Are wind farms good for the economy?

Centrica, which is raising 2.2 billion pounds ($3.26 billion) to help fund its proposed 25 percent stake in nuclear power generator British Energy, said it was "revisiting the economics of wind farms given rising raw material and credit costs."

The company, which hopes to start full operation of its new Lynn & Inner Dowsing wind farms off the coast of eastern England by the end of the year, has yet to approve investment for three more farms that it plans to build in the North Sea.

"The costs of building offshore wind are at a very high level," a Centrica spokesman told Reuters.

"This, coupled with the rising cost of credit given the economic situation, means we need to revisit all our numbers to ensure our projects are economic before we give them the go-ahead."