In a news release, the American Wind Energy Association (AWEA), said there were also more than 8,400 MW under construction.
The number of megawatts currently under construction was more than in any quarter since 2008 as the federal Production Tax Credit has driven as much as $20 billion a year in private investment, AWEA said.
AWEA said wind energy was now more affordable than ever, and new installations across the country were saving consumers money on their electric bills, as utilities lock in long-term favorable rates.
"This shows what we’re capable of: adding new, affordable electric generation," Denise Bode, CEO of AWEA, said in the statement.
"Traditional tax incentives are working. There’s a lot of business right now, people are employed, and manufacturers are looking to expand here in the U.S.," Bode added.
The AWEA statement said 2011 will "Finish strong, somewhere between the industry’s high point of 2009 and the recent dip in 2010 amid turmoil in federal tax policy."
AWEA said wind power — including incentives that AWEA said all forms of energy get — was now close in cost to all other energy sources, including shale gas.
However, uncertainty over government policies has many leading wind developers holding off on scheduling projects for 2013, AWEA said.
"We could lose all these consumer benefits and a brand new, growing manufacturing sector if Congress allows the Production Tax Credit to expire," Bode cautioned.
The Production Tax Credit provides an income tax credit of 2.2 cents per kilowatt hour for the production of electricity from utility scale turbines. The credit applies for the first 10 years of electricity production and is set to expire at the end of 2012. The Production Tax Credit has been renewed by Congress several times, and AWEA is working to get it renewed again.
The U.S. wind industry installed 1,204 MW of wind power during the third quarter of 2011 versus just 671 MW during the same period last year, a 79 percent increase, AWEA said.
Year-to-date installations of 3,360 MW exceed installations at this point in 2010 by 75 percent, AWEA said.
Colorado installed the most wind capacity in the third quarter with 501 MW.
California has the most megawatts under construction at more than 1,200 MW. Oregon has more than 800 MW and Oklahoma and Iowa both have over 700 MW.
The United States has 43,461 MW of wind capacity capable of supplying 10 million American homes, AWEA said.