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In a commercial first for the southeastern United States, Tennessee Valley Authority (TVA) has erected three 660 kW Vestas wind turbines on former coal mining land at Buffalo Mountain, near the town of Oliver Springs, and about ten miles from the US Department of Energy's Oak Ridge National Laboratory outside Knoxville, Tennessee. The Vestas V47-660 turbines are expected to produce some six million kWh of electricity a year -- enough to serve more than 400 typical Tennessee Valley households. The power will be sold through TVA's "Green Power Switch" program, which already uses electricity from solar photovoltaic panels on public buildings and will include power generated by landfill gas later this year.

Restoration and redevelopment of land abandoned after strip-mining of coal in the southern Appalachian mountains of east Tennessee could have advantages for wind power. "The strip miners basically cut the top off a mountain here," says Steve Smith of the Southern Alliance for Clean Energy in Knoxville. "The wind turbines certainly won't hurt the landscape at all."

California wind services company enXco developed the project for around $3.4 million. The reclaimed strip mine land is leased from Coal Creek Mining and Manufacturing of Knoxville for the 20-30 year duration of the project. The imported turbines were transported by road from the port of Charleston, South Carolina, and the US-made towers were sourced from Texas and Utah. Installation started in mid-August and was complete by early September, with commercial power production expected by mid-October.

Spreading the net

TVA's green power "market testing" phase began in April 2000 in association with 12 Tennessee public power companies. The program is expected to expand over the next two years to become available throughout the TVA region (Tennessee and parts of the surrounding states). About 8 MW of power is currently available in the form of 150 kWh "blocks," for which consumers are charged an extra $4.00.

Around 30,000 households are being targeted, along with commercial and industrial consumers, such as MacDonalds restaurants, Saturn car manufacturing and Kinko's photocopy shops. Oak Ridge National Laboratory has pledged to buy 0.5% of its electricity needs from the green power program. Knoxville Utilities Board, a local public power company, reports that 0.5% of its residential customers and 21 commercial consumers have signed up already, representing enough demand to take the entire annual output of the wind turbines.

TVA plans to increase the share of wind in green power generation. With average wind speeds of 7.5 m/s, and space for at least another 30-40 turbines at Buffalo Ridge, further wind farm development in Tennessee is likely soon. "This is a part of the country whose wind potential was previously ignored," says Smith. "But the ridges of the southern Appalachians may have space for as much as 800 MW of wind power on private land alone."