000 600,000 600,000 600,000 ... 600,000 ... 600,000 ... 600,000 1,542,238 1,562,073 1,581,908 1,601,744 1,621,579 1,641,414 1,661,250 1,681,085 ... 1 780}261) rer. 1,879,438 ... 1,938,944 1,917,655 2,008,663 2,102,818 2,200,200 2,300,896 2,404,991 2,512,574 2,623,736) |=) 6) 3,236,532 ... S195 sto Veil eter 4,695,540 719,319 728,570 737,822 747,073 756,325 765,576 774,828 784,079 ... 830,336 ... 876:593)l// here 904,348 320,000 320,000 320,000 320,000 320,000 320,000 320,000 320,000 ... 320,000 320,000 ... 320,000 0 0 0 0 0 0 0 Ones 0 0 0 4,456,974 4,557,234 4,660,639 4,767,273 4,877,220 4,990,567 5,107,401 SLUG SU Boe 5,886,868 6,650,165 ... 7,419,888 0.1967 0.1990 0.2013 0.2038 0.2064 0.2090 0.2117 ON2146iE ae 0.2301 0.2481 0.2695 0.1017 0.1040 0.1063 0.1088 0.1114 0.1140 0.1167 WEES boo 0.1351 0.1531 0.1745 0.0966 0.0988 0.1010 0.1034 0.1058 0.1083 0.1109 OM TS6iiRr 0.1284 0.1455 0.1658 9,372,191 9,472,858 9,573,525 9,674,192 9,774,859 9,875,525 9,976,192 10,076,859 ... 10,580,193 11,083,527 11,385,527 $905,307 $935,614 $967,157 $999,968 $1,034,082 $1,069,530 $1,106,349 $1,144,575 $1,358,091 $1,612,565 $1,887,734 Whitewater Engineering Corp 62 May 28, 1992 Appendix 7 Cos reek 3.0 oe (1996 a Population (Trend): 2550 2584 2615 2645 2675 2706 2736 2766 2797 b Population Increase %: 0) 1.34% 1.18% 1.16% 1.15% 1.14% 1.12% 1.11% 1.10% c Inflation Trend %: 2.51% 2.45% 2.39% 2.33% 2.28% 2.23% 2.18% 2.13% d Fuel Inflation %: 3.88% 3.82% 3.76% 3.70% 3.65% 3.60% 3.55% 3.50% e Fuel Price ($/ gal): 0.90 0.93 0.97 1.01 1.04 1.08 Aed2) 1.16 1.20 A Total KWh Generated (A + b*A): 22,330,858 22,177,675 22,438,279 22,698,882 22,959,486 23,220,090 23,480,694 23,741,298 24,001,901 B Diesel Generation: 19,820,970 5,646,863 5,777,165 5,907,467 6,037,769 6,168,070 6,298,372 6,428,674 6,558,976 G Humpback Creek Generation: 2,509,888 4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 D Power Creek Generation: 0 12,530,812 12,661,114 12,791,416 12,921,718 13,052,020 13,182,321 13,312,623 13,442,925 E Total kWh Sold (E + b*E): 20,439,860 20,713,930 20,957,334 21,200,737 21,444,141 21,687,545 21,930,948 22,174,352 22,417,756 F Overhead Costs: 867,761 900,000 900,000 900,000 900,000 900,000 900,000 900,000 900,000 G Diesel Generation Costs (H+J+K): 2,720,854 1,102,281 1,131,867 1,162,517 1,194,262 1,227,135 1,261,166 1,296,390 1,332,838 H Fixed Cost: 602,816 500,000 500,000 500,000 500,000 500,000 500,000 500,000 500,000 | Fuel Used (13.14 kWH/gal): 1,561,819 429,799 439,717 449,634 459,552 469,470 479,387 489,305 499,223 4j Fuel Cost: 1,405,637 401,818 426,777 452,802 479,922 508,168 537,574 568,172 599,995 K Power Production 712,401 200,464 205,089 209,715 214,341 218,967 223,592 228,218 232,844 L Humpback Cr. Gen. Costs (C*0.080) 200,791 320,000 320,000 320,000 320,000 320,000 320,000 320,000 320,000 @ 0.080/kWh M Power Creek Gen. Costs (D * 0.087) 0 1,090,181 1,101,517 1,112,853 1,124,189 1,135,526 1,146,862 1,158,198 1,169,534 @ 0.087/kWh N Total Generation Costs (F+G+L+M): 3,789,406 3,412,462 3,453,384 3,495,370 3,538,452 3,582,661 3,628,028 3,674,588 3,722,373 Cost $/ kWh (N/E): 0.1854 0.1647 0.1648 0.1649 0.1650 0.1652 0.1654 0.1657 0.1660 P PCE Eligible Costs $/ kWh (O - 0.95): 0.0904 0.0697 0.0698 0.0699 0.0700 0.0702 0.0704 0.0707 0.0710 Less $0.095 / kWh Q PCE Payable by AEA $/ kWh (P*95%): 0.0859 0.0663 0.0663 0.0664 0.0665 0.0667 0.0669 0.0672 0.0675 R PCE Eligible kWh: 8,453,507 8,566,857 8,667,524 8,768,191 8,868,858 8,969,524 9,070,191 9,170,858 9,271,525 Ss PCE PAYMENTS (Q* R): $725,931 $567,599 $574,592 $582,004 $589,845 $598,130 $606,870 $616,078 $625,767 PCE SAVINGS $ = {(SS-S): $0. $136,072 $150,586 $165,683 $181,377. $197,683 $214,617 $232,197 $250,437_ With Power Creek on Line U Running Total $ : $0 $136,072 $286,659 $452,341 $633,718 $831,401 $1,046,018 $1,278,215 $1,528,652 _ Reduced Costs $/ kWh (OO - O): 0.000 0.017. 