US wind farms face lack of fuel

Suzanne Goldenberg, US environment correspondent
guardian.co.uk, Wednesday 10 June 2009 19.59 BST

The great gusting winds of the Midwest may be dying, and with them hope for America's most promising source of green energy, according to a new report.
A study to be published in August in the Journal of Geophysical Research suggests average and peak winds may have been slowing across the Midwest and eastern states since 1973. The findings are preliminary, but measurements by wind towers raise the possibility of yet another side effect of global warming.
"We noted some periods in the past ... where there was a pretty substantial decrease in wind speed for 12 consecutive months," Eugene Takle of Iowa State University and one of the authors, told the Guardian. "We suspect it's some large scale influence we don't yet understand."
Areas of the Midwest have seen a 10% drop in wind speed over the decade. Some places have seen a jump in days where there was none at all. Takle said climate modelling suggested a further 10% dip may occur over the next 40 years. "Generally we expect there'll probably be a decline in speeds due to climate change."
The US is the world's largest producer of wind power; investment hit $17bn last year, and turbines are now a common sight. The American Wind Energy Association had no immediate comment, but a 10% fall in peak winds could translate into a 27% cut in energy, Takle said.
Gavin Schmidt, a climate scientist at Nasa, told the Guardian: "It's very preliminary. My feeling is that it's way too premature to be talking about the impact this makes."