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HomeMy WebLinkAboutNew Stuyahok Wind Feasibility Project Draft Concept Design Report - Jul 2015 - REF Grant 7030006NEW STUYAHOK WIND PROJECT DRAFT CONCEPT DESIGN REPORT Prepared For: Alaska Village Electric Cooperative 4831 Eagle St. Anchorage, AK 99503 Prepared By: Mark Swenson, PE 3335 Arctic Blvd., Ste. 100 Anchorage, AK 99503 Phone:907.564.2120 Fax: 907.564.2122 7/15/15 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report EXECUTIVE SUMMARY This report has been prepared for the Alaska Village Electric Cooperative (AVEC) to provide a conceptual design and cost estimate for the development of a wind power project in the community of New Stuyahok, Alaska. New Stuyahok is a rural, riverine community of approximately 499 residents (2014 U.S. Census Population) located on the north bank of the Nushagak River, 12 miles upriver from Ekwok. A planned intertie project between New Stuyahok and Ekwok is currently in the design phase, and scheduled for construction during the winter of 2016. AVEC currently provides the power to both communities with seperate diesel power plants. Integration of wind power into the electrical power system will offset diesel consumption and provide a renewable energy resource for both rural communities. A Project Layout Plan located in Appendix A shows the project location, and major components of the project. On October 10, 2003, a 30 meter meteorological (met) tower (Met Tower A) was installed in a meadow near the apron of the old airport. This met tower recorded data until June, 7 2005. An additional met tower (Met Tower B) was installed between 2012 and 2014 on the north end of the old airport runway. Because site control for the runway could not be obtained, AVEC has chosen to analyze a potential wind project at the Met Tower A site. The information presented in this report represents 21 months of wind data collected from at the meadow site by Met Tower A. The results of the data acquisition and analysis of the wind resource are included in the New Stuyahok Wind-Diesel Analysis dated July 2015 (Appendix B). The data from the met tower indicated a mean annual wind speed of 5.49 m/s and a mean annual power density of 232 W/m2. The wind-diesel analysis report (Appendix B) describes the wind resource as Class 2 (marginal). Wind turbine options presented within this report are designed to achieve a medium penetration level, with the primary purpose to offset diesel power generation and the secondary purpose to serve the thermal load at the school via a secondary load controller and remote boiler. The analysis within this report also incorporates a future intertie with Ekwok to be constructed by AVEC during winter of 2016. AVEC has selectedthree wind turbine configurations for evaluation. The first configuration includes the installation of (2) Northern Power 100C-24 turbines (NP100-24) near the location of Met Tower A. The NP100C-24 turbine has a hub height of 37 meters (121 feet) and a rotor diameter of 24 meters (79 feet). The turbine is a 95 kW permanent magnet, direct drive generator which produces 3-phase power at 480 V 60Hz. The (2) Northern Power 100C-24 array will have a maximum power generation output of 190 kW. The second turbine configuration includes the addition of a third NP100C-24 turbine near the location of Met Tower A. The (3) Northern Power 100C-24 turbine array will have a maximum power output of 285 kW. The third wind turbine configuration includes one Vestas V-27 turbine near the location 6/5/15 i Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report of Met Tower A. The V-27 turbine has a hub height of 32 meters (105 feet) and a rotor diameter of 27 meters (89 feet). The turbine is pitch-regulated, has a synchronous double- wound (induction) generator, and active yaw control. The turbine has a maximum power output of 225 kW. Table EX-1: Turbine Alternative Comparison Summary Alt Turbine Selection Site Generation Capacity (kW) Estimated Capital Costs per Installed kW Estimated Annual Energy Production @ 100% Availability 1 (2) NP100C-24s Meadow 190 $21,740 647 MWh 2 (3) NP100C-24s Meadow 285 $17,944 928 MWh 3 (1) V27 Meadow 225 $16,114 442 MWh Source: Annual Energy Production Data taken from V3 Energy's July 2015 New Stuyahok Wind Diesel Analysis Table EX-2: Economic Analysis Summary Alt Annual Wind Generation @ 80% Availability (kWh) AVEC Fuel Displaced By Wind Energy (gal/yr) Heating Oil Displaced by Wind Energy (gal/yr) Average Wind Penetration (%) Maximum Instantaneous Penetration (%) Cost/Benefit Ratio 1 517,548 38,054 12 25 131 0.65 2 742,584 53,406 364 36 195 0.74 3 353,591 25,979 12 17 151 0.51 Source: Annual Energy Production Data taken from V3 Energy's July 2015 New Stuyahok Wind Diesel Analysis Based on the analysis presented above, installation of any of the three turbine alternatives considered at the meadow site (near Met Tower A) result in a cost benefit ratio of less than 1. The wind resource at this location was determined to be marginal and the presence of trees and brush creates high wind turbulence for power production. Should AVEC acquire site control for a different property in New Stuyahok with a higher elevation and less surrounding trees and brush, the alternatives presented within this report should be re-examined to indentify the project's viability. If AVEC elects to move forward with the wind project in the meadow site, Alternative 2 provides the most benefit of all the alternatives presented and should be considered the preferred alternative. 6/5/15 ii Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report TABLE OF CONTENTS EXECUTIVE SUMMARY.................................................................................................................i 1.0 INTRODUCTION................................................................................................................1 1.1 CONTACTS..................................................................................................................... 2 1.2 COMMUNITY DESCRIPTION........................................................................................... 2 1.3 EXISTING ELECTRICAL POWER SYSTEMS........................................................................ 2 1.4 ELECTRICAL DEMAND AND EFFICIENCIES ......................................................................4 1.5 PROPOSED COMMUNITY ENERGY PROJECTS.................................................................4 1.5.1 Ekwok - New Stuyahok Intertie .............................................................................. 4 2.0 SITE SELECTION AND CONTROL........................................................................................ 5 2.1 PROPOSED WIND TURBINE SITE.................................................................................... 5 2.2 LAND OWNERSHIP ........................................................................................................ 5 3.0 WIND DATA ACQUISTION AND MODELING ..................................................................... 5 3.1 DATA ACQUISTION ........................................................................................................ 5 3.2 WIND MODELING RESULTS ........................................................................................... 5 4.0 WIND TURBINE SYSTEM ALTERNATIVES.......................................................................... 6 4.1 NEW STUYAHOK WIND TURBINE ANALYSIS ................................................................... 6 4.1.1 Northern Power Systems 100C-24 ......................................................................... 6 4.1.2 Vestas V27 ............................................................................................................. 6 4.2 ALTERNATIVE 1: (2) NORTHERN POWER 100C ARCTIC TURBINES ..................................7 4.3 ALTERNATIVE 2: (3) Northern Power 100C-24 Arctic Turbines ....................................... 7 4.4 ALTERNATIVE 3: (1) Vestas V27.....................................................................................7 5.0 DESIGN AND REQUIRED UPGRADES................................................................................. 7 5.1 REQUIRED POWER PLANT UPGRADES........................................................................... 7 5.2 GRID BRIDGING ENERGY SYSTEM .................................................................................. 7 5.3 ELECTRICAL SYSTEM UPGRADES .................................................................................... 8 5.4 DISTRIBUTION LINE UPGRADES..................................................................................... 8 5.5 GEOTECHNICAL INFORMATION ..................................................................................... 8 5.6 GEOTECHNICAL CONCERNS ........................................................................................... 9 5.6.1 Peat ....................................................................................................................... 9 6/5/15 iii Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report 5.6.2 Frost Heave............................................................................................................9 5.6.3 Permafrost ............................................................................................................. 9 5.6.4 Settlement ........................................................................................................... 10 5.7 DESIGN ALTERNATIVES................................................................................................10 5.8 GEOTECHNICAL INVESTIGATION .................................................................................10 6.0 ECONOMIC EVALUATION ............................................................................................... 11 6.1 METHODOLOGY AND APPROACH................................................................................ 11 6.2 ECONOMIC EVALUATION............................................................................................11 7.0 PREFERRED ALTERNATIVE..............................................................................................12 8.0 ENVIRONMENTAL REQUIREMENTS................................................................................ 12 8.1 WETLANDS AND WATERS OF THE U.S. ........................................................................ 12 8.2 HISTORIC AND ARCHAEOLOGICAL RESOURCES: AHPA ................................................. 13 8.3 FEDERAL AVIATION ADMINISTRATION (FAA)............................................................... 13 8.4 FISH AND WILDLIFE ..................................................................................................... 13 8.4.1 Anadromous Streams ........................................................................................... 13 8.4.2 Migratory Birds .................................................................................................... 14 8.4.3 Threatened and Endangered Species ................................................................... 14 8.4.1 Bald and Golden Eagles ........................................................................................ 15 8.5 NAVIGABLE WATERS ................................................................................................... 15 8.6 FLOODPLAINS ............................................................................................................. 15 8.7 CONTAMINATED SITES, SPILLS, AND UNDERGROUND STORAGE TANKS...................... 15 8.8 STATE REFUGES, SANCTUARIES, CRITICAL HABITAT AREAS, AND NATIONAL WILDLIFE REFUGES ..................................................................................................................... 16 8.9 LAND OWNERSHIP ...................................................................................................... 16 8.10 LOCAL RESOURCES ...................................................................................................... 16 8.11 AIR QUALITY................................................................................................................ 16 8.12 NATIONAL ENVIRONMENTAL POLICY ACT REVIEW...................................................... 17 8.13 ENVIRONMENTAL SUMMARY AND RECOMMENDATIONS ........................................... 17 9.0 CONCLUSIONS AND RECOMMENDATIONS .................................................................... 17 10.0 REFERENCES................................................................................................................... 