Installations in the final quarter of last year were 3.44GW, an improvement from 3.29GW in Q4 2010 but down from 4.11GW in the same period in 2009.

The US had 46.91GW of wind generation capacity by the end of 2011, enough to power 12 million average-sized American homes.

California led all states in adding wind capacity last year with 921.3MW. It was followed by Illinois at 692.5MW,