The US is set to overtake Germany as the world's biggest wind market in 2009 on the back of an investment boom which saw wind power generating capacity jump 45 per cent last year.

"Now is a pivotal moment for renewable energy in the United States," says Peter Duprey, chief executive of Acciona Energy North America, a subsidiary of the Spanish infrastructure group Acciona. "This is a real opportunity here for companies to stake a major claim in the market because there has been a pent-up demand."