Windmills on the mountain? TVA project could boost tourism

By Kathy Helms-Hughes


   Residents from as far away as Jonesborough packed the Johnson County Courthouse Monday night to hear Tennessee Valley Authority representatives discuss details of a wind park and energy storage plant proposed for Mountain City.
   Stone Mountain, along with sites on the Cumberland Plateau in the vicinity of TVA's only operating wind park on Buffalo Mountain, currently are being considered for the project. The site selected will be chosen based on several factors including environmental impact, community acceptance, economics of the project related to development costs and the amount of wind on the site. The decision is expected to be announced sometime early next year.
   According to Gary Harris, manager for TVA's Green Power Switch program, Mountain Electric and Elizabethton Electric have expressed interest in the project.
   "The way the system works is the energy that is generated is put on the distribution system and then spread out so that everybody in the valley has the ability to take advantage of it. For example, if we had wind generation here in this area, people in Memphis could actually take advantage of the project and help you to pay for the project to make that resource available," Harris said.
   Cost for the wind portion for the 20 megawatt project is about $25 million. The energy storage facility is expected to cost about the same.
   The Green Power Switch program was initiated after results from a TVA poll showed that customers want a cleaner source of power.
   "We want to give customers a choice. This will be the first time customers have any type of choice in the power that they can buy," Harris said. "Eighty-four percent of the people that we polled when we were looking at this program said they would like to have a program such as this."
   Fifteen states currently have Green Power programs in operation. TVA operates 11 solar sites -- including projects at Dollywood, Cocke County High School and Ijams Nature Center in Knoxville -- and one wind turbine at Buffalo Mountain in Anderson County which is built on a reclaimed strip mine. It began operation Nov. 13, 2000.
   "There are people out there that will want to pay more because they know that if we don't make the change now, we're going to continue to see a deterioration of air quality," Harris said.
   "The way our program is structured is we sell it in what we call blocks. One block of Green Power Switch costs $4. That means that if you bought one block of your own every month, you would see a line item on your bill for $4. What that does is it gives you 150 kilowatt hours which equals about 4 percent of your monthly usage in kilowatt hours."
   Business customers pay on a rate schedule determined by their size.
   Bruce Bailey, president of AWS Scientific, a firm specializing in renewable energy technology, told those in attendance that one of the benefits from wind energy is there is no fuel costs.
   "The fuel is essentially free. There's little or no price risk or availability risk. It can provide economic benefits both at the local level and nationally."
   TVA's project at Buffalo Mountain put Tennessee on the map for wind power, Bailey said.
   "Why isn't there more wind power in the southeast? There isn't that much windy land area in the southeast. Most of the windy land area is in the Plains states. ... In Tennessee the number of places are few to choose from. They're mainly confined to the Cumberland Plateau and the Appalachian Mountains," he said.
   TVA initiated a wind measurement program last year and early this year at several sites in East Tennessee, including Stone Mountain, where winds have averaged 15-19 mph.
   "The typical wind turbine today is pretty different from what it was 20 years ago," Bailey said. "Some of you may recall the experimental wind turbine which was built near Boone, N.C. That was a federal government initiative to develop a new prototype. That project wasn't very successful. It was very different from the current generation of turbines ... Now they're highly reliable and very quiet and fit in quite well in a rural landscape. The Boone wind turbine happened to be a 2 megawatt wind system. Systems now over 20 years are getting up to that point. But that was sort of too big, too soon," he said.
   On a typical wind turbine, the blade span is 200-230 feet. The hub height of the tower rises to 213-262 feet with a total height reaching 325-374 feet.
   A wind system can generate electricity in speeds of 7-55 mph. A pivoting mechanism at the top of the tower turns the machine into the wind. Rotar speed ranges from 11 to 20 revolutions per minute.
   The foundation for a wind turbine ranges from 15 to 30 feet deep depending on soil conditions, while the width of the foundation is only 15 feet. To the greatest extent possible, existing roads are used to access the site.
   "Spacing tends to be an art and typically a science. Generally, wind turbines are spaced about two to three football fields apart (700 to 900 feet), mainly to minimize the effects of the interference of the wind of one turbine on another," Bailey said.
   Rick Allman, manager of TVA Energy Storage Operations, said one of the disadvantages of wind turbines is that the wind doesn't always blow at the speed needed to generate energy and it doesn't always blow at times of peak demand.
   "So one of the things that TVA proposes for this project is to install an energy storage technology. It's called Regenesys. It's a flow battery technology or regenerative fuel cell ... that will convert electrical energy into potential chemical energy," Allman said.
   The proposed facility would store energy until needed. TVA currently is installing a similar facility in Columbus, Miss.
   "It's basically the same size as proposed for this area. It will store about 120 megawatt hours of power and the way it's operated is it takes about 10 hours to be able to charge it. The facility takes up about 4 acres when completed. It's about 180 feet long by 60 feet wide by 40 feet high," he said.
   Chuck Nicholson of TVA's Environmental Policy and Planning staff gave an overview of the environmental impact.
   According to Nicholson, TVA is considering two sites on Stone Mountain: one at the north end near Bogg Gap and one at the south end near Logan's Gap.
   "We're talking about 13 or 14 turbines spaced out along the crest of the ridge," he said.
   "Wind turbines do make some noise. If you're standing right under the wind turbine right at the base of the tower when it is operating in a strong wind, the wind turbine produces about 100 decibels of noise. By comparison, typical background noise in this area if you're out in the woods during the day, the typical noise you hear when it's not real windy is 50-52 decibels," Nicholson said.
   "We're producing 100 decibels at the base of the turbine tower but the volume of that noise decreases very rapidly as you move away from the base. At a distance of about 600 feet, you're only hearing about 45 decibels," he said.
   On a clear day, the turbines would be visible from as far away as Elizabethton and Beech Mountain, N.C.
   Members of the audience, including area landowners, were generally receptive to the project. Some said it would generate tourism to the area because people from all over would want to visit this novel site.
   Others expressed concern that it would destroy the visual beauty of the ridgeline and that the noise would disturb the tranquility of the forest for those seeking to get away from it all.
   One Trade resident said, "It seems like the only negative comments I've heard is visual pollution. Maybe you all could take it back to your engineers and see if there's anything they can come up with as far as instead of having just a straight white concrete or steel pole holding these up, decorate them -- make them look like trees ..."