The number of home-based wind turbines is increasing rapidly. U.S. sales last year increased almost 80 percent, to more than 10,000 units. Generous federal incentives have helped, along with consumer interest in cleaner forms of electricity. However, the machines don't always work as advertised.
Farmers like Roddy Hanson, who have plenty of room on their land for the machines, are one of the big reasons for the boom in small wind turbines. Hanson lives in southwest Minnesota, and likes to do things himself.
"We're into producing our own energy if we can," Hanson said.
Two years ago, he spent over $50,000 on a wind turbine. The machine produces enough electricity to power his farm, plus he sells the surplus to his electric company. With no electric bill and the extra income from the power company, he figures the wind turbine generates $500 a month.
The wind turbine sits atop a 50-foot tower on Hanson's farm. The blades on his backyard turbine are stopped. Then a light breeze starts, and the machine begins spinning, gaining speed, producing a distinctive whoosh as its two blades slice through the air.
After about a minute though, the winds lighten, the blades slow down again and eventually stop.
"It was trying to get going and there wasn't quite enough wind today," Hanson said.
Nearby is an electric meter where Hanson can check to see how much electricity the turbine has produced. He'd like to see good news there every day, but depending on the wind, sometimes the tally is disappointing, and that's a common complaint.
Although production of small, home-based wind turbines is showing solid growth, there are disappointments. Most of them deal with expectations versus actual performance.
"It's doing OK, it's not producing quite as well as they'd promised," Hanson said.
He's making money on the machine, but not enough to pay it off as quickly as he'd hoped. Hanson says at the current rate, it will probably take 15 years to do that. Hanson said when he bought the machine in 2006, the estimate was 8 years. That estimate came from a sales representative for Next Generation Power Systems, the company which sold Hanson the machine. The sales rep no longer works for the company and has not returned MPR's request for an explanation.
Scott Doerfler is Next Generation's current sales director. He has not talked to the sales rep either, but concedes the rep may have over-promised.
"They might have been told that the production numbers for that turbine were higher than what the 50 foot tower can produce," Doerfler said.
Despite that, he said he believes long term, Hanson and others who bought the wind turbine will be satisfied with the product. Ian Woofenden, an editor at Home Power Magzine, said this sort of product performance dispute is common.
"This is a disease that we have in our industry," Woofenden said.
Woofenden said one step that will help cure the problem is a certification council that begins operation this year. It'll measure the electrical output of small wind turbines. Woofenden says this information will help consumers spot misleading statements in sales pitches for small wind turbines.
"We have people that expect these companies to be selling real products and giving good advice when they're not always," Woofenden said.
But Woofenden said over-promising sales representatives are not the only problem. He said some consumer disappointments are self-inflicted, and that they need to educate themselves better before they buy. He said choosing the right tower height for a wind turbine is crucial to future performance.
Woofenden said many turbines just aren't high enough to reach the most powerful winds. That's an issue Southwest Minnesota farmer Roddy Hanson can appreciate. There's a grove of trees and some buildings near his wind turbine, and sometimes he wonders if he should have invested in a higher tower.
"We could've gone another 20, maybe 40 feet," Hanson said. "And sometimes I kick around maybe I should have done that."
The added height though could easily have added a couple of thousand dollars or more to the cost of the project. It would have taken another series of calculations to determine whether the extra electricity generated paid for the added height.
It's a lot of work, but it may be exactly the type of precise figuring homeowners must do to insure a successful wind energy project.