The U.S. is fertile ground for small wind turbines, according to a report published this week.
The annual small wind report from the American Wind Energy Association (AWEA), released in conjunction with the organization's annual conference, shows that small-wind turbines installations have grown rapidly over the past three years and U.S. manufacturers are getting a foothold in the global market.
The installed capacity of the U.S. for small wind turbines--defined as under 100 kilowatts of capacity--grew by 15 percent last year compared to the year before, representing $82.4 million in sales and almost 10,000 new units capable of 20 megawatts of generation, according to the report (click for PDF).
Consumer demand and improved technology are helping fuel sales, but the most important factor was the passage in October 2008 of a 30 percent tax credit for renewable energy systems. About half of the total industry growth has happened in the last three years, said Ron Stimmel, the manager of legislative affairs and small systems at AWEA, in an interview earlier this month. There have been about 100,000 units sold since 1980.
In terms of products, there's a shift toward larger, grid-tied turbines. Even though total capacity grew, the number of units fell 6 percent, with the most growth in the 11 kilowatt to 100 kilowatt size range.
Microwind turbines, which can supply electricity for a home, have a capacity in the range of 2 kilowatts. For example, the Skystream 3.7 is rated at 2.4 kilowatts and, if there is a good wind resource, can supply a large portion of electricity for a single home or business. By contrast, a 100-kilowatt turbine, which looks like a smaller version of utility-scale turbines, could be used for community wind at a school or other municipal building.
The shift toward larger turbines reflects some of the challenges that small wind turbines have in capturing enough wind to provide a reasonable economic return or perform according to manufacturers' specifications.
Rooftop-mounted turbines have difficulties meeting expected performance because buildings cause wind turbulence, while turbines perform best with steady wind, according to the AWEA study. Solar is generally a better investments in cities, according to some wind developers.
In terms of businesses, about two-thirds of all small wind turbines sold in the world last year were made by U.S. manufacturers, according to the AWEA study. Ninety-five percent of small wind turbines installed in the U.S. came from U.S.-based companies. About $80 million of private equity went into wind manufacturers last year, according to AWEA.