Updated: February 26, 2010 at 12:00 am
This week’s announcement that Rocky Wind Power would soon begin manufacturing small wind systems in Colorado Springs got a lot of attention for the 25 jobs the company will bring to the area and for the company’s status as the city’s first renewable-energy company.
You might be wondering, however, what exactly a “small wind system” is and whether you should consider bolting one to your roof.
The football-field-size wind turbines that Vestas is manufacturing and erecting on Colorado’s eastern plains are big wind — with each turbine able to power hundreds of homes. By contrast, a small wind system is usually sized to power a single home, providing about 5,000 watts of power (compared with the 3 megawatts of one of Vestas’ behemoths).
“For as little as $10,000, (people) can have free electricity for the rest of their lives,” said Steve Stultz, Rocky Wind’s chief financial officer.
Small wind turbines have become popular in recent years with farmers and ranchers, said Brodie Ayers, a renewable-energy specialist with the Rocky Mountain Farmers Union. Those turbines are typically located in windy areas and placed on towers 80 or more feet high.
Most zoning regulations prohibit anything like an 80-foot tower in a residential neighborhood. Rocky Wind instead uses a vertical-axis design that looks something like an overgrown egg beater and sits directly on a home’s rooftop.
“There’s nothing in our code that prevents you from installing one this afternoon,” said Dennis Hisey, El Paso County Commission chair.
Vertical-axis designs have been around for decades, said Ron Stimmell, small-wind manager for the American Wind Energy Association, a national industry group. But putting a turbine on a rooftop is too close to the ground to capture steady winds, even in windy areas, and past rooftop designs have struggled to live up to their potential, he said. The ground causes drag and slows wind speeds.
“I have yet to come across a rooftop installation that has performed as promised,” Stimmell said. “It’s in your economic interest to go as high as you can — you’ll get faster winds and more money in your pocket.”
However, Mona Newton, central regional representative for the Colorado Governor’s Energy Office, thinks rooftop wind systems show promise.
“I’ve gotten so many calls over the years from people who want to put up a wind turbine in their backyard,” she said. “I think that we’ll probably see quite a bit of acceptance of them.”
A 5,000-watt rooftop turbine from Rocky Wind costs about $16,000 (the company’s smallest system produces 1,800 watts and costs $10,000). Stultz said his company’s systems typically pay for themselves in 4 to 6 years (including a 30 percent federal tax credit), and will last for 30 years.
Just because you have a wind turbine doesn’t mean you can cut your power lines. Small systems tie into the electrical grid and, when the turbine produces more power than needed, the home’s electrical meter will actually run backward. When the wind dies, the utility provides power as usual.
“The advantages are that you’re producing your own power and you’re hedging your utility cost for the long term,” Newton said.
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