Wind warms Alaskan hearths
by the CADDET US National Team

Brad Reeve with the AOC 15/50 wind turbine.
Photograph: Warren Gretz, NREL

Forty-two kilometres north of the Arctic Circle near the town of Kotzebue, 10 wind turbines produce enough electricity for 200 homes. Based on this experience from the first utility wind project in the state, wind energy developments may soon become a common part of the rural Alaskan landscape.

Background

The native people of Alaska live in small villages dispersed along rivers and the coastline. Kotzebue (population 3,500) serves as the economic, governmental and transportation centre for the 11 communities in the Northwest Arctic Borough, an area of roughly 92,000 km2. Kotzebue and most rural villages receive electricity produced by small, diesel-powered generators and distributed through local, isolated distribution lines. Diesel fuel is shipped 2,000 km to Kotzebue from southern Alaska, weather permitting. Like most Alaskan coastal settlements, the town is accessible by sea only in summer. As a result, large storage tanks are needed to hold enough diesel fuel for the long winter. Many of the tanks are 20 years old, and villages needing new tanks find that costs are now significantly higher because of new, stricter environmental regulations.

For the last two decades, the state of Alaska has subsidised the cost of diesel fuel to about 175 Eskimo villages at a cost of $15–17 million/year (where $ is the US dollar). The subsidy, responsible for bringing electricity to many of these villages for the first time in the 1980s, reduces electricity costs from the $0.20/kWh it costs the local utility to generate and distribute it, to about $0.12/kWh which the Kotzebue residents pay. Residents of smaller, outlying villages pay substantially more. However, the state has recently reorganised the subsidy, reducing payments and spreading them out over a larger base of population. In response, the utility Kotzebue Electric Association (KEA), a non-profit making co-operative, has been looking for ways to reduce electricity costs to its customers.

The solution

KEA began considering wind generation as a solution to lowering the region’s electricity costs in 1992. The first step was a formal resource assessment of the proposed site near the town. The next step was to find a suitable wind turbine. In the mid-1980s, the state of Alaska supported about 140 small wind projects, including three in Kotzebue, most of which eventually failed because manufacturers could not maintain the turbines in the rugged environment. A decision was then taken to develop the expertise locally for operating and maintaining the turbines.

Nearly 70 Alaskan villages, including Wales in the Northwest Alaskan Borough, are good candidates for wind energy development.

In 1995, KEA contacted the Atlantic Orient Corporation (AOC) which had developed a new turbine (the AOC 15/50) designed specifically for use in cold climates. AOC developed the turbine in the mid-1990s, partly with support from the US Department of Energy (US DOE) Turbine Development Programme.

By 1996, KEA had found a co-sponsor, the Alaska Division of Energy, to start the project. The following year, support was obtained from the US DOE and the Electric Power Research Institute for turbine verification and data collection (see CADDET Renewable Energy Newsletter 2/99, July 1999).

Local workers installed three turbines in September 1997 and, after two successful years of operation, erected seven more in May 1999. Site preparation and laying of foundations must take place in winter to protect the permafrost. With winter temperatures sometimes reaching -45°C in Kotzebue, Brad Reeve, KEA’s General Manager, said, “Hiring local people who are used to our conditions has helped keep the project moving through harsh weather.”

The wind turbine

The AOC 15/50 has been designed for low maintenance applications in remote, cold-weather climates. The turbine rests on a 24.4 m steel tower designed to withstand heavy ice loads and blizzard conditions. The rotor diameter is 15 m and the generator is rated at 66 kW continuous output. The three-bladed rotor has aerodynamic tip brakes, and there is an electrodynamic brake controlled through the generator for overspeed control. The blades spin downwind of the tower and employ stall regulation in high winds.

The turbine also contains an integrated drivetrain - built as a single unit - that is simpler and lighter than conventional drivetrains. This design reduces maintenance requirements by removing the need for couplings between the gearbox and generator.

Cost and performance

The cost of the three turbines installed in 1997 averaged $2,985/kW. The costs of the 1999 installation are not yet fully known; however, they are estimated to be about 25% lower. Given the output of the turbines in Kotzebue, KEA estimates the cost of energy is about $0.13/kWh, or about 13% less than the cost of unsubsidised generation from diesel. (Costs for electricity distribution and administration of the cooperative are separated from those for generation in this comparison.)

Turbine installation in Kotzebue in the winter of 1999.
Photograph: Kotzebue Electric Association

The output of all 10 turbines in 1999 totalled 470,000 kWh; wind speeds averaged 5.4 m/s. Kotzebue is reducing its yearly consumption of diesel fuel by 340,000–380,000 litres, which is about 6%.

The future

KEA is already sharing its experience with other utilities and Alaskan villages. It is working with the Chukchi Campus in Kotzebue to develop training programmes for local workers on how to install, operate and maintain wind turbines in remote villages throughout Alaska. The next wind project for KEA, scheduled for installation in 2000, is in the remote village of Wales (population 165). Here, wind turbines will supply 40% of the total electricity for the village.

“We believe the development of wind energy will create employment opportunities,” Brad Reeve said. “When we replace diesel fuel with wind, we save money that we keep in our communities.”

For more information contact the CADDET US National Team in Golden, Colorado.

The CADDET Renewable Energy Newsletter is a quarterly magazine published by  the CADDET Centre for Renewable Energy at ETSU, UK.

The articles published in the Newsletter reflect the opinions of the authors.  They do not necessarily reflect the official view of CADDET.

Enquiries concerning the Newsletter should be addressed to Pauline Toole, Editor, CADDET Centre for Renewable Energy, ETSU, Harwell, Oxfordshire OX11 0RA, United Kingdom. Tel: +44  1235 432968, Fax: +44 1235 433595.