The US installed nearly 7GW of new wind energy capacity in 2011, a 31 per cent increase on the previous year, according to industry figures.

New figures from the American Wind Energy Association (AWEA) show the US installed 6,810MW of new capacity last year, 3,444MW of which came in the fourth quarter as developers scrambled to qualify for a federal tax grant that expired at the end of the year.

California led the way for new installations, adding 921MW of capacity in 2011, followed by Illinois, Iowa, Minnesota and Oklahoma. Ohio was the fastest-growing wind power state in 2011 with 101MW installed, a growth rate of more than 900 per cent, while South Dakota and Iowa sourced the highest percentage of electricity from wind at 20 per cent.

“This shows what wind power is capable of: building new projects, powering local economies and creating jobs,” said Denise Bode, AWEA chief executive.

However, while the AWEA said 2012 looks set to be a strong year with a further 8,300MW currently under construction, the industry is warning that growth is likely to be substantially undermined if the government allows the Production Tax Credit (PTC) to expire at the end of this year.

A report by Navigant Consulting found half of wind industry jobs may be lost if the subsidy ends, while private investment will drop by nearly two-thirds from the current level of $16bn (£10.2bn) a year.

However, it said extending the PTC would allow the wind industry to grow to almost 100,000 jobs in just four years and stay on track towards supporting 500,000 jobs by 2030.

Legislation has been introduced in the House of Representatives to continue the PTC for four more years, garnering the support of 56 co-sponsors, including 13 Republicans.

Bode called on Congress to take action to pass the bill in the first quarter of this year or risk losing “a bright new manufacturing sector to foreign countries”.

“In hard economic times, we’re creating jobs and delivering clean, affordable electricity,” she said. “But we will lose all these consumer benefits and a brand new, growing manufacturing sector if Congress allows the PTC to expire. Businesses need certainty. That is why it is urgent that Congress extends the PTC now.”