Small-scale windmills generate mixed reviews


Apr 5 - McClatchy-Tribune Regional News - Diana Bowley Bangor Daily News, Maine



Greg and Norma Dyer have a message for homeowners looking to harness wind power for a dependable source of electricity at low cost.

"Don't do it -- it doesn't pay off," Greg Dyer said recently. "Going green is not what it's cracked up to be."

The only thing the $15,000 Skystream 3.7 wind generator they had erected in June is good for, he said, is a Christmas tree. "I'm going to string lights on it, but it won't even run the Christmas lights I'm putting on it."

While the Dyers, who live on Route 7 in Dover-Foxcroft, are unhappy with their purchase, others say their windmills have generated what they expected, but they say location is the key.

 Joseph Nesin of Chester, who installed a 10-kilowatt Excel windmill atop a 140-foot tower on Pea Ridge Road, has produced more than 90 percent of the power he has needed for his approximately 2,000-square-foot veterinary office.

"It is doing exactly what we hoped it would do," Nesin said last month. "It was installed with the hope that it would provide somewhere between 80 to 90 percent of the power that I needed and it's actually performing higher than that." He said windmills have to be high enough in the air to get the wind stream and to avoid ground obstructions such as trees and buildings.

Mike Paradis of Green Earth Energy of Fort Kent, who sold and set up Nesin's windmill, said he also sells Skystream windmills, but he has found they are so new that they have some "initial issues." He said he has had to do repairs on most of his Skystream units as opposed to other units. Adequate tower heights are not supplied for the model, although they are still a good wind turbine, Paradis said.

Greg Dyer said he thought he had the location and height covered. He was told that his location was perfect for wind power. Rather than install the wind generator the typical 50 feet, he went 20 feet higher, figuring it would perform better in the somewhat wooded area surrounding his home.

"It was installed in June and we've had it for 10 months and it has put out an average of 5 kilowatts a day," Dyer said. In contrast, he said, "We use between 20 and 30 kilowatts a day, depending upon what we are running." Dyer said he was expecting the windmill would produce about half the electricity he and his wife use.

Debra Burdin, co-owner of Burdin's Renewable Energy of Dexter, the company that sold and installed Dyer's Skystream unit, said his windmill is producing well considering it's the least expensive model he could have bought from her. Burdin said the company has had no trouble with other Skystreams that it has installed in the region. Although she said the height of Dyer's pole is adequate, she suggested that the surrounding trees on Dyer's property might be blocking some of the wind.

While wind may be the fastest-growing electric energy source, home windmills aren't for everyone, according to Richard Hill, professor emeritus of mechanical engineering at the University of Maine.

"If you have a great deal of money, and you hate the public utility and if you think you live in a windy place, you'll be very disappointed when you put up a windmill," Hill said recently. "You may, however, be justified because you're interested in principle."

It was the principle that drew Dr. Steven Arnold of Range Road in Dover-Foxcroft to install a Skystream wind generator on a 53-foot pole. "I didn't really do it because I thought that it could replace buying electricity. I did it because it's clean," Arnold said recently. "And although it was quite expensive, I don't care one way or the other because I'm doing something good."

Arnold did say, however, that his windmill hasn't delivered more than 100 kilowatt-hours a month, although it was advertised as capable of generating 400 kilowatts-hours a month. "I can tell you it doesn't generate anywhere near that," he said. Arnold has found that the wind must blow at least 8 mph to get his windmill going.

"Initially, I wasn't really very happy with it, but the more I watch it spin, the more I know I'm doing something," Arnold said. "I would have liked it if it had made more, but I'm satisfied that it makes something."

Duke Leighton of Jennings Hill Road in Dexter said windmills aren't for everyone, but he's pleased with his purchase. His windmill, installed on an 80-foot pole in September 2009 by Burdin's Renewable Energy, generates about 20 to 30 kilowatt-hours a day. Leighton figures that during the windy months, the windmill has taken care of 50 percent to 60 percent of his electric bill.

Leighton said his location is so windy that it bent his flagpole. He said he spent about three years researching windmills before he took the plunge. "Wind is a funky thing -- it's like a river in the air," he said.

"It's a long-term project; it's not something that's going to be paid off in a year or two and I knew that," Leighton said of his $15,000 investment.

Hill said a small difference in average wind velocity makes a "great big" difference in how much a windmill can generate. How high a windmill is from the ground makes a difference because "the boundary layer effect on the ground slows down the wind," he said. There also are benefits associated with a larger-diameter wind-mill that has air foils and variable-pitch propellers, but that's essentially not realistic for a single user to justify the cost, he noted.

While Hill does not disparage wind power, he said it disturbs him that there are no supporting data for the larger wind turbines. No one has published the kilowatt-hours a year that are generated from Mars Hill and Kibby Mountain and compared those with the kilowatt-hours a year used in Maine and in New England, he said.

Evelyn DeFrees, spokesman for the Maine Public Utilities Commission, confirmed Monday that there are no figures available to the public about the kilowatt-hours generated from Mars Hill and Kibby Mountain because those operations are part of a competitive market. The PUC does not regulate the generated market; rather, it regulates only the transmission and distribution companies that move the power around, according to DeFrees.

Hill said a household on average uses about 100 watts per square meter, which includes electricity, heating and air conditioners.

"A wind farm, if you space the wind turbines out over the surface of the land, don't do any better than 3 watts per square meter," Hill said. If you make the windmills bigger, then they have to be spaced farther apart or they will interfere with one another. So the 3 watts per square meter are how much energy one can get out of a wind farm regardless of how big it is, he said. Offshore, a windmill might get up to 5 watts per square meter, but it's a "tremendous" surface area that has to be used. In addition, because the wind is so dilute, one would have to run a lot of wires to pull the energy together, he said.

"Whether you're talking the wind, the sun, the tide or whatever, these are all very dilute resources," Hill said. And for that very reason, he does not favor small wind turbines for homeowners. "If somebody asks me about the small scale, I say, 'Don't do it,'" he said.

The semiretired Dyers wished they had had that advice before they made their purchase. They have received a $4,000 state rebate for their windmill but aren't sure if they qualify for the 30 percent federal tax credit or cash grant.

"As it is right now, it's going to take us 55 years to pay this back before we get a nickel out it," Dyer said. During that time, the generator probably will have to be replaced two or three times, he said.

"Even if we do, down the road, get the federal money, we're still going to be 20 years before it pays off, which we won't live long enough to see," Dyer said.

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