Prior to the economic downturn, wind turbines were in high demand, but in the past 18 months wind energy has lost some momentum despite the nation’s continued push for “green” energy sources.

In late July, the American Wind Energy Association reported that only 700 megawatts of wind power was installed in the United States in the first half of 2010. That’s 71 percent fewer wind towers than in the first half of 2009 and 57 percent fewer than in the first half of 2008. New installations for full-year 2010 will likely be 25 to 45 percent below last year, the group estimates.

Construction on a number of wind-power projects will at least be started this year to take advantage of the federal convertible tax credit that is due to expire. Currently there are about 5,500 megawatts in the pipeline. Next year, however, AWEA predicts a dramatic decline “as there is no demand beyond the present coasting momentum” without new federal government policy to promote wind farm demand.

“Strong federal policy supporting the U.S. wind energy industry has never been more important,” says Denise Bode, AWEA’s chief executive officer. “We have a historic opportunity to build a major new manufacturing industry. Without strong supportive policy, like a national renewable electricity standard to spur demand, investment and jobs, manufacturing facilities will go idle.”

Federal stimulus money from the American Recovery & Reinvestment Act has helped to bring some wind power projects already in the pipeline to the finish line, adds Bode. “However, power purchase agreements—the locomotive that drives the project pipeline—are difficult to obtain today given the drop in overall electricity demand, lower natural gas prices and the absence of a clear national renewable energy policy.”

AWEA says a renewable electricity standard would prompt utilities to buy wind power and stimulate demand again. As proposed in the American Clean Energy and Leadership Act of 2009, which got the nod of the Senate Energy and National Resources Committee last summer, a national renewable electricity standard would require that 15 percent of the United States’ energy be produced from renewable sources, such as wind, solar and biomass, by 2020. However, the scaled down energy bill recently introduced by Sen. Harry Reid (D-Nev.) did not include a renewable electricity standard, but rather focused on the cleanup of the oil spill in the Gulf of Mexico and measures for improving U.S. energy efficiency.