Driven by the success of its Green Power Switch program, the Tennessee Valley Authority (TVA) is requesting proposals for construction of 40-50 MW more wind in two steps over the next three years. The federal electric power and transmission agency, which provides power to more than 150 electric utilities in the southeastern US, wants to bring 20-25 MW on-line by October 2003 and to follow that with 20-30 MW more by October 2004. TVA already sells the output of three Vestas V47-660 turbines, installed by EnXco at a former mining site on Buffalo Mountain in Tennessee to 12 utilities through its green power program, says Gary Harris, manager of Green Power Switch. The green mix also includes solar photovoltaic and landfill gas power, which participating distribution utilities sell to retail customers in monthly blocks of 150 kWh for a $4 premium. Gil Francis of TVA says the agency will consider projects anywhere in the southeast, but the project must be able to connect directly to TVA's transmission or to a member's distribution system. The agency has no sites earmarked, but Francis says there is still room on Buffalo Mountain, although land has yet to be leased for more turbines. "The RFP is to determine the possibilities," he says. TVA will consider either a power purchase agreement with a developer or a turnkey operation in which the developer provides engineering and construction. Proposals are due September 28 with a decision due before the end of 2001.