19 6/5/15 iv Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report FIGURES Figure 1: AEA Wind Resource Map Figure 2: Existing New Stuyahok Power Plant TABLES Table EX-1: Turbine Alternative Comparison Summary Table EX-2: Economic Analysis Summary Table 1.4: Power Cost Equalization Energy Consumption Data FY14 Table 6.2: Economic Evaluation Summary Table 8.4.2: Migratory Birds Located within the Project Area Table 8.13: Environmental Summary Table APPENDICES Appendix A: Wind Project Conceptual Design Drawings Appendix B: V3 Energy’s July 2015 New Stuyahok Wind-Diesel Analysis Report Appendix C: Capital Cost Estimates Appendix D: Environmental Resource Location Map ABBREVIATIONS AAC Alaska Administrative Code ADEC Alaska Department of Environmental Conservation ADF&G Alaska Department of Fish and Game AEA Alaska Energy Authority AHPA Alaska Historic Preservation Act ANILCA Alaska National Interest Lands Conservation Act ANSCA Alaska Native Claims Settlement Act ANTHC Alaska Native Tribal Health Consortium APDES Alaska Pollutant Discharge Elimination System AVEC Alaska Village Electric Cooperative B/C Benefit-to-Cost Ratio BLM Bureau of Land Management CGP Construction General Permit CWA Clean Water Act DOT&PF Alaska Department of Transportation & Public Facilities EA Environmental Assessment ER Environmental Review 6/5/15 v Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report ESA Endangered Species Act FAA Federal Aviation Administration FEMA Federal Emergency Management Agency FY Fiscal Year °F Degrees Fahrenheit HDL Hattenburg Dilley & Linnell IPaC Information Planning and Conservation System ISER Institute for Social and Economic Research kV Kilovolt kW Kilowatt kWh Kilowatt Hour LKSD Lower Kuskokwim School District MBTA Migratory Bird Treaty Act Met Meteorological MWh Megawatt hour NLUR Northern Land Use Research NPS National Park Service NWP Nationwide Permit NWSRS National Wild and Scenic Rivers System OEAAA Obstruction Evaluation/Airport Airspace Analysis OHA Alaska Office of History and Archaeology OHWM Ordinary High Water Mark PCE Power Cost Equalization SCADA Supervisory Control and Data Acquisition SLC Secondary Load Controller SRSD Southwest Region School District REF Renewable Energy Fund RPM Revolutions Per Minute USACE U.S. Army Corps of Engineers USC United States Code USFWS United States Fish & Wildlife Services V Volt WAsP Wind Atlas and Application Program W/m2 Watt per Square Meter Yr Year YDNWR Yukon Delta National Wildlife Reserve 6/5/15 vi Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report 1.0 INTRODUCTION This report has been prepared for the Alaska Village Electric Cooperative (AVEC) to evaluate options for the incorporation of wind power into the existing power generation system in New Stuyahok, AK. The installation of wind turbines in New Stuyahok is being analyzed to reduce AVEC's dependence on imported diesel fuel and provide rural communities an alternative source of renewable energy for power generation. Preliminary findings included in the Alaska Energy Authority (AEA) high resolution wind resource map (Figure 1) indicates New Stuyahok has a Class 2 wind resource, which categorizes the location as marginal. Analysis in this report includes an assessment of the wind resource, wind turbine generator comparison, conceptual design of required site improvements, construction cost estimate, and an economic analysis of the preferred turbine array. This report will also identify the condition of existing power systems within New Stuyahok and outline proposed utility upgrades within the community. Figure 1: AEA Wind Resource Map 6/5/15 1 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report 1.1 CONTACTS The following individuals contributed valuable information for this report: Forest Button AVEC Project Manager Onya Stein AVEC Project Support 1.2 COMMUNITY DESCRIPTION New Stuyahok is located approximately 90 miles upstream of Dillingham on the northern bank of the Nushagak River. The geographic coordinates are 59.4528 North Latitude and -157.3119 West Longitude. The community is located within Bristol Bay Recording District. New Stuyahok is only accessible by air and water. The community is approximately 12 river miles from Ekwok and 52 air miles from Dillingham. A State of Alaska Department of Transportation (DOT&PF) owns and operates a 3,282 feet gravel runway which facilities air transportation to the community. Barge shipments each summer provide the community with required bulk materials. Snow machines, ATV's, and skiffs are the primary means of local transportation. New Stuyahok has a population of 499 year-round residents (2014 Department of Labor Estimate). The community relies heavily on fishing and other subsistence activities. The local economy in New Stuyahok is primarily based on commercial fishing and local wage positions at the school, city, and native corporation facilities. New Stuyahok Village is a federally recognized tribe. 1.3 EXISTING ELECTRICAL POWER SYSTEMS Existing New Stuyahok Power Plant The existing New Stuyahok power plant was energized in 1972 by AVEC. The plant currently provides power to 103 residential consumers, 11 community facilities, and 41 Non-PCE consumers. The power plant is located south of the town center near the new school. The power plant building is a modular structure with metal roof and siding constructed on a shallow foundation. The building is in good condition and was relocated to its current location during construction of the new AVEC tank farm in 2011. There are three diesel generators installed in the existing power plant with a total capacity of 1367 kW. Engine cooling is accomplished by two external radiators located on a steel deck outside the power plant. Power is generated at 277/480V 3-phase with a step-up transformer bank located on a gravel pad adjacent to the power plant to provide 7.2 kV distribution. The manual paralleling switchgear is manufactured by General Electric. 6/5/15 2 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report The power plant contains the following generator sets: (1) Cummins QSX15 G9 (1800 RPM) - 499 kW dieselgenerator (Installed in 2003) (1)Detroit Diesel S60K4c (1800 RPM)-363kW dieselgenerator (1) Caterpillar 3456 - 505 kW dieselgenerator (Installed in 2010) 1367 kW TotalGeneration Capacity The power plant also includes generator appurtenances, day tank, miscellaneous tools and equipment, transfer pump, starting batteries, and station service equipment. The building contains an exhaust hood and radiator stand for each generator. Figure 2: New Stuyahok Power Plant Existing Ekwok Power Plant The existing Ekwok power plant was energized in 1972 . AVEC took over ownership and operation of the power plant in 2011. The plant currently provides power to 52 residential consumers, 5 community facilities, and 22 Non-PCE consumers. Because the planned New Stuyahok-Ekwok Intertie project will eliminate the need for prime power from this plant, the Ekwok power plant was not analyzed within this report. Upon completion of the intertie, AVEC plans to provide backup power to the community with the existing power plant facility. 6/5/15 3 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report 1.4 ELECTRICAL DEMAND AND EFFICIENCIES New Stuyahok Power System According to Power Cost Equalization (PCE) statistical data for fiscal year 2014, the New Stuyahok power plant generated a total of 1,378,601 kWh. From the total power generated, 568,188 kWh were sold to PCE-eligible consumers at a base rate of $0.63/kWh and effective rate of $0.20/kWh. The powerhouse consumed 32,127 kWh, or 2.3% of total power generated, and the distribution system experienced line losses of 1.4%. Additional statistical data measured by the PCE is presented in Table 1.4. Ekwok Power System According to Power Cost Equalization (PCE) statistical data for fiscal year 2014, the Ekwok power plant generated a total of 532,671 kWh. From the total power generated, 195,547 kWh were sold to PCE-eligible consumers at a base rate of $0.68/kWh and effective rate of $0.21/kWh. The powerhouse consumed 31,466 kWh, or 5.9% of total power generated, and the distribution system experienced line losses of 6.2%. Additional statistical data measured by the PCE is presented in Table 1.4. Table 1.4: Power Cost Equalization Energy Consumption Data FY14 Community Customers (Residental and Community Facilities) Kilowatts Sold Diesel Fuel Used Effective Rate Paid by Residential Consumer ($/kWh) Gallons Cost ($) Average Fuel Price ($/gallon) Electricity Generated by Diesel (kWh/gallon) New Stuyahok 114 1,326,841 101,469 $444,871 4.38 13.59 0.20 Ekwok 57 468,218 46,990 $202,798 4.32 11.34 0.21 Source: Statistical Report of Power Cost Equalization Program Fiscal Year 2014, Alaska Energy Authority 1.5 PROPOSED COMMUNITY ENERGY PROJECTS 1.5.1 Ekwok - New Stuyahok Intertie In 2012, AVEC was awarded $2,520,000 from the United States Department of Agriculture (USDA) High Cost Energy Grant Program for construction an intertie between the communities of New Stuyahok and Ekwok. The eight mile intertie is currently in the design phase and expected for construction Winter of 2016. AVEC anticipates the intertie to be commissioned by Spring of 2016. 6/5/15 4 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report 2.0 SITE SELECTION AND CONTROL 2.1 PROPOSED WIND TURBINE SITE The proposed wind turbine site was chosen by AVEC based on land availability and proximity to the to the existing power plant and met tower location. The proposed site (Meadow) is located between the abandoned airport to the southwest and a creek ravine to the northeast. The site is approximately 310 feet in elevation and 180 feet higher than the Nushagak River to the south. The proposed site is surrounded by intermittent spruce trees and tall shrubs. 2.2 LAND OWNERSHIP The parcel containing the proposed wind turbine site is owned by Stuyahok Limited. Stuyahok Limited has expressed willingness to cooperate with AVEC on this project. It is anticipated that the site will be leased from Stuyahok Limited to AVEC for construction of the project. 3.0 WIND DATA ACQUISTION AND MODELING 3.1 DATA ACQUISTION On October 10, 2003, a 30 meter meteorological (met) tower (Met Tower A) was installed in a meadow near the apron of the old airport. This met tower recorded wind data until June 7, 2005. AVEC installed an additional met tower (Met Tower B) on the north end of the old airport runway between 2012 and 2014. Because the airport met tower was significantly further from the proposed turbine site, only Met Tower A data was used for the analysis in this report. This wind data represents 21 months of recorded data from the meadow location. Results of the data acquisition and analysis of the wind resource are included in the New Stuyahok Wind-Diesel Analysis dated July 2015 (Appendix B). 3.2 WIND MODELING RESULTS The results of V3's wind modeling are presented in the New Stuyahok Wind-Diesel Analysis dated July 2015 (Appendix B). The collected wind data depicted a Class 2 (marginal) wind resource in New Stuyahok. Modeling was performed with WAsP modeling software to analyze the wind resource near the met tower location. The software predicts the quality of the wind resource by incorporating surrounding topography and terrain information. This information is used to indentify optimal locations for wind tower construction and to analyze the effectiveness of wind turbine alternatives on the existing power generation system. 6/5/15 5 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report 4.0 WIND TURBINE SYSTEM ALTERNATIVES 4.1 NEW STUYAHOK WIND TURBINE ANALYSIS Two types of wind turbines were selected by AVEC for preliminary modeling and cost analysis: Northern Power Systems (NP100C) turbines and the Vestas V27 turbines. These turbines were selected because they can be installed in configurations that provide 195 kW to 450 kW to the existing power generation system and have a proven track record in arctic environments. These configurations are classified as medium wind-diesel penetration systems having a goal to offset 20% to 50% of the community’s energy demand with wind power. A medium penetration system provides a balance between the amount of energy provided and the complexity of the wind generation and integration systems. 4.1.1 Northern Power Systems 100C-24 NP100C-24 turbines are designed for lower wind speeds and a cut in speed of 7 mph to match New Stuyahok's Class 2 wind resource. The proposed NP100C-24's have a 37-meter hub height, permanent magnet, synchronous, direct drive wind generator and have a rated electrical power of 95kW. AVEC Operations has a long history of experience with maintenance and operation of Northern Power Systems turbines. AVEC's technical maintenance staff are skilled with troubleshooting and performing required maintenance on these units. The turbines are manufactured in Barre, Vermont, and replacement parts are readily available. AVEC has previously installed similar turbines with hub heights ranging 30 to 37 meters, in the following rural Alaska villages: Chevak 400kW Emmonak 400kW Gambell 300kW Hooper Bay 300kW Kasigluk 300kW Mekoryuk 200kW Quinhagak 300kW Savoonga 200kW Shaktoolik 200kW Toksook Bay 400kW 3,000 kW AVEC's Existing Total NP100 Turbine Capacity Two configurations of NP100C-24 turbines were analyzed to optimize power penetration for the existing system. The alternatives were selected to provide a maximum power supply between 190 kW to 285kW to the system. 