Project Overview
Chevak is located in western Alaska on the north bank of the Ninglikfak River, in the Yukon-Kuskokwim Delta. Chevak is classified as a second class city with a population of 938. Its location near the Bering Sea renders the area subject to heavy winds and rain. Temperatures range from -25 to 79 degrees Fahrenheit, with an average snowfall of 60 inches.
Objectives
Alaska Village Electric Cooperative (AVEC) optimized the use of heavy construction equipment and manpower by completing four major community infrastructure projects in Chevak in an approximately three year time span. The four projects were the wind turbines, the AVEC tank farm upgrades, community tank farm upgrades, and a new power plant.
The main objective of this project was to generate electricity from a local renewable resource to reduce the local dependency on fuel oil. The project included planning, design, construction and commissioning of 4 new 100 kW capacity wind turbines as well as a new, three-phase primary distribution line.
Construction was managed by STG, Inc., which also provided much of the heavy construction equipment and skilled labor. Local skilled and unskilled labor was also employed. Northern Power Systems manufactured the turbines and supplied the towers, and provided some
installation and commissioning assistance. Engineering of the foundations and secondary load system was accomplished by Hattenburg Dilley and Linnell, and additional system engineering was provided by AVEC staff.
Technology
Systems
Image Courtesy of Denali Commission
Turbines
4 Northern Power System (NPS) model “B” 100 kW turbine was the best suited model for Chevak’s wind class, a constructed generating capacity of 400 kW. Two of the turbines were 37 meters tall and two were 32 meters tall, meeting FAA clearance requirements. All are attached to steel beam foundations and driven steel piles. This foundation system was designed to counteract the overturning moment forces from wind and vibration. In order to preserve the integrity of the permafrost surrounding the foundations, thermosiphons were installed. The new primary distribution line connects the turbines to the new modular power plant. In 2009, the foundations were installed and towers and turbines were erected. The turbines were commissioned in November, 2009 and began producing significant power in February 2010. The secondary load system was commissioned in April, 2010.
Integration
Installation of a fiber optic communications link provides communication between the wind turbines and the control module in the new power plant, which allows the wind turbines to be either manually or automatically operated by the power plant and from AVEC headquarters in
Anchorage. The control module at the new power plant also houses electronic diesel engine controls and fully automated switchgear achieving a seamless integration of the energy from the wind turbines.
Boiler
In addition to these components, the system is fitted with a secondary load system comprised of a 265 kW electric water heater and related controls and switching relays, this system will absorb excess electrical energy during periods when wind turbine output exceeds the community
load and transfer the excess energy as heat to the AVEC power plant and potentially to other building(s).
Data and Analysis
Those wishing to learn more about the project can go here.
Funding
This project was funded by Denali Commission, Alaska Village Electric Cooperative (AVEC), and U.S. Department of Agriculture (USDA).
$565,025.00 of the funding came from the Denali Commission and $28,382.00 came from AVEC.
Links, Resources, and Documents
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