Monday, June 15, 2009

isramart: Will climate change decrease the effectiveness of wind power?

isramart news:

New research shows that the very wind that many hope will turn alt-energy turbines may actually be dying. The reason, ironically: climate change, say the authors of a study that will be published this summer in Journal of Geophysical Research.

Both average and peak U.S. gusts have been on the decline for at least 30 years, particularly in the East and Midwest, reports the Associated Press, and fewer days—than in the past—have any breeze at all, according to lead study author, Sara Pryor, a professor of atmospheric science at Indiana University.

Winds are still blowing across the West at a good clip, but according to the readings (taken from wind-measuring stations), the Midwest has seen a 10 percent decrease over the past 10 years. "The stations bordering the Great Lakes do seem to have experienced the greatest changes," Pryor told the AP, explaining that with more water and less ice on the lakes (thanks to warming), winds move more slowly across the surface.

On a global scale, a cut in wind power makes sense with climate models, noted co-author Eugene Takle, a professor of atmospheric science at Iowa State University. As poles warm up, temperature—and likewise pressure—differences between the equator and poles will even out, which means less wind, the authors explained.

Although the research is based on years of data measurement, the authors admit that more rigorous study is needed to understand how climate change will impact winds—and wind power, a source that currently supplies about 1.5 percent of the globe's juice. Pryor also noted that it's possible changing landscapes around measurement equipment—from new buildings to growing trees—could skew the results over time.

Some climate scientists and wind energy proponents disagree with the findings, noting that models have so far shown no impact on wind speeds. But the director of Pennsylvania State University's Earth System Science Center, Michael Mann, told the AP that the research "demonstrates, rather conclusively in my mind, that average and peak wind speeds have decreased over the U.S. in recent decades."