0.018 ~~ (0.020 0.022 0.023 0.025 0.027 0.028 Whitewater Engineering Corp. 63 May 28, 1992 ‘ost ek 3.0 006 -CEC'S PROJECTED cost WITH PO} (includes PCE savil Appendix 7 2000 2001 2002 003 004 2007 . 2017 2827 2857 2888 2918 2949 2979 3009 3040 ... 3192 SS43 > 6 3434 1.09% 1.07% 1.06% 1.05% 1.04% 1.03% 1.02% 12.01% oe 0.96% 019296 ane « 0.00% 2.09% 2.05% 2.00% 1.97% 1.93% 1.89% 1.86% 18206 eters 1.67% 105496 cc-e 1.47% 3.46% 3.42% 3.37% 3.34% 3.30% 3.26% 3.23% 319% ee 3.04% 2.91% ... 2.84% 1.24 1.29 1.33 rod 1.42 1.47 aeSil 1.56 1.82 2.10 2.42 24,262,505 24,523,109 24,783,713 25,044,316 25,304,920 25,565,524 25,826,128 26,086,731 27,389,750 28,692,769 ... 29,474,580 6,689,278 6,819,580 6,949,882 7,080,184 7,210,486 7,340,787 7,471,089 7.601239 1) 2100 8,.252'901 a 8,904,410 ... 9,399,482 4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 ... 4,000,000 ... 4,000,000 ... 4,000,000 13,573,227 13,703,529 13,833,831 13,964,133 14,094,435 14,224,736 14,355,038 14,485,340 ... 1S'136'S50 seers 15:788:359) . 3. 16,075,098 22,661,160 22,904,563 23,147,967 23,391,371 23,634,774 23,878,178 24,121,582 24,364,985 25,582,004 26,799,022 ... 27,529,233 900,000 900,000 900,000 900,000 900,000 900,000 900,000 900,000 ... 900,000 900,000 900,000 1,370,546 1,409,550 1,449,884 1,491,585 1,534,693 1,579,244 += 1,625,278 +~—S>- 1,672,837 ... 1,934,964 2,241,796 ... 2,566,218 500,000 500,000 500,000 500,000 500,000 500,000 500,000 500,000 ... 500,000 ... 500,000 ... 500,000 509,140 519,058 528,976 538,893 548,811 558,729 568,646 578,564 ... 628°152) 2 5. 677,740) sie 715,422 633,077 667,454 703,163 740,239 778,720 818,646 860,055 902,987 ... 1,141,986 1;425:690' 5. 3 1,732,537 237,469 242,095 246,721 251,347 255,972 260,598 265,224 269,849 ... 292,978 SOHO /amrerers 333,682 320,000 320,000 320,000 320,000 320,000 320,000 320,000 320,000 ... 320,000 320,000 ... 320,000 4,180,871 1,192,207 «1,203,543 «1,214,880 «1,226,216 + ~—«-1,237,552 «1,248,888 —=«- 1,260,225 1,316,906 1,373,587 ... 1,398,534 3,771,417 3,821,757 3,873,427 3,926,465 3,980,908 4,036,796 4,094,167 4,153,061 4,471,870 4,835,383 5,184,752 0.1664 0.1669 0.1673 0.1679 0.1684 0.1691 0.1697 0.1705 0.1748 0.1804 ... 0.1883 0.0714 0.0719 0.0723 0.0729 0.0734 0.0741 0.0747 0.0755 ... 0.0798 0.0854 ... 0.0933 0.0679 0.0683 0.0687 0.0692 0.0698 0.0704 0.0710 0.0717 ... 0.0758 0.0812 ... 0.0887 9,372,191 9,472,858 9,573,525 9,674,192 9,774,859 9,875,525 9,976,192 10,076,859 10,580,193 11,083,527 11,385,527 $635,952 $646,645 $657,861 $669,614 $681,920 $694,793 $708,249 $722,304 $802,138 $899,536 $1,009,548 $269,356 $288,969 $309,296 $330,354 $352,161 $374,737. $398,100 $422,271 $555,953 ~ $713,029 "$878,186 | $1,798,008 $2,086,977 $2,396,273 $2,726,627 $3,078,789 $3,453,526 $3,851,627 $4,273,898 $6,777,501 $10,018,562 $14,088,035 0,032 0.034 0.036 0.038 0.040 0.042 0.044... 0.055 0.068... 0.084 Whitewater Engineering Corp 64 May 28, 1992