4.1.2 Vestas V27 The second option is installing remanufactured Vestas Wind Systems V27 turbines. Vestas turbines were originally manufactured in Denmark and are presently manufactured under license in India. The V27 is pitch regulated, has a synchronous (induction) generator, active yaw 6/5/15 6 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report control, a 27 meter diameter rotor, 225 kW power output, and is available with 32, 40, or 50 meter tubular towers. St. Paul Island, Alaska currently operates the V27 turbine, and they are presently available to Alaska as a remanufactured unit from Halus Power Systems in San Leandro, California. 4.2 ALTERNATIVE 1: (2) NORTHERN POWER 100C ARCTIC TURBINES Alternative 1 includes the installation of two (2) NP-100C-24 turbines near the met tower site for a maximum generation capacity of 190 kW. This alternative requires the construction of approximately 1200 feet of new access trail and foundation pads. Approximately 2000 feet of distribution line will be required to tie into a three phase pole near the school. 4.3 ALTERNATIVE 2: (3) Northern Power 100C-24 Arctic Turbines Alternative 2 consists of installing three (3) NP-100C-24 turbines near the met tower site for a maximum generation capacity of 285 kW. The alternative includes the construction of approximately 1400 feet of new access trail and foundation pads. Approximately 2200 feet of distribution line will be required to tie into a three phase pole near the school. 4.4 ALTERNATIVE 3: (1) Vestas V27 Alternative 3 consists of installing (1) Vestas V27 turbine near the met tower site for a maximum generation capacity of 225 kW. The alternative includes the construction of approximately 800 feet of new access trail and foundation pads. Approximately 1600 feet of distribution line will be required to tie into a three phase pole near the school. 5.0 DESIGN AND REQUIRED UPGRADES 5.1 REQUIRED POWER PLANT UPGRADES The proposed wind project will require installation of a new automatic paralleling switchgear to replace the existing manual switchgear. The new switchgear will have five sections - one for each diesel generator, one for master controls, and one for distribution feeder breakers. The switchgear will utilize a programmable load controller (PLC) to automatically match the running generator(s) to the community load while monitoring wind generation. The new switchgear will include a SCADA system for remote monitoring of the generation and distribution systems. A fiber optic cable will allow monitoring and control of the power generation. 5.2 GRID BRIDGING ENERGY SYSTEM AVEC Engineering Department has been performing development and integration research on grid bridging energy systems, and seeks to install such systems in communities with renewable sources of power. Grid bridging systems are constructed as a combination of power conversion 6/5/15 7 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report units and ultra capacitors. The system analyzed for incorporation into this project has the capability to store up to 10 MJ power, at a charge and discharge rate of 250 kW. When excess power is recognized within the grid resulting from rising wind production, excess AC power is converted to DC power for temporary storage within the ultra capacitors. When fully charged, the unit is capable of providing 30 seconds of AC power to the grid at a rate of 250kW. By implementing this temporary storage in its power grid, AVEC plans to allow individual diesel engines to idle at lower RPM's or shut down completely during periods of high wind production. The grid bridging system is anticipated to provide a smooth transition between periods of medium/high wind penetration and full diesel generation as wind drops off and diesel generators are brought online to carry the full power load. Additionally, AVEC Operations aims to better control power frequency with these units and optimize wind generation during periods of higher penetration from the turbines. 5.3 ELECTRICAL SYSTEM UPGRADES The NP-100C-21 turbines generate 480V three phase power at 60Hz. Installation of three 480V/7.2 kV step up transformers will be required adjacent to the wind turbine site. Each new transformer will act to isolate single phases from the wind generators, prior to delivering power the overhead distribution lines. 5.4 DISTRIBUTION LINE UPGRADES No existing three phase distribution lines are located near the proposed wind turbine site. The installation of new three phase lines will be required to tie into the local grid. The closest three phase poles identified are located adjacent to the school, approximately 2000 feet south of the site. 5.5 GEOTECHNICAL INFORMATION Based on published literature, the project site is located within the Nushagak-Bristol Bay Lowland Section of the Western Alaska Province. This area consists of primarily flat tundra with scattered hills and moraine knolls with local relief between 50 and 250 feet. The community of New Stuyahok is located on the western shore of the Nushagak River and was constructed at two elevations, one 25 feet above river level and one 40 feet above river level. The proposed project site is located approximately 1400 to 2200 feet northwest of New Stuyahok, and between 400 and 700 feet northeast of the old airport. The Nushagak-Bristol Bay Lowland Section is generally underlain by several hundred feet of morainal deposits and outwash mantled by silt and peat. Permafrost within this section of Alaska is characterized as isolated or discontinuous. Based on the information that we could gather, the following geotechnical investigations have been previously conducted in the area. New Stuyahok Airport Relocation Phase II, Alaska DOT&PF, March 2004 6/5/15 8 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report Upgrades to a Wastewater Lagoon Treatment System in a Rural Sub-arctic Community in Alaska, GV Jones & Associates, Inc. Based on the information in the previous geotechnical reports, organics and peat would be expected at the surface of undisturbed areas and extend to a maximum depth of about 3 feet below the ground surface (bgs). Underlying this organic layer, a layer up to seven (7) feet thick of medium-stiff sandy silt followed by silty sand and sandy silt with varying amounts of gravel and cobbles would be expected. Previously conducted boring extended to a maximum depth of 23 feet bgs, but this last layer is most likely part of several hundred feet of glacial outwash and morainal deposits. Permafrost in this area appears sporadic and was not encountered in the majority of the borings near the project site. However, permafrost was noted in six (6) borings approximately 9,200 feet northwest of the proposed project site at depths approximately between 4.5 and eight (8) feet bgs. The depth of seasonal frost penetration will vary based on the seasonal weather, location, ground cover, and snow accumulation. The depth of seasonal frost penetration could be nine (9) to ten (10) feet bgs in areas that have been disturbed. Groundwater was not encountered in the majority test borings located within a half mile of the proposed project site. Based on the expected site conditions, the site would generally be considered seismic Site Class C. Utilizing the USGS seismic design tool which is based on 2012 International Building Code the following design criteria is estimated of the site: SMS = 0.550 g, SM1 = 0.398 g, SDS = 0.367 g, and SD1= 0.265 g. 5.6 GEOTECHNICAL CONCERNS Based on the expected subsurface conditions, the following geotechnical concerns may influence the project design and need to be considered in the subsurface exploration program. 5.6.1 Peat Highly organic soil, or peat, is problematic due to its low shear strength, high compressibility when subjected to a load, and high moisture content. The foundation system will likely require the removal of the peat layer or bearing below the peat. 5.6.2 Frost Heave Seasonal freezing and thawing within the active layer is problematic when the active layer soils are frost susceptible. Frost heaving is a process in which segregated ice forms within the soil section causing the soils to heave. This can cause foundations to jack out of the ground. Thaw weakening can also occur when the ice melts; the soil is left in a looser state and there is a decrease in soil strength. 5.6.3 Permafrost If encountered, the presence of discontinuous permafrost would add complexity to the design of shallow and deep foundations. Discontinuous permafrost tends to be warm and will be thaw 6/5/15 9 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report sensitive. The effects of the proposed project and global climate change should be accounted for in the design. 5.6.4 Settlement The loading of soils can induce settlement within the soil stratum depending on the soil composition and relative density. In addition, settlement could occur if permafrost soils are allowed to thaw. 5.7 DESIGN ALTERNATIVES The proposed turbines are typically installed on a 37-meter tall, conical, monopole towers. The design of any foundation system depends on the structure, loads, subsurface conditions, and other considerations such as cost. For the proposed turbines some typical foundation systems include: shallow mat foundations and deep pile foundations. The actual foundations that will be used can be determined after the geotechnical investigation is completed, but a pile foundation is the most likely foundation type. Mat foundations may be applicable if permafrost is not encountered at the site. In the discontinuous permafrost areas of western Alaska, structures are typically constructed on pile foundations that extend to depths greater than 35 feet. Such foundations minimize the risk of foundation failure due to thaw settlement and frost jacking. A typical pile foundation would consist of four (4) to eight (8) 16” diameter steel pipe piles with a reinforced concrete pile cap. Excavation of the surface material and placement of an insulated gravel pad is also typical. The project will require construction of between 800 feet and 1,400 feet of 16-foot wide gravel access trail and a 2,600 square foot gravel pad for each turbine. The proposed trail and wind tower pads would typically be 4 feet thick and consist of locally available sands and gravels compacted to 90% of maximum density. The drivable surface of the embankment is typically constructed of 6 inches of crushed aggregate surface course. Topsoil and seed is typically planned for the embankment slopes to minimize erosion of the placed fill. 5.8 GEOTECHNICAL INVESTIGATION A geotechnical investigation should be conducted to support the design of the project. The investigation should be scoped to evaluate and address the geotechnical concerns that may be present at the site and provide the data needed for geotechnical design. Based on the expected subsurface conditions and tower specifications, a typical geotechnical investigation would include borings at the proposed foundation locations. If a pile foundation is utilized, a minimum of two (2) borings should be drilled. To support the design of deep foundations, the borings should extend to a minimum depth of 60 feet. Subsurface data should be collected during drilling to measure soil temperatures and groundwater conditions. At a minimum, laboratory tests should be conducted to measure moisture contents, grain size distribution, salinity, and organic content. 6/5/15 10 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report The typical cost of mobilizing a drill rig and performing soil borings in this region of Alaska is approximately $75,000 to $100,000. 6.0 ECONOMIC EVALUATION 6.1 METHODOLOGY AND APPROACH The New Stuyahok Wind-Diesel Analysis prepared by V3 Energy includes a wind power analysis of the New Stuyahok power system using HOMER energy modeling software with the previously described wind turbine alternatives. The software was configured for a medium penetration system, with the first priority to meet the community's electrical demands and the second priority to serve a secondary load controller and electric boiler to be located at the school. The analysis considered an average diesel price of $5.07 per gallon and heating oil price of $6.01 per gallon for the projected 20-year design life. The modeling assumptions and results of V3's analysis are presented in Appendix B. V3 inserted the power generation and fuel consumption results from the HOMER modeling into the economic modeling program developed by the Institute for Social and Economic Research (ISER). AEA uses the ISER economic model as a standard approach for scoring wind project design and construction grant applications. The ISER model considers the capital cost of construction and annual cost of operations and maintenance and weighs them against the benefit cost savings realized from the volume of displaced diesel fuel required for power generation and heating public facilities. The analysis develops a cost/benefit ratio that can be used to compare wind turbine alternatives. 