Wind energy developers installed 1.65 gigawatts of generation capacities in the United States during the third quarter of this year, though 2009 is shaping up to grow more slowly than 2008.

Overall, the developers have added over 5.8 gigawatts so far this year, said the American Wind Energy Association Tuesday. The third quarter saw more new capacities than the same period in 2008.

Cumulatively, the country has about 31.1 gigawatts of wind farms, which can generate enough power for 9 million homes, the AWEA said. The five states with the most wind farms, based on their cumulative capacities over the years, are Texas (8.8 gigawatts), Iowa (3.1 gigawatts), California (2.8 gigawatts), Minnesota (1.8 gigawatts) and Oregon (1.7 gigawatts).

The country installed about 8.55 gigawatts in 2008, and the AWEA is projecting somewhere between 6 gigawatts and 7 gigawatts for 2009.

But the wind market hasn't been immune to the global recession, despite efforts by the federal government and some states to provide tax breaks and grants to manufacturers and project developers.

The AWEA reported that wind turbine makers aren't churning out as many products as they did in 2008. The 5 gigawatts under construction now are roughly 38 percent lower than the over 8 gigawatts that were being built a year ago, the AWEA added.

Wind energy developers have been quite good at getting federal dollars, however. In a program to help renewable energy developers to offset 30 percent of each project's cost, wind companies have snagged billions while solar and other types won only a small share (see Treasury Grant's Big Winners: Wind Companies and Feds Issue $550.4M Green Energy Cash Grants).

Spain-based Iberdrola has been the biggest winner for this program so far.

Although Texas, Iowa and California have the most wind generation capacities, overall it was Arizona that saw the biggest growth during the third quarter. That was only because the state saw its first large-scale, 63-megawatt project during that period. Iberdrola built the wind farm to sell power to the Salt River Project.

Pennsylvania grew the second fastest by adding 29 percent more capacity in the third quarter. 

Image via Flickr/Creative Commons.