17-08-2012, 01:10 PM
Deering Wind-Diesel Hybrid Feasibility Study Report
Deering Wind-Diesel.pdf (Size: 3.58 MB / Downloads: 66)
Introduction
Northwest Alaska is an area with abundant wind energy resources. In 2007, the U.S. Department of Energy’s Tribal Energy Program awarded NANA Regional Corporation (NRC) grant #DE-FG36-07GO17076 to fund a Wind Resource Assessment Project (WRAP) for the NANA region. The Deering wind site was identified on a ridge near Cape Deceit, about one mile west of the community. A meteorological (“met”) tower owned by the Alaska Energy Authority was installed at this location in August 2008 as part of the NANA WRAP study efforts and was removed in May 2011.
In 2009, AEA (with approval from the state legislature) awarded a $10,750,000 Renewable Energy Fund grant to the Northwest Arctic Borough (NWAB) for design and construction of wind-diesel projects in Deering, Buckland, and Noorvik. The feasibility study/conceptual design phase of this grant began in September 2010.
Village of Deering
Deering is located on Kotzebue Sound at the mouth of the Inmachuk River, 57 miles southwest of Kotzebue. It is built on a sand and gravel spit 300 feet wide and a half-mile long. According to Census 2010, there are 61 housing units in the community and 44 are occupied. Its population of 122 people is 87 percent Alaska Native, 9 percent white and 4 percent multi-racial. Deering is located in the transitional climate zone, which is characterized by long, cold winters and cool summers. Annual snowfall averages 36 inches, and total precipitation averages 9 inches per year. Kotzebue Sound is ice-free from early July until mid-October.
Potential Alternative Energy Resources
At present, all of Deering’s electrical power is generated with diesel generators, all of its space and water heating (thermal) needs are supplied by heating oil (diesel fuel), and all mechanized transportation powered by diesel or gasoline internal combustion engines, making the village one hundred percent dependent on the import of fossil fuel for its energy supply.
Regarding the supply of alternative or renewable energy resources, a 1979 study by the U.S. Department of Energy concluded that there are no potential hydroelectric sites near enough to Deering to develop for village power needs.
Deering’s Electric Power System
Electric power is provided to Deering by Ipnatchiaq Electric Company (IEC), a subsidiary of the City of Deering. The power plant is co-located with a water treatment plan and washeteria. The combined facilities were constructed in early 2000 to replace and upgrade earlier systems. Five diesel generator units are installed at the power plant: four are primary units to serve the village electrical load and a fifth generator is for station service and water plant power only.
The power plant and water treatment plant and washeteria were co-located to enable use of energy from diesel engine water jacket recovered heat to supplement fuel oil boilers in the water facility.
The power plant, designed by the Alaska Energy Authority, incorporates switchgear manufactured by Controlled Power, Inc. that is intended to be adaptable to wind power integration. An Allen-Bradley PLC is incorporated into the controls and is designed to automate the operation of the power plant.
The village-wide electrical distribution system consists of three feeders: one to the east of the plant, one to the west, and one dedicated to the treatment plant. Each feeder is three phase.
Operational Issues
A number of substantial issues and problems have been identified that impact an efficient operation of the Deering power system in its present form. These include inoperability of the PLC-based automated switchgear, inoperability of the diesel generator water jacket heat recovery system, phase imbalances, and recent non-participation in the power cost equalization (PCE) program.
The first three issues are technical problems that will be addressed during wind turbine installation. With respect to the switchgear, it is not known at present why the power plant is operated in manual mode. This problem must be corrected though in order to accommodate wind turbines on the distribution system. Regarding heat recovery, presumably this involves temperature setpoint issues, but that has not been verified. It is recognized, however, that introducing wind power to Deering works best only when significant efficiency measures such as heat recovery are fully functional and operating efficiently. The phase imbalance problem is a bit complicated and related to seasonable load changes at the school and water plant. This may require a twice yearly load phase rebalancing effort to fully correct. Note that a technician is scheduled to visit Deering in September 2011 to asses and repair if possible problems with the heat recovery system and the PLC-based switchgear.
Wind Power System Configurations and Equipment
Wind-diesel power systems are categorized based on their average penetration levels, or the overall proportion of wind-generated electricity to the total amount of electric energy supplied to the system. Commonly used categories of wind-diesel penetration levels, are low penetration, medium penetration, and high penetration (diesels-off capable), as summarized in Table 5. The average wind penetration level is roughly equivalent to the overall amount of diesel fuel saved. In general, the higher the level of wind penetration that the system is designed for, the more complex and expensive a control system and demand-management strategy is required.