6.2 ECONOMIC EVALUATION Table 6.2 below summarizes the findings of V3's economic evaluation for each turbine alternative. Table 6.2: Economic Evaluation Summary Alt Annual Wind Generation @ 80% Availability (kWh) AVEC Fuel Displaced By Wind Energy (gal/yr) Heating Oil Displaced by Wind Energy (gal/yr) Average Wind Penetration (%) Maximum Instantaneous Penetration (%) Cost/Benefit Ratio 1 517,548 38,054 12 25 131 0.65 2 742,584 53,406 364 36 195 0.74 3 353,591 25,979 12 17 151 0.51 Source: Annual Energy Production Data taken from V3 Energy's July 2015 New Stuyahok Wind Diesel Analysis 6/5/15 11 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report 7.0 PREFERRED ALTERNATIVE Based on the findings of the wind modeling and economic evaluation, Alternative 2 is the preferred option for New Stuyahok wind project development. This alternative consists of construction of three (3) NP100C-24 turbines at the meadow site, near the 2003 to 2005 met tower location. Each NP100C-24 turbine has the potential to generate 95kW, for an aggregate capacity of 285 kW. The NP100C-24 turbines were determined by AVEC to be the preferred alternative because they match AVEC's existing turbine fleet, so that maintenance and operational procedures are consistent among AVEC's turbine installations. The three turbine installation would allow for redundancy in the system and the ability to perform turbine maintenance without eliminating wind power from the system. During final design and after the lease lot limits are established, the location of the third turbine should be evaluated to maximize the wind resource and mitigate the effect of turbulence on power production. 8.0 ENVIRONMENTAL REQUIREMENTS HDL conducted preliminary research using the most current available data from state and federal agencies to identify environmental resources within the proposed project vicinity. The purpose of the preliminary research was to assist in identifying permitting and regulatory requirements and to ensure all environmental considerations were used in developing the proposed project. Environmental resources identified during preliminary research efforts are shown on the Environmental Resource Location Map located in Appendix D. 8.1 WETLANDS AND WATERS OF THE U.S. Section 404 of the Clean Water Act (CWA) (33 United States Code [U.S.C.] 1344) requires any person, firm, or agency planning to place structures or conduct work in navigable waters of the U.S., or dump, place, or deposit dredged or fill material in waters of the U.S, including wetlands, to apply for and obtain a permit from the U.S. Army Corps of Engineers (USACE). Section 401 of the CWA requires applicants for a Section 404 permit to also obtain a Certificate of Reasonable Assurance from the Alaska Department of Environmental Conservation (ADEC). Nationwide Permit (NWP) 51 for Land Based Renewable Energy Generation Facilities authorizes discharge of fill materials for wind tower construction if loss of wetlands does not exceed one- half acre. The permit also covers utility lines, roads, and parking lots within the wind generation facility. Submittal requirements for NWP 51 include a Pre-Construction Notification. Access roads and transmission lines not within the facility and used to connect the facility to existing infrastructure require separate permitting. NWP 12 (Utility lines) and 14 (Linear transportation) may be used for this purpose if loss of wetlands does not exceed one-half acre for each permit type. Exceedance of the one-half acre thresholds would require an individual 404 permit. National Wetlands Inventory (NWI) data is not available at the proposed project site. The project will require a wetlands delineation to determine the extent of impacts to wetlands and to identify actual 404 permitting requirements. The USACE recommends that wetlands delineations be completed within the designated growing season for specific regions. New 6/5/15 12 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report Stuyahok is located within the Bristol Bay Lowlands ecoregion, with a typical growing season from May 15th to September 10th. 8.2 HISTORIC AND ARCHAEOLOGICAL RESOURCES: AHPA The Alaska Historic Preservation Act (AHPA) (Alaska Statue 41.35.070) requires a review of state-funded projects by the Alaska Office of History and Archaeology (OHA) to determine if historic, prehistoric, or archaeological sites may be adversely affected. Under the AHPA, a proposed project that adversely affects significant cultural resources may not commence until the necessary mitigation or investigation, recording, and salvage of the site, location, or remains is performed. Because the proposed project is state funded project, OHA review and authorization will be required. Should the project receive federal funding or require a federal permit, Section 106 of the National Historic Preservation Act requires project proponents to consider the effects of their actions on properties in or eligible for inclusion in the National Register of Historic Places. Compliance with Section 106 requires consultation with the State Historic Preservation Officer (SHPO). A review of the National Register of Historic Places and Landmarks did not identify known significant historic sites within or adjacent to the proposed project area. Impacts to historic properties are not anticipated where the project proposes to use existing infrastructure. However, consultation per the Alaska Historic Preservation Act or the National Historic Preservation Act will be required to evaluate potential impacts on sites that have not been listed on the National Register of Historic Places. 8.3 FEDERAL AVIATION ADMINISTRATION (FAA) According to the Federal Aviation Administration’s (FAA) Obstruction Evaluation/Airport Airspace Analysis (OEAAA) tool, the proposed wind tower sites would be within proximity to the New Stuyahok airport (CFR Title 14 Part 77). Part 77 regulations require an aeronautical study and filing form 7460-1 for the proposed tower locations to determine that there is no hazard to air navigation. Consultation with the FAA and filing form 7460-1 should be submitted as early in the permitting process as possible. The aeronautical study process includes evaluations by various lines of business, and any identified impacts must be resolved before a final agency determination is issued. A public notice may be issued with a 30-day comment period, adding additional time to permitting process. 8.4 FISH AND WILDLIFE 8.4.1 Anadromous Streams The Alaska Department of Fish and Game (ADF&G) Atlas to the Catalog of Waters Important to the Spawning Rearing, or Migration of Anadromous Fishes indicated there are no anadromous water bodies mapped within the project vicinity. Stream #1 is unnamed and located 0.25 miles north of the project area but has not been identified as anadromous by ADF&G. 6/5/15 13 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report The Nushagak River is an anadromous waterway located 0.5 miles east of the village. All five species of Pacific salmon (Oncorhynchus tshawytscha, O. keta, O. kisutch, O. gorbuscha, O. nerka), along with arctic char (Salvelinus alpinus), sheefish (Stenodus nelma), and whitefish (Coregonus nelsonii) are listed for the river. The proposed project is not expected to have any affects on this waterway. 8.4.2 Migratory Birds Under the Migratory Bird Treaty Act (MBTA) (16 U.S.C. 703) it is illegal for anyone to "take" migratory birds, their feathers, or nests. The U.S. Fish and Wildlife Service (USFWS) Information Planning and Conservation System (IPaC) decision support tool lists eight migratory birds of concern within the project area (Table 8.4.2): Table 8.4.2: Migratory Birds Located within the Project Area Species Name Seasonal Occurrence in Project Area Arctic Tern Breeding (Sterna paradisaea) Fox Sparrow Breeding (Passerella liaca) Kittlitz’s murrelet Breeding (Brachyramphus brevirostris) Red-throated Loon Breeding (Gavia stellata) Rusty Blackbird Breeding (Euphagus carolinus) Short-billed Dowitcher Breeding (Limnodromus griseus) Short-eared Owl Breeding (Asio flammeus) Solitary Sandpiper Breeding (Tringa solitaria) In order to avoid impacts to migratory bird species, USFWS recommends time periods for avoiding vegetation clearing for regions throughout Alaska. For the Bristol Bay/AK Peninsula ecoregion the following avoidance periods apply: Forest or woodland – April 10 through July 15 Shrub or open habitat – May 1 through July 15 Seabird colonies – May 10 through September 15 8.4.3 Threatened and Endangered Species USFWS’s IPaC System tool indicated there are no listed threatened or endangered species under USFWS jurisdiction within the project area. Consultation under Section 7 of the Endangered Species Act (ESA) requires that projects funded or authorized by a federal agency do not jeopardize the existence of any species listed as threatened or endangered under the 6/5/15 14 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report Act or adversely modify their critical habitat. Such consultation is not anticipated for this project. 8.4.1 Bald and Golden Eagles Bald Eagles are protected under the MBTA and the Bald and Golden Eagle Protection Act (16 U.S.C. 668), whereby the "taking" of bald eagles their nests, or eggs is prohibited. The Act defines "take" to include any disturbance that causes, or is likely to cause, injury to an eagle, a decrease in productivity, or nest abandonment by interference with normal breeding, feeding, or sheltering behavior. According to the USFWS's National Bald Eagle Guidelines, a minimum buffer of 660 feet, or as close as similar existing actives that are tolerated, should be maintained between the construction activity and the nest. Prior to construction an eagle and eagle’s nest survey should be completed. If an eagle’s nest is found prior to construction, it may be necessary to prohibit major ground-disturbing activities (land and vegetation clearing) within the breeding season (March 1 through September 1). If it is not possible to avoid disturbance of an eagle or eagles' nest, an Eagle Permit from USFWS would be required. 8.5 NAVIGABLE WATERS According to ADNR Navigable Waters Map there are no navigable waters within the project area. The nearest navigable waterway is the Nushagak River located approximately 0.5 miles to the east of the proposed project site. The United States Coast Guard (USGS) lists the Nushagak River as navigable from the mouth to the Village of Koliganek, located upriver from New Stuyahok. The USACE lists the Nushagak River as navigable from mouth of the Wood River equating to 34 miles of navigable length. 8.6 FLOODPLAINS According to the Federal Emergency Management Agency’s (FEMA) Flood Map Service Center the project area is located within an unmapped flood zone. FEMA has not completed a study to determine flood hazard for the area; therefore, a flood map has not be published. 8.7 CONTAMINATED SITES, SPILLS, AND UNDERGROUND STORAGE TANKS The ADEC Contaminated Sites Database lists two active clean-up sites within the Village of New Stuyahok; both sites are within 0.5 miles from the proposed turbine site. The Southwest Regional School District (SRSD) provided funding to demolish selected school buildings and provide general cleanup of the New Stuyahok Old School Site. The gym and high school building remain on site. Since demolition, numerous small spills have occurred, fill lines from the high school were found to be leaking, and a 150 gallon fuel release at the former elementary school was documented in January 2003. Diesel range organic (DRO) soil contamination cleanup was not completed. Due to lack of funding from the SRSD final site 6/5/15 15 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report cleanup and soil test analysis was not completed and an unknown amount of contaminated soil remains at the site. Site remains active. The former old Alaska Village Electric Cooperative, Inc. (AVEC) tank farm was decommissioned in 2011 and a new AVEC tank farm was built offsite. The old AVEC tank farm operated for 30 years and contained ten 20,000 gallon diesel tanks. The old AVEC site contains an estimated 1,168 cubic yards of diesel contaminated soil. Access to the subsurface contamination is now limited, a containment structure was built onsite for the village’s new tank farm project. Site remains active. Contamination within the proposed project area from known contaminated sites is not anticipated. If an unknown contaminated site is identified during construction, consultation with ADEC regarding how to proceed during construction will be required. 8.8 STATE REFUGES, SANCTUARIES, CRITICAL HABITAT AREAS, AND NATIONAL WILDLIFE REFUGES ADF&G Special Area Regulations list no state refuges, sanctuaries, or critical habitat areas within the project area. The National Forest Service (NFS) refuge locator listed no national wildlife refuges within the project area. 8.9 LAND OWNERSHIP The parcel containing the proposed wind turbine site is reported by AVEC to be owned by Stuyahok Limited. 8.10 LOCAL RESOURCES New Stuyahok’s population, comprised of approximately 499 residents, is predominately Yup’ik Eskimo. The community is located on the Nushagak River about 52 miles northeast of Dillingham. Residents of New Stuyahok rely heavily on subsistence hunting, fishing and trapping resources year round for food, and berry picking during the summer. The primary species typically harvested include salmon, moose, caribou, rabbit, ptarmigan, duck, and geese. 