The growth of wind energy Iowa in 2011 was outpaced only by growth in California and Illinois, according to the American Wind Energy Association.

A total of 646.7 megawatts of generating capacity and 282 new turbines were installed in the state during 2011, the trade association said. That was more installation activity than other states except California (921.3 megawatts) and Illinois (692.5 megawatts).

Iowa ranked second nationally behind California in total installed wind capacity at the end of 2011 for the second year.
Texas had more wind capacity than any other state, and California was third.

Nationally, the wind power industry installed 6,810 megawatts of capacity in 2011, up 31 percent from 2010. at the end of 2011.

Another 8,300 megawatts is under construction, the association reported. But the tax incentive that induces much of the wind development is set to expire in 2012 unless Congress extends it.

The association said the industry faces a recurrence of the boom-bust cycle it has seen in previous years when the tax credit was allowed to expired. Those years saw installations drop between 73 and 93 percent.

A megawatt of power can typically serve about 1,000 homes. The output of a wind turbine is well below half of its nameplate capacity because of variable wind speeds.