WINDROCK MOUNTAIN—A Tennessee Valley Authority program that allows customers to buy electricity produced by renewable energy sources has generated about one million megawatt-hours—enough to power 68,000 homes, officials said Monday.
TVA considers the innovative Green Power Switch program, the first of its kind in the Southeast when it started 13 years ago, a success story. TVA said the program has helped prevent more than 700,000 tons of carbon dioxide from being emitted into the atmosphere. That’s equal to keeping about 135,000 cars off the road for a year.
And it’s grown from 2,000 customers in 2000 to roughly 12,000 today. That could be because customers today are more aware of environmental concerns and have a greater understanding of their power sources, said Patty West, director of TVA’s Renewable Energy Program.
The Green Power Switch program allows customers to buy $4 blocks that ensure that 150 kilowatt-hours of electricity is generated by a renewable resource such as wind, solar, or biomass. Buying one block is equal to preventing the carbon dioxide emissions from more than 11 gallons of gasoline.
About 40 percent of the one million megawatt-hours produced through the Green Power Switch program so far has been come from the wind turbines at the Buffalo Mountain Wind Farm, which is located high on a ridgeline north of Oak Ridge and Oliver Springs. It’s TVA’s one wind power site and the first and only utility-scale wind site in the Southeast, said Ed Stephens, program manager of TVA’s Renewable Energy Program.
The Buffalo Mountain Wind Farm has 18 turbines. The three older ones, which are owned by the public utility, are now unused, their fate undetermined. The other 15 are owned by Invenergy, which sells the power to TVA.
Stephens said the farm, which generates the most electricity in the winter, produced 48 million killowatt-hours per year from 2005 to 2012, enough to power 3,400 typical homes.
TVA allowed reporters and officials to tour the site on Monday. It was, in part, a celebration of Green Power Switch and a chance to see one of its production sites at work.
“They’re a testimony to TVA’s dedication,” West said in brief comments at the base of one 256-foot-high turbine, its light gray, curved blades slicing through the sky with a “whoosh, whoosh” sound and arcing up to 390 feet above the ground, as high as a 20-story building.
Officials said renewable energy is more expensive than traditional energy, but TVA wants a balanced portfolio that is good for consumers and the environment.
They said wind turbines continue to evolve, with the technology increasing the amount of power each tower can generate and lowering the cost to produce a kilowatt. West and Stephens said wind turbines have gotten taller and the length of their blades has almost doubled.
The first three TVA-owned wind turbines at Buffalo Mountain were erected in 2001. They are smaller and are limited to generating 0.6 megawatts. The other 15 are capable of producing 1.8 megawatts. Newer models can produce up to six megawatts, West said.
Meanwhile, the production cost has dropped from $10,000 per kilowatt a decade ago to a range of $1,400 to $2,200 per kilowatt today.
West said TVA, which buys more than 1,500 megawatts of wind energy from the Midwest, continues to add renewable generation through green power providers, such as smaller 50 kilowatt solar power panels.
Visit the TVA Green Power Switch page for more information.
Note: This story was last updated at 10:39 p.m.