8.11 AIR QUALITY According to Alaska Administrative Code (AAC) 18 AAC 50, New Stuyahok is considered a Class II area. As such, there are designated maximum allowable increases for particulate matter 10 (PM-10) micrometers or less in size, nitrogen dioxide, and sulfur dioxide. Activities in these areas must operate in such a way that they do not exceed listed air quality controls for these compounds. The nature and extent of the proposed project is not likely to increase emissions or contribute to a violation of an ambient air quality standard or cause a maximum allowable increase for a Class II area. 6/5/15 16 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report 8.12 NATIONAL ENVIRONMENTAL POLICY ACT REVIEW Should the project receive federal funding, the project would require preparation of an Environmental Review (ER) document. Similar to an Environmental Assessment (EA), an ER will provide an assessment of potential environmental impacts and identify avoidance, minimization, and mitigation measures. 8.13 ENVIRONMENTAL SUMMARY AND RECOMMENDATIONS Table 8.13 below summarizes environmental data and permit requirements for development of wind turbines at the site outlined within this report. Table 8.13: Environmental Summary Table Requirements Wetlands Wetland delineation and Jurisdictional Determination needed; NWP 12, 14, & 51 if wetlands impacted and impacts less than ½ acre. An individual permit will be required for impacts greater than ½ acre. Historical and Archaeological Low potential for significant cultural sites; OHA review required Anadromous Waters None identified Migratory Birds No clearing shall be preformed between May 1 and July 15, yearly. Bald Eagles Eagle Nest Survey completed prior to construction Threatened and Endangered Species None located near project area Navigable Water Nushagak River; closest navigable waterway Floodplain Project is located in an unmapped flood zone Contaminated Sites None located in project area National Refuges Project is not located within a National Refuge Land Ownership Stuyahok Limited Air Quality Class II Area 9.0 CONCLUSIONS AND RECOMMENDATIONS The analysis performed within this report and the attached Wind-Diesel Analysis indicates New Stuyahok has a Class 2 wind regime. This low wind regime is not ideal for wind power generation. The high costs associated with constructing the access trail and foundations, combined with low wind speeds, and high turbulence at the proposed site result in a cost/benefit ratio of less than 1 for all of the alternatives presented in this report. If AVEC chooses to move forward with the installation of wind turbines, Alternative 2 (three NP100C-24s wind turbines) is the preferred alternative of this wind turbine analysis. The NPC 6/5/15 17 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report 100C-24s turbine is the preferred turbine type based on its low wind speed design and continuity with AVEC’s existing fleet of Northern Power Turbines. The three turbine configuration supplies the highest generation capacity, cost/benefit ratio, and estimated annual energy production of the three alternatives analyzed. We recommend that AVEC investigate additional sites in and around New Stuyahok with a higher ground elevation to increase wind speeds and reduce turbulence. If a new site is selected, the alternatives presented in this report should be re-examined to assess if wind power integration into the New Stuyahok power generation system is economically viable. 6/5/15 18 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report 10.0 REFERENCES Alaska Community Database, Community Information Summaries (CIS). 2015. . http://commerce.state.ak.us/cra/DCRAExternal/Community/Details/e12f5cec-01a1- 48cb-97e8-a0efd9c45949, accessed April 27, 2015. ADEC. 2015. 18 AAC 50 Air Quality Control: As Amended through August 1, 2012. http://dec.alaska.gov/commish/regulations/pdfs/18%20AAC%2050.pdf, accessed April 27, 2015. ADEC. 2015. Alaska Map of Contaminated Sites. http://www.arcgis.com/home/webmap/viewer.html?webmap=315240bfbaf84aa0b827 2ad1cef3cad3, accessed May 06, 2015. ADF&G. 2015. Wildlife Action Plan Section IIIB: Alaska’s 32 Ecoregions. http://www.adfg.alaska.gov/static/species/wildlife_action_plan/section3b.pdf. accessed April 27, 2015. ADF&G. 2015. ADF&G Refuges, Sanctuaries, Critical Habitat Area, Wildlife Ranges. http://www.adfg.alaska.gov/index.cfm?adfg=protectedareas.locator, accessed April 27, 2015. ADF&G. 2015. ADF&G Atlas to the Catalog of Waters Important to the Spawning, Rearing or Migration of Anadromous Fishes. http://www.adfg.alaska.gov/sf/SARR/AWC/, accessed April 27, 2015. ADF&G. Refuges, Sanctuaries, Critical Habitat Areas and Wildlife Refuges. http://www.adfg.alaska.gov/index.cfm?adfg=conservationareas.locator, accessed April 27, 2015. AVEC. 2015. Alaska Village Electric Cooperative: New Stuyahok Community Profile. http://www.avec.org/communities/community.php?ID=28, accessed April 27, 2015. FAA. Obstruction Evaluation/Airport Airspace Analysis (OE/AAA). https://oeaaa.faa.gov/oeaaa, accessed April 27, 2015. FEMA. 2015. FEMA Map Service Center. https://msc.fema.gov/portal, accessed April 27, 2015. NPS. 2015. National Register of Historic Places Program: Research. http://www.nps.gov/nr/research/index.htm, accessed April 27, 2015. Roso, Catherine. Bingham, Newton. Fritz, John E., Stanley, David. March 2004. Geology Data Report New Stuyahok Airport Relocation Phase II. ADOT&PF. Schubert, Daniel H., Daniel J. Gianotti, Kurt Sauers, and Jason Crownholm. Upgrades to a Wastewater Lagoon Treatment System in a Rural Sub-arctic Community in Alaska. Tech. Anchorage: n.p., n.d. CRW Engineering Web. ftp://ftp.crweng.com/CE_698_Wastewater/References%20and%20Articles/Upgrades%2 0to%20Lagoon%20System%20Paper.pdf, accessed May 28, 2015. 6/5/15 19 Alaska Village Electric Cooperative New Stuyahok Wind Project DRAFT Concept Design Report USACE. 2015. Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Alaska Region (Version 2.0). http://www.usace.army.mil/Missions/CivilWorks/RegulatoryProgramandPermits/reg_su pp.aspx, accessed April 27, 2015. USACE. 1995. Corps of Engineers Alaska District Navigable Waters. http://www.poa.usace.army.mil/Portals/34/docs/regulatory/NavWat.pdf, accessed May 06, 2015. USFWS. 2015. U.S. Fish and Wildlife Service IPaC - Information, Planning, and Conservation System. http://ecos.fws.gov/ipac/, accessed April 27, 2015. USFWS. 2015. U.S. Fish and Wildlife Service Land Clearing Guidance for Alaska: Recommended Time Periods to Avoid Vegetation Clearing. accessed April 27, 2015. http://www.fws.gov/alaska/fisheries/fieldoffice/anchorage/pdf/vegetation_clearing.pdf USFWS. 2015. U.S. Fish and Wildlife Service National Wetlands Inventory. http://www.fws.gov/wetlands/Data/Mapper.html, accessed April 27, 2015. Wahrhaftig, Clyde. 1965. Physiographic divisions of Alaska: U.S. Geological Survey Professional Paper 482. 6/5/15 20 APPENDIX A: Wind Project Conceptual Design Drawings NOT FORCONSTRUCTIONALASKA VILLAGE ELECTRIC COOPERATIVE NOT FORCONSTRUCTIONALASKA VILLAGE ELECTRIC COOPERATIVE NOT FORCONSTRUCTIONALASKA VILLAGE ELECTRIC COOPERATIVE NOT FORCONSTRUCTIONALASKA VILLAGE ELECTRIC COOPERATIVE APPENDIX B: V3 Energy's July 2015 New Stuyahok Wind-Diesel Analysis Report New Stuyahok, Alaska Wind-Diesel Analysis Google Earth image of New Stuyahok July 20, 2015 Douglas Vaught, P.E. V3 Energy, LLC Anchorage, Alaska www.v3energy.com New Stuyahok Wind-Diesel Analysis P a g e | i This report was prepared by V3 Energy, LLC under contract to Alaska Village Electric Cooperative to assess the technical and economic feasibility of installing wind turbines in New Stuyahok, Alaska. This analysis is part of a conceptual design project funded by the Renewable Energy Fund administered by the Alaska Energy Authority. Contents Introduction..................................................................................................................................................1 Village of New Stuyahok ...........................................................................................................................1 Village of Ekwok........................................................................................................................................1 Wind Resource..............................................................................................................................................2 Measured Wind Speeds............................................................................................................................4 Wind Roses................................................................................................................................................4 Wind Frequency Rose...........................................................................................................................5 Total Value (power density) Rose.........................................................................................................5 Temperature and Density.........................................................................................................................5 Wind-Diesel Hybrid System Design and Equipment.....................................................................................6 Proposed System Configuration ...............................................................................................................6 Diesel Power Plant....................................................................................................................................7 Wind Turbines...........................................................................................................................................7 Northern Power NPS 100C-24 ..............................................................................................................7 Vestas V27.............................................................................................................................................8 Load Demand................................................................................................................................................9 New Stuyahok Electric Load......................................................................................................................9 Diesel Generators .....................................................................................................................................9 WAsP Modeling, Wind Turbine Layouts .....................................................................................................10 Orographic Modeling..............................................................................................................................10 Wind Turbine Project Site.......................................................................................................................11 Wind Turbine Layout...............................................................................................................................12 WAsP Modeling Results for Turbine Array Options............................................................................14 Economic Analysis.......................................................................................................................................15 Project Capital Cost.................................................................................................................................15 Fuel Cost..................................................................................................................................................15 New Stuyahok Wind-Diesel Analysis P a g e | ii Modeling Assumptions ...........................................................................................................................16 Model Results .........................................................................................................................................17 Northern Power NPS100C-24, three turbines ....................................................................................17 Northern Power NPS100C-24, two turbines.......................................................................................18 Vestas V27, one turbine......................................................................................................................19 Economic Valuation ................................................................................................................................20 Conclusion...................................................................................................................................................21 Appendix A – NPS100C Three Turbine Array, WAsP Wind Farm Report......................................................A Appendix B – NPS100C Two Turbine Array, WAsP Wind Farm Report.........................................................B Appendix C – V27 One Turbine, WAsP Wind Farm Report...........................................................................C New Stuyahok Wind-Diesel Analysis P a g e | 1 Introduction Alaska Village Electric Cooperative (AVEC) is the electric utility for the City of New Stuyahok, Alaska. AVEC was awarded a grant from the Alaska Energy Authority (AEA) to complete conceptual design work for installation of wind turbines with planned construction in 2017. With anticipated completion in summer 2016 of the electrical intertie connecting New Stuyahok to Ekwok, the two villages are modeled as a combined village for this report. Village of New Stuyahok New Stuyahok is located on the Nushagak River, about 12 miles upriver from the village of Ekwok and 52 miles northeast of Dillingham. It is a southern Yupik Eskimo village with Russian Orthodox influences. Residents practice a fishing and subsistence lifestyle. The village is constructed at two elevations, one 25 feet above river level and one about 40 feet above river level. The present location is the third site that villagers can remember. The village moved downriver to the Mulchatna area from the "Old Village" in 1918. During the 1920s and 30s, the village was engaged in herding reindeer for the U.S. government. However, by 1942 the herd had dwindled to nothing, the village had been subjected to flooding, and the site was too far inland to receive barge service. So the village moved downriver again to its present location. Stuyahok appropriately means "going downriver place." The first school was built in 1961. A post office was also established that year. An airstrip was built soon thereafter, and the 1960s saw a 40% increase in the village population. The city was incorporated in 1972. A 2014 population estimate by the State Department of Labor indicates 499 residents in the village. Village of Ekwok Ekwok means "end of the bluff" and is the oldest continuously-occupied Yupik Eskimo village on the Nushagak River. During the 1800s, the settlement was used in the spring and summer as a fish camp and in the fall as a base for berry picking. By 1923, it was the largest settlement along the river. In 1930, a BIA school was constructed. Mail was delivered by dog sled from Dillingham until a post office opened in Ekwok in 1941. Many of the earliest homes in Ekwok were located in a low flat area near the riverbank. After a severe flood in the early 1960s, villagers relocated to the current location on higher ground. The city was incorporated in 1974. A 2014 population estimate by the State Department of Labor indicates 119 residents in the village. New Stuyahok Wind-Diesel Analysis P a g e | 2 Wind Resource New Stuyahok has been monitored for wind resource twice: from 2003 to 2005 in the meadow near the apron of the old airport (Site 0064), and from 2012 to 2014 at the north end of the runway of the old airport (Site 1064). Because the proposed project site is nearest the first met tower study, data from it is referenced in this report. New Stuyahok met tower data synopsis Data start date 10/10/2003 Data end date 7/7/2005 Wind power class (by WPD) Class 2 (marginal) Wind speed average (30 meters) 5.46 m/s measured Wind power density (30 meters) 232 W/m 2 Weibull distribution parameters k = 1.76, c = 6.3 m/s Roughness Class 4.39 (suburban) Power law exponent 0.38 (high wind shear) Frequency of calms (4.0 m/s threshold) 36% Mean Turbulence Intensity 0.151 (IEC 61400-1 3 rd ed. turbulence category A) Topographic map of New Stuyahok New Stuyahok Wind-Diesel Analysis P a g e | 3 Google Earth image of New Stuyahok (view to north) Google Earth image (view to west) New Stuyahok Wind-Diesel Analysis P a g e | 4 Measured Wind Speeds Measured wind speeds in New Stuyahok are fair for wind power development, provided a wind turbine optimized for lower wind speeds is selected. Wind Speed Sensor Summary 30 m anemometer 20 m anemometer Month Mean Max SD Weibull k Weibull c Mean Max Std. Dev. (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) Jan 7.44 19.5 3.10 2.54 8.36 6.43 16.8 2.81 Feb 6.52 20.9 3.58 1.90 7.35 5.59 17.6 3.12 Mar 6.06 21.3 3.34 1.88 6.81 5.31 18.1 2.94 Apr 5.97 20.0 3.51 1.76 6.71 5.19 17.3 3.08 May 4.56 19.5 3.08 1.52 5.07 3.95 15.9 2.59 Jun 4.68 17.6 2.94 1.63 5.23 3.98 14.4 2.44 Jul 3.98 15.9 2.22 1.89 4.49 3.40 12.9 1.92 Aug 4.38 14.6 2.49 1.84 4.93 3.68 12.6 2.16 Sep 4.58 13.1 2.76 1.68 5.12 3.87 11.5 2.51 Oct 5.99 20.7 2.98 2.08 6.74 5.11 17.0 2.64 Nov 5.58 21.9 3.09 1.87 6.29 4.69 18.7 2.74 Dec 5.85 20.9 3.31 1.83 6.58 4.99 19.0 2.98 All data 5.46 21.9 3.26 1.77 6.29 4.67 19.0 2.87 New Stuyahok Site 0064 wind speed graph Wind Roses Winds at the New Stuyahok met tower test site are primarily northerly with occasional southerly winds. The power density rose indicates, however, that power producing winds at the site are predominately New Stuyahok Wind-Diesel Analysis P a g e | 5 north-northeast and to a lesser extent south-southeast. Ideally, multiple wind turbines should oriented on an east-west axis to avoid turbine shadowing. Note that a wind threshold of 4.0 m/s was selected for the definition of calm winds. With this threshold, the New Stuyahok 0064 (2003 to 2005) met tower site experienced 36 percent calm conditions during the test period. Wind Frequency Rose Total Value (power density) Rose Temperature and Density Over the reporting period, New Stuyahok had an average temperature of 1.7° C. The minimum recording temperature during the measurement period was -32.9° C and the maximum temperature was 28.5° C. Consequent to New Stuyahok’s cool temperatures, the average air density of 1.275 kg/m 3 is approximately five percent higher than the standard air density of 1.217 kg/m 3 (at 14.5° C temperature and 100.46 kPa pressure at 70 m elevation). Temperature and density table Temperature Air Density Month Mean Min Max Std. Dev.Mean Min Max (°C)(°C)(°C)(°C)(kg/m³)(kg/m³)(kg/m³) Jan -12.0 -31.1 2.7 7.37 1.341 1.269 1.446 Feb -6.5 -32.9 5.5 9.02 1.314 1.256 1.457 Mar -6.3 -29.9 6.6 7.72 1.313 1.251 1.439 Apr -0.1 -24.1 16.0 6.93 1.283 1.210 1.405 May 8.5 -2.6 20.2 3.86 1.243 1.193 1.294 Jun 12.6 0.9 27.2 4.70 1.225 1.165 1.277 Jul 15.1 4.8 28.5 4.26 1.214 1.160 1.259 Aug 14.8 2.8 27.3 4.50 1.216 1.165 1.268 Sep 6.3 -4.9 17.2 4.57 1.253 1.205 1.305 New Stuyahok Wind-Diesel Analysis P a g e | 6 Temperature Air Density Month Mean Min Max Std. Dev.Mean Min Max (°C)(°C)(°C)(°C)(kg/m³)(kg/m³)(kg/m³) Oct 1.8 -11.5 11.3 4.43 1.273 1.230 1.338 Nov -3.3 -23.5 8.4 7.24 1.298 1.243 1.402 Dec -10.0 -31.5 3.9 8.32 1.331 1.263 1.448 All data 1.7 -32.9 28.5 11.11 1.275 1.160 1.457 Wind-Diesel Hybrid System Design and Equipment Wind-diesel power systems are categorized based on their average penetration levels, or the overall proportion of wind-generated electricity compared to the total amount of electrical energy generated. Commonly used categories of wind-diesel penetration levels are very low, low, medium, and high penetration. The wind penetration level is roughly equivalent to the amount of diesel fuel displaced by wind power. Note however that the higher the level of wind penetration, the more complex and expensive a control system and demand-management strategy is required. Categories of wind-diesel penetrationlevels Penetration Category Wind Penetration Level Operating Characteristics and System Requirements Instantaneous Average Very Low <60% <8%Diesel generator(s) runs full time Wind power reduces net load on diesel All wind energy serves primary load No supervisory control system Low 60 to 120% 8 to 20%Diesel generator(s) runs full time At high wind power levels, secondary loads are dispatched to insure sufficient diesel loading, or wind generation is curtailed Relatively simple control system Medium 120 to 300% 20 to 50%Diesel generator(s) runs full time At medium to high wind power levels, secondary loads are dispatched to insure sufficient diesel loading At high wind power levels, complex secondary load control system is needed to ensure heat loads do not become saturated Sophisticated control system High (Diesels-off Capable) 300+% 50 to 150%At high wind power levels, diesel generator(s) may be shut down for diesels-off capability Auxiliary components required to regulate voltage and frequency Sophisticated control system Proposed System Configuration Medium penetration is a good compromise between of displaced fuel usage and relatively minimal system complexity and is AVEC’s preferred system configuration. Installation of wind turbines at the New Stuyahok project site would be configured at the medium penetration level. New Stuyahok Wind-Diesel Analysis P a g e | 7 Diesel Power Plant Electric power (comprised of the diesel power plant and the electric power distribution system) in New Stuyahok is provided by AVEC with the following diesel configuration. New Stuyahok power plantdiesel generators Generator Electrical Diesel Engine Model Generator 1 499 kW Cummins QSX15 G9 Newage NCI534F1 2 363 kW Detroit Diesel S60K4 1800 rpm Kato 6P4-1450 3 505 kW Caterpillar 3456 Cat LC6 Wind Turbines This report considers installation of two or three Northern Power Systems’ NPS 100C-24 wind turbines for 190 kW or 385 kW installed wind capacity, and one Vestas V27 at 225 kW installed capacity, to serve the New Stuyahok and Ekwok combined loads. Northern Power NPS 100C-24 The NPS 100C-24 is rated at 95 kW and is equipped with a permanent magnet, synchronous generator for direct drive (no gearbox) operation. The turbine has a 24.4 meter diameter rotor and will be equipped with a 23 meter tower for this installation. The turbine is stall-controlled and in the proposed version will be equipped with an arctic package enabling continuous operation at temperatures to -40° C. The NPS 100 is the most widely represented village-scale wind turbine in Alaska with a significant number of installations in the Yukon-Kuskokwim Delta and on St. Lawrence Island. The NPS 100 wind turbine is manufactured in Barre, Vermont, USA. More information can be found at http://www.northernpower.com/. The power curve of the NPS 100C-24 is shown below. Northern Power Systems 100 (A model) wind turbines, Toksook Bay, Alaska New Stuyahok Wind-Diesel Analysis P a g e | 8 NPS 100C-24 power and thrust curves Vestas V27 The Vestas V27 was originally manufactured by Vestas Wind Systems A/S in Denmark and is no longer in production in Europe, although the turbine reported is presently manufactured under license in India. For many years the V27 was Vestas’ workhorse wind turbine and many are still in operation worldwide. Present availability of the V27 in Alaska is as a remanufactured unit from Halus Power Systems in San Leandro, California. The V27 is pitch-regulated, has a synchronous (induction) double-wound generator, active yaw control, a 27 meter diameter rotor, is rated at 225 kW power output, and is available at a 32 meter hub height as a standard tower option. More information can be found at http://www.halus.com/. Vestas V27 wind turbines, Saint Paul Island, Alaska V27 power and thrust curves New Stuyahok Wind-Diesel Analysis P a g e | 9 Load Demand This analysis includes stand-alone electric and thermal load demand in New Stuyahok (including inclusion of Ekwok electric load with full operational status of the intertie). New Stuyahok Electric Load New Stuyahok and Ekwok electric load was synthesized with the Alaska Village Electric Load Calculator developed by Mia Devine of AEA in 2005. Reference for the Calculator was AVEC’s 2013 Annual Generation Report. Average combined load of the villages is 237 kW with a 432 kW peak and an average daily load demand of 5,686 kWh. New Stuyahok electric load Diesel Generators The HOMER model was constructed with all three New Stuyahok generators. Information pertinent to the HOMER model is shown in the table below. Note that the New Stuyahok power plant is presently equipped with manual switchgear which would be upgraded to automated switchgear for a wind project. This would enable the diesel generators to automatically operate in parallel with wind turbines and each other. For the HOMER model, the diesel generators are allowed to operate at a no-load 0 100 200 300 400 500 600 Jan Feb Mar Apr May Jun July Aug Sept Oct Nov Dec New Stuyahok/Ekwok Electric Load New Stuyahok Wind-Diesel Analysis P a g e | 10 condition (0 kW) to reflect AVEC’s new grid-bridging wind-diesel control technology with ultra- capacitors. Diesel generator HOMER modeling information Diesel generator Cummins QSX15G9 Detroit Diesel S60K4 Caterpillar 3456 Power output (kW) 499 363 505 Intercept coeff. (L/hr/kW rated)0.04 0.04 0.04 Slope (L/hr/kW output) 0.22 0.22 0.22 Minimum electric load (%) 0% (0 kW) 0% (0 kW) 0% (0 kW) Heat recovery ratio (% of waste heat that can serve the thermal load) 22 22 22 Intercept coefficient – the no-load fuel consumption of the generator divided by its capacity Slope – the marginal fuel consumption of the generator WAsP Modeling, Wind Turbine Layouts WAsP (Wind Atlas Analysis and Application Program) and is PC-based software for predicting wind climates, wind resources and power production from wind turbines and wind farms and was used to model the New Stuyahok terrain and wind turbine performance. WAsP software calculates gross and net annual energy production (AEP) for turbines contained within wind farms, such as an array of two or more turbines in proximity to each other. For s single turbine array, WAsP calculates gross AEP. With one turbine, net AEP is identical to gross AEP as there is no wake loss to consider. Orographic Modeling WAsP modeling begins with import of a digital elevation map (DEM) of the subject site and surrounding area and conversion of coordinates to Universal Transverse Mercator (UTM). UTM is a geographic coordinate system that uses a two-dimensional Cartesian coordinate system to identify locations on the surface of Earth. UTM coordinates reference the meridian of its particular zone (60 longitudinal zones are further subdivided by 20 latitude bands) for the easting coordinate and distance from the equator for the northing coordinate. Units are meters. Elevations of the DEMs are converted to meters (if necessary) for import into WAsP software. A met tower reference point is added to the digital elevation map, wind turbine locations identified, and a wind turbine(s) selected to perform the calculations. WAsP considers the orographic (terrain) effects on the wind (plus surface roughness and obstacles) and calculates how wind flow increases or decreases at each node of the DEM grid. The mathematical model has a number of limitations, including the assumption of overall wind regime of the turbine site is the same as the met tower reference site, prevailing weather conditions are stable over time, and the surrounding terrain at both sites is sufficiently gentle and smooth to ensure laminar, attached wind flow. WAsP software is not capable of New Stuyahok Wind-Diesel Analysis P a g e | 11 modeling turbulent wind flow resulting from sharp terrain features such as mountain ridges, canyons, shear bluffs, etc. Orographic modeling of wind across the site, with the New Stuyahok Site 0064 met tower as the reference site, indicates a fair wind resource on the higher terrain west of the old airport, but a marginal wind resource on the north side of the meadow where the met tower had been located. Photos indicate that this meadow now hosts several structures, forcing the wind turbines to a less-than-optimal placement at a lower elevation toward the ravine north of the meadow. Wind modeling of New Stuyahok site area, plan view Wind Turbine Project Site The project site is Native Corporation land north of the apron of the old airport and approximately 180 meters east of the north end of the old runway. New development on the site precludes placing wind turbines in a more desirable location nearer the airport access road, hence turbine placement is further north than ideal. This location, however, is a compromise that enables turbines to be located at this site area but with sufficient buffer from the new infrastructure. New Stuyahok Wind-Diesel Analysis P a g e | 12 Photograph of wind turbine site area, view to northeast Wind Turbine Layout Using WAsP software, three wind turbine layout arrangements were developed: three NPS 100C-24’s, two NPS 100C-24’s, and one Vestas V27. The wind turbines were aligned to minimize wake loss from the measured prevailing and secondary winds. Site constraints (i.e., new infrastructure) necessitated that the turbines be located beyond the north edge of the meadow in heavy brush and at lower elevation than more ideal terrain further south (nearer the airport access road). NPS 100C-24 Three Turbine Array Turbine UTM (easting, northing)Elevation WTG 1 Zone 4V 594849, 6591764 74.3 WTG 2 Zone 4V 594913, 6591728 84.3 WTG 3 Zone 4V 594976, 6591691 87.5 NPS 100C-24 Two Turbine Array Turbine UTM (easting, northing)Elevation WTG 1 Zone 4V 594913, 6591728 84.3 WTG 2 Zone 4V 594976, 6591691 87.5 Vestas V27 One Turbine Turbine UTM (easting, northing)Elevation WTG 1 Zone 4V 594976, 6591691 87.5 Wind turbine locations New Stuyahok Wind-Diesel Analysis P a g e | 13 NPS 100C-24 three turbine layout, view to south, with WAsP wind speed overlay NPS 100C-24 three turbine layout, view to south, with WAsP wind speed overlay New Stuyahok Wind-Diesel Analysis P a g e | 14 V27 one turbine layout, view to south, with WAsP wind speed overlay WAsP Modeling Results for Turbine Array Options The following tables present the WAsP software analysis of energy production of three and two NPS 100C-24 turbines, and one Vestas V27 turbine, all at 100% turbine availability (percent of time that the turbine is on-line and available for energy production with no energy production losses other than WAsP-calculated wake loss). The NPS 100C-24 wind turbine models relatively well in the New Stuyahok wind regime with acceptable annual energy production and minimal array wake loss. The Vestas V27 is less well optimized for the lower wind speeds at the project site, which is reflected in the modeling results. NPS 100C-24 three turbine array, WAsP model results, 100% AEP Parameter Total (MWh/yr) Mean Each (MWh/yr) Minimum Each (MWh/yr) Maximum Each (MWh/yr) Gross AEP 745.7 248.6 227.7 263.9 Net AEP 717.1 239.0 224.3 252.3 Wake loss 3.83% - - - NPS 100C-24 two turbine array, WAsP model results, 100% AEP Parameter Total (MWh/yr) Mean Each (MWh/yr) Minimum Each (MWh/yr) Maximum Each (MWh/yr) Gross AEP 518.0 259.0 254.0 264.0 Net AEP 505.1 252.6 250.9 254.3 Wake loss 2.49% - - - New Stuyahok Wind-Diesel Analysis P a g e | 15 Vestas V27 one turbine, WAsP model results, 100% AEP Parameter Total (MWh/yr) Mean Each (MWh/yr) Minimum Each (MWh/yr) Maximum Each (MWh/yr) Gross AEP 389.1 389.1 389.1 389.1 Net AEP 389.1 389.1 389.1 389.1 Wake loss 0.0% - - - Economic Analysis Homer software was used to model static energy balance of the New Stuyahok electrical and thermal power system at ten minute increments of time. Wind turbines are modeled as connected to the electrical distribution system with first priority to serve the electrical load and second priority to serve the thermal load via a secondary load controller and electric boiler located at the community school. Project Capital Cost Capital and installation costs of wind turbines to serve the villages of New Stuyahok and Ekwok, including distribution system extension is shown in the table below. These cost estimates were developed by HDL for this conceptual design report. Capital cost Configuration Capital cost (from HDL)Cost/kW 3 Northern NPS100C-24 $5,114,100 $17,944 2 Northern NPS100C-24 $4,130,600 $21,740 1 Vestas V27 $3,625,700 $16,114 Fuel Cost A fuel price of $5.07/gallon was chosen for the initial HOMER analysis by reference to the 2014_06- R8Prototype_AEA_Final_2014-08-07 Excel spreadsheet, written by ISER. The $4.83/gallon price reflects the average value of all fuel prices between the 2017 (the assumed project start year) fuel price of $4.53/gallon and the 2036 (20 year project end year) fuel price of $5.77/gallon using the medium price projection analysis with an average CO2-equivalent allowance cost of $0.60/gallon included. By comparison, the fuel price for New Stuyahok reported to Regulatory Commission of Alaska for the 2014 PCE report was $4.38/gallon, without inclusion of CO2-equivalent allowance. Assuming a CO2- equivalent allowance of $0.42/gallon (ISER Prototype spreadsheet, 2013 value), the New Stuyahok 2014 diesel fuel price was $4.80/gallon. Heating fuel displacement by diversion of excess energy to thermal loads is valued at $6.01/gallon as an average price for the 20 year project period. This price was determined by reference to the 2014_06- R8Prototype_AEA_Final_2014-08-07 Excel spreadsheet where heating oil is valued at the cost of diesel fuel (with CO2-equivalent allowance) plus $0.94/gallon, assuming heating oil displacement between 1,000 and 25,000 gallons per year. New Stuyahok Wind-Diesel Analysis P a g e | 16 Fuel cost table (SCC included) ISER medium cost projection 2017 (/gal)2035 (/gal) Average (/gallon) Diesel fuel $4.53 $5.77 $5.07 Heating oil $5.47 $6.71 $6.01 Modeling Assumptions HOMER energy modeling software was used to analyze the New Stuyahok power System. HOMER is a static energy model designed to analyze hybrid power systems that contain a mix of conventional and renewable energy sources, such as diesel generators, wind turbines, solar panels, batteries, etc. Homer software is widely used in the State of Alaska to aid development of village wind-diesel power projects. HOMER modeling assumptions are detailed in the table below. Many assumptions, such as project life, discount rate, operations and maintenance (O&M) costs, etc. are AEA default values. The base or comparison scenario is the existing New Stuyahok power plant with its present configuration of diesel generators, which also will serve Ekwok by distribution intertie. Wind turbines constructed at the New Stuyahok site are assumed to operate in parallel with the diesel generators. Excess energy will serve thermal loads via a secondary load controller and electric boiler, although the SLC/boiler may not be part of the diesel generator recovered heat loop and could be operated as a remote node. Installation cost of the wind turbines assumes a three-phase distribution line extension from the road to the wind turbine site. Homer and ISER modeling assumptions Economic Assumptions Project life 20 years (2017 to 2036) Discount rate 3% (reference: ISER 2014 R8Prototype spreadsheet) Operating Reserves Load in current time step 10% Wind power output 100% (Homer setting ensure diesels on operation) Fuel Properties (no. 2 diesel for power plant) Heating value 46.8 MJ/kg (140,000 BTU/gal) Density 830 kg/m 3 (6.93 lb./gal) Price (20 year average; ISER 2014, medium projection plus SCC) $5.07/gal Fuel Properties (no. 1 diesel to serve thermal loads) Heating value 44.8 MJ/kg (134,000 BTU/gal) Density 830 kg/m 3 (6.93 lb./gal) Price (20 year average; ISER 2014, medium projection plus SCC) $6.01/gal Diesel Generators Generator capital cost $0 (new generators already funded) O&M cost $0.02/kWh (reference: ISER 2014 R8Prototype spreadsheet) Minimum load 0 percent (grid-bridging control) Efficiency (overall) 13.59 kWh/gal (2014 PCE Report) Schedule Optimized New Stuyahok Wind-Diesel Analysis P a g e | 17 Wind Turbines Net AEP 80% O&M cost $0.050/kWh (reference: ISER 2014 R8Prototype spreadsheet) Wind speed 5.44 m/s at 30 m, measured at met tower 5.55 m/s at 30 m, WAsP est. at met tower 6.20 m/s at 37 m, WAsP avg of 3 NPS100s at site 6.35 m/s at 37 m, WAsP avg of 2 NPS100s at site 6.20 m/s at 32 m, WAsP calc at V27 site Density adjustment 1.280 (from Site 0064 met tower data) Energy Loads Electric 5.69 MWh/day average New Stuyahok and Ekwok electric load Thermal Not modeled Model Results HOMER energy modeling software was used to calculate wind turbine energy production and excess energy available (not demanded by the electrical load). Note that inclusion of wind turbines as a wind- diesel power system, even at lower penetration levels, can result in energy generation greater than electrical load demand. This is due to spinning reserve and minimum loading requirements of the diesel generators. Note that wind turbine energy production in these analyses is calculated at 80 percent of gross. Northern Power NPS100C-24, three turbines This configuration is three Northern Power NPS100C-24 wind turbines at a 37 meter hub height at the proposed wind site presented in the WAsP modeling section of this analysis report. The 10 minute averaging time simulation models wind energy production at 80 percent net (or 80 percent of annual gross) at the turbine site, not the met tower. Homer software predicts 36% average annual wind power penetration and 195% maximum instantaneous (10 minute) wind penetration. Energy table, three NPS 100C-24 turbines, 80% net AEP Month Average Wind Power (kW) Wind Energy (kWh) Average Load (kW) Min Load (kW) Average Excess Power (kW) Excess Energy (kWh) Average Wind Penet. (%) Max Wind Penet. (%) 1 148 110256 267 161 29 2803 59 142 2 114 76936 277 167 33 2036 44 139 3 102 75526 245 151 31 1544 43 145 4 96 68903 241 155 34 1760 41 144 5 56 41732 218 125 19 175 25 138 6 60 42915 197 104 39 638 29 195 7 44 33010 190 90 32 1021 23 170 8 54 40471 211 115 48 1292 26 195 9 66 47596 228 121 44 1763 30 183 10 94 70171 242 132 26 1073 41 160 11 87 62565 257 153 28 1188 36 139 12 97 72502 271 166 28 1504 39 135 Annual 85 742584 237 90 32 16798 36 195 New Stuyahok Wind-Diesel Analysis P a g e | 18 Chart, three NPS 100C-24 turbines Northern Power NPS100C-24, two turbines This configuration is two Northern Power NPS100C-24 wind turbines at a 37 meter hub height at the proposed wind site presented in the WAsP modeling section of this analysis report. The 10 minute averaging time simulation models wind energy production at 80 percent net (or 80 percent of annual gross) at the turbine site, not the met tower. Homer software predicts 25% average annual wind power penetration and 131% maximum instantaneous (10 minute) wind penetration. Energy table, two NPS 100C-24 turbines, 80% net AEP Month Average Wind Power (kW) Wind Energy (kWh) Average Load (kW) Min Load (kW) Average Excess Power (kW) Excess Energy (kWh) Average Wind Penet. (%) Max Wind Penet. (%) 1 102 76090 267 161 0 0 41 95 2 79 53356 277 167 0 0 31 93 3 71 52543 245 151 0 0 30 97 4 67 47943 241 155 0 0 29 96 5 40 29473 218 125 0 0 18 94 6 42 30266 197 104 14 59 21 131 7 31 23248 190 90 11 35 16 113 8 38 28277 211 115 20 160 19 130 9 46 33131 228 121 14 128 21 122 10 66 49135 242 132 7 10 29 106 11 61 43722 257 153 0 0 25 93 12 68 50364 271 166 0 0 27 90 Annual 59 517548 237 90 15 393 25 131 0 50 100 150 200 250 0 50 100 150 200 250 300 1 2 3 4 5 6 7 8 9 10 11 12 Axis Title New Stuyahok+Ekwok, 3 NPS100C-24 Turbines Average Wind Power (kW)Average Load (kW)Min Load (kW) Average Wind Penet. (%)Max Wind Penet. (%) New Stuyahok Wind-Diesel Analysis P a g e | 19 Chart, two NPS 100C-24 turbines Vestas V27, one turbine This configuration is one Vestas V27 wind turbine at a 32 meter hub height at the proposed wind site presented in the WAsP modeling section of this analysis report. The 10 minute averaging time simulation models wind energy production at 80 percent net (or 80 percent of annual gross) at the turbine site, not the met tower. Homer software predicts 17% average annual wind power penetration and 151% maximum instantaneous (10 minute) wind penetration. Energy table, one V27 turbine, 80% net AEP Month Average Wind Power (kW) Wind Energy (kWh) Average Load (kW) Min Load (kW) Average Excess Power (kW) Excess Energy (kWh) Average Wind Penet. (%) Max Wind Penet. (%) 1 76 56815 267 161 3 12 31 104 2 58 38739 277 167 5 27 23 106 3 50 36903 245 151 6 8 21 106 4 47 34027 241 155 8 30 20 110 5 23 17129 218 125 0 0 10 77 6 25 17817 197 104 21 17 12 134 7 19 14252 190 90 20 92 10 128 8 25 18872 211 115 30 164 12 151 9 32 22734 228 121 27 163 14 136 10 43 31850 242 132 13 22 19 119 11 40 28716 257 153 6 3 16 106 12 48 35737 271 166 0 0 19 100 Annual 40 353591 237 90 16 538 17 151 0 20 40 60 80 100 120 140 160 180 0 50 100 150 200 250 300 1 2 3 4 5 6 7 8 9 10 11 12 Axis Title New Stuyahok+Ekwok, 2 NPS100C-24 Turbines Average of Wind Power (kW)Average of Load (kW) Min of Load (kW)Average of Wind Penet. (%) Max of Wind Penet. (%) New Stuyahok Wind-Diesel Analysis P a g e | 20 Chart, one V27 turbine Economic Valuation Homer software was used in this feasibility analysis to model the wind resource, wind turbine energy production, effect on the diesel engines when operated with wind turbines, and excess wind energy that could be used to serve thermal loads. Although Homer software is designed to evaluate economic valuation by ranking alternatives, including a base or “do nothing” alternative by net present cost, AEA economic valuation methodology differs in its assumptions of O&M costs, fuel cost for each year of the project life, and disposition of excess energy. Excess energy is valued in the ISER spreadsheet with an assumption that the power plant is not co-generation. In other words, excess energy is valued without consideration of possible thermal production loss due to reduced diesel engine loading as would occur in a co-generation system configuration. In an effort to align economic valuation of project alternatives with Alaska Energy Authority methods, this feasibility analysis uses AEA’s economic evaluation methods. Although ISER developed the cost evaluation spreadsheet, AEA determined the assumptions and methods of the model. The model is updated every July in preparation for the next round of Renewable Energy Fund requests for proposals in the form of an explanation report and an Excel spreadsheet. The latest version of the spreadsheet has a file name of 2014_06-R8Prototype_AEA_Final_2014-08-07 and is available on AEA’s website. Project economic valuation No. Capacity (kW) Diesel Fuel Saved (gal/yr) Heat Oil Saved (gal/yr) Petroleum Fuel Saved (gal/yr) (in $ millions) Turbine Project Cost NPV Benefits NPV Costs B/C ratio NPS 100C-24 3 300 5.11 3.37 4.54 0.74 53,406 364 53,770 2 200 4.13 2.38 3.67 0.65 38,054 12 38,066 0 20 40 60 80 100 120 140 160 0 50 100 150 200 250 300 1 2 3 4 5 6 7 8 9 10 11 12 Axis Title New Stuyahok+Ekwok, 1 V27 Turbine Average Wind Power (kW)Average Load (kW)Min Load (kW) Average Wind Penet. (%)Max Wind Penet. (%) New Stuyahok Wind-Diesel Analysis P a g e | 21 No. Capacity (kW) Diesel Fuel Saved (gal/yr) Heat Oil Saved (gal/yr) Petroleum Fuel Saved (gal/yr) (in $ millions) Turbine Project Cost NPV Benefits NPV Costs B/C ratio V27 1 225 3.63 1.63 3.22 0.51 25,979 12 25,991 Conclusion New Stuyahok has a moderate wind resource for wind power development. Wind behavior at the met tower sites demonstrates low extreme wind probability but moderately high to high turbulence due to heavy brush to the north. Constraints limit the project site to the north side of the now developed meadow near the apron of the old airport, but ideally, a site less exposed to turbulence-inducing vegetation could be found. All three modeled wind turbine configurations are medium penetration options and controllable with a secondary load controller/boiler configuration, either in a recovered heat loop or as a remote node. Economic benefit of the projects model as moderate. This is due to the modest wind resource at the selected wind turbine site and the high project construction costs. New Stuyahok Wind-Diesel Analysis P a g e | A Appendix A – NPS100C Three Turbine Array, WAsP Wind Farm Report C:\Users\Douglas\Documents\AVEC\New Stuyahok - Site 0064\2015 CDR, TO 15.05\WAsP report, New Stu, 3 NPS100C-24, HDL's new sites.docx 1 09-07-15 'New Stuyahok, three NPS100C’s' wind farm Produced on 4/23/2015 at 12:36:10 PM by licenced user: Douglas J. Vaught, V3 Energy, USA using WAsP version: 10.02.0017. Parameter Total Average Minimum Maximum Net AEP [MWh] 690.481 230.160 215.930 243.064 Gross AEP [MWh] 718.119 239.373 219.240 254.133 Wake loss [%] 3.85 - - - Site Location [m] Turbine Elevation [m a.s.l.] Height [m a.g.l.] Net AEP [MWh] Wake loss [%] WTG 1 (594849.5,65917 64.0) NPS100C-24 74.29062 37 215.930 1.51 WTG 2 (594913.0,65917 28.0) NPS100C-24 84.31248 37 231.487 5.42 WTG 3 (594976, 6591691) NPS100C-24 87.49069 37 243.064 4.36 Site Location [m] Height [m a.g.l.] A [m/s] k U [m/s] E [W/m²] RIX [%] dRIX [%] WTG 1 (594849.5,65917 64.0) 37 5.9 1.81 5.26 190 0.9 -0.2 WTG 2 (594913.0,65917 28.0) 37 6.3 1.80 5.57 227 1.2 0.1 WTG 3 (594976, 6591691) 37 6.4 1.85 5.66 231 1.1 -0.1 The wind farm lies in a map called 'New Stuyahok'. C:\Users\Douglas\Documents\AVEC\New Stuyahok - Site 0064\2015 CDR, TO 15.05\WAsP report, New Stu, 3 NPS100C-24, HDL's new sites.docx 2 09-07-15 The wind farm is in a project called 'New Stuyahok' A wind atlas called 'Wind atlas 1' was used to calculate the predicted wind climates The map was imported by 'Douglas' from a file called 'C:\Users\Douglas\Documents\AVEC\New Stuyahok - Site 0064\WAsP\New Stuyahok.map', on a computer called 'V3ENERGYGATEWAY'. The map file data were last modified on the 2/21/2014 at 5:03:23 AM There is no information about the origin of the wind atlas associated with this wind farm. The wind turbine generator associated with this wind farm was imported by 'Douglas' from a file called 'C:\Users\Douglas\Documents\Wind Turbines\WAsP turbine curves\NPS100C-24, 37 meter.wtg', on a computer called 'V3ENERGYGATEWAY'. The wind turbine generator file was last modified on the 8/28/2014 at 3:15:58 PM The wind farm is in a project called New Stuyahok. All of the parameters in the project are default values. New Stuyahok Wind-Diesel Analysis P a g e | B Appendix B – NPS100C Two Turbine Array, WAsP Wind Farm Report C:\Users\Douglas\Documents\AVEC\New Stuyahok - Site 0064\2015 CDR, TO 15.05\WAsP report, New Stu, 2 NPS100C-24, HDL's new sites.docx 1 09-07-15 'New Stuyahok, two NPS100’s' wind farm Produced on 7/9/2015 at 11:48:20 AM by licenced user: Douglas J. Vaught, V3 Energy, USA using WAsP version: 10.02.0017. Parameter Total Average Minimum Maximum Net AEP [MWh] 505.129 252.565 250.870 254.260 Gross AEP [MWh] 518.041 259.020 254.081 263.960 Wake loss [%] 2.49 - - - Site Location [m] Turbine Elevation [m a.s.l.] Height [m a.g.l.] Net AEP [MWh] Wake loss [%] WTG 2 (594913, 6591728) NPS100C-24 84.21686 37 250.870 1.26 WTG 3 (594976, 6591691) NPS100C-24 87.49069 37 254.260 3.67 Site Location [m] Height [m a.g.l.] A [m/s] k U [m/s] E [W/m²] RIX [%] dRIX [%] WTG 2 (594913, 6591728) 37 6.3 1.80 5.57 237 1.2 0.1 WTG 3 (594976, 6591691) 37 6.4 1.85 5.66 241 1.1 -0.1 The wind farm lies in a map called 'New Stuyahok'. New Stuyahok Wind-Diesel Analysis P a g e | C Appendix C – V27 One Turbine, WAsP Wind Farm Report C:\Users\Douglas\Documents\AVEC\New Stuyahok - Site 0064\2015 CDR, TO 15.05\WAsP report, New Stu, 1 V27, HDL's new sites.docx 1 09-07-15 'New Stuyahok, one V27' wind farm Produced on 7/9/2015 at 12:15:09 PM by licenced user: Douglas J. Vaught, V3 Energy, USA using WAsP version: 10.02.0017. Parameter Total Average Minimum Maximum Net AEP [MWh] 389.155 389.155 389.155 389.155 Gross AEP [MWh] 389.155 389.155 389.155 389.155 Wake loss [%] 0.0 - - - Site Location [m] Turbine Elevation [m a.s.l.] Height [m a.g.l.] Net AEP [MWh] Wake loss [%] WTG 3 (594976, 6591691) Vestas V27 (225 kW) 87.49069 32 389.155 0.0 Site Location [m] Height [m a.g.l.] A [m/s] k U [m/s] E [W/m²] RIX [%] dRIX [%] WTG 3 (594976, 6591691) 32 6.2 1.81 5.54 231 1.1 -0.1 The wind farm lies in a map called 'New Stuyahok'. APPENDIX C: Construction Cost Estimate Concept Level EstimateNew StuyahokAlternatives Cost Summary 7/17/2015SUMMARY Estimated Construction Estimated ConstructionCost Cost/ Installed kWAlternative 1 - (2) Northern Power 100C-24 Turbines $ 4,130,600.00 190 $ 21,740.00 Monopole Alternative 2 - (3) Northern Power 100C-24 Turbines $ 5,114,100.00 285 $ 17,944.21 Monopole Alternative 3 - (1) Vestas V27 $ 3,625,700.00 285 $ 16,114.22 Monopole Description Installed kW Tower Type Concept Level Estimate New Stuyahok Wind CDR Alternative 1 5/21/15 Item Estimated Quantity Description Unit Price ($) Subtotal ($) Alternative 1 - (2) Northern Power 100C-24 Turbines 1 7,600 CY Borrow 55 418,000 2 4700 SY Geotextile 4 18,800 3 2 Each Pile Cap Foundation 180,000 360,000 4 2 Each Northern Power Systems NPS-100B-21 Arctic Wind Turbines 347,000 694,000 5 2,000 LF Install Conductor to 3 Phase Pole Near School 59 118,000 6 1 Each Transformer 12,000 12,000 7 1 Sum Wireless Communication System 75,000 75,000 8 1 Sum Wind Turbine Power Integration w/ Remote Boiler 150,000 150,000 9 1 Sum Swichgear Upgrade 150,000 150,000 10 1 Sum Grid Briding System 500,000 500,000 11 1 Sum Labor 227,000 227,000 12 1 Sum Equipment 186,000 186,000 13 1 Sum Materials and Equipment Freight (Seattle to New Stuyahok) 400,000 400,000 14 2 Each Turbine Freight (VT to Seattle) 48,500 97,000 15 1 Sum Indirects 186,000 186,000 Subtotal Construction 3,591,800$ Land Acquisition -$ Project Contingency @ 15% 538,800$ 0 Years Inflation @ 2% -$ Total 4,130,600$ Installed Generation Capacity 190 kW Total Cost 4,130,600$ Cost/Installed kW $21,740 Concept Level Estimate New Stuyahok Wind CDR Alternative 2 5/21/15 Item Estimated Quantity Description Unit Price ($) Subtotal ($) Alternative 2 - (3) Northern Power 100C-24 Turbines 1 9,300 CY Borrow 55 511,500 2 5,750 CY Geotextile 4 14,000 3 3 Each Pile Cap Foundation 180,000 540,000 4 3 Each Northern Power Systems NPS-100B-21 Arctic Wind Turbines 347,000 1,041,000 5 2,000 LF Install Conductor to 3 Phase Pole Near School 59 118,000 6 1 Each Transformer 12,000 12,000 7 1 Sum Wireless Communication System 75,000 75,000 8 1 Sum Wind Turbine Power Integration w/ Remote Boiler 150,000 150,000 9 1 Sum Swichgear Upgrade 150,000 150,000 10 1 Each Grid Briding System 500,000 500,000 11 1 Sum Labor 280,000 280,000 12 1 Sum Equipment 230,000 230,000 13 1 Sum Materials and Equipment Freight (Seattle to New Stuyahok) 450,000 450,000 14 3 Each Turbine Freight (VT to Seattle) 48,500 145,500 15 1 Sum Indirects 230,000 230,000 Subtotal Construction 4,447,000$ Land Acquisition -$ Project Contingency @ 15% 667,100$ 0 Years Inflation @ 2% -$ Total 5,114,100$ Installed Generation Capacity 285 kW Total Cost 5,114,100$ Cost/Installed kW $17,944 Concept Level Estimate New Stuyahok Wind CDR Alternative 3 5/21/15 Item Estimated Quantity Description Unit Price ($) Subtotal ($) Alternative 3 - (1) Vestas V27 1 5,000 CY Borrow 55 275,000 2 3200 SY Geotextile 4 12,800 3 1 Each Pile Cap Foundation 325,000 325,000 4 1 Each Northern Power Systems V27 Wind Turbine 455,000 455,000 5 2,000 LF Install Conductor to 3 Phase Pole Near School 59 118,000 6 1 Each Transformer 12,000 12,000 7 1 Sum Wireless Communication System 75,000 75,000 8 1 Sum Wind Turbine Power Integration w/ Remote Boiler 150,000 150,000 9 1 Sum Swichgear Upgrade 150,000 150,000 10 1 Each Grid Briding System 500,000 500,000 11 1 Sum Labor 200,000 200,000 12 1 Sum Equipment 165,000 165,000 13 1 Sum Materials and Equipment Freight (Seattle to New Stuyahok) 500,000 500,000 14 1 Each Turbine Freight (CA to Seattle) 50,000 50,000 15 1 Sum Indirects 165,000 165,000 Subtotal Construction 3,152,800$ Land Acquisition -$ Project Contingency @ 15% 472,900$ 0 Years Inflation @ 2% -$ Total 3,625,700$ Installed Generation Capacity 225 kW Total Cost 3,625,700$ Cost/Installed kW $16,114 APPENDIX D: Environmental Resource Location Map Proposed Turbine Site #1 Proposed Turbine Site #2 (Alternative 2 Only) Spectacled Eider Breeding Habitat Yukon Delta National Widlife Refuge Anadromous waters #ADEC Active Contaminated Sites Appendix D Environmental Resource Location Map Alaska Villiage Electric Cooperative Eek Wind Project Concept Design Report Date: May 2015 Township 2 N Range 74W USGS Quad Map Hooper Bay D-2 60°12' 55.96"N 162°00'41.62"W Eek, Alaska Eek Anchorage