Wind farms could raise temperatures

Posted by Emma Woollacott

Opponents of land-based wind farms have a new ally in the form of MIT. Researchers there say that, far from mitigating global warming, land-based wind turbines actually increase the temperature around them.

With the US Department of Energy expecting wind power to account for a fifth of the US’s electricity supply by 2030, the team used a climate model to analyze the effects of millions of wind turbines on the climate.

Such a massive deployment could indeed make a difference, they found - though not necessarily a welcome one.

Ron Prinn, TEPCO Professor of Atmospheric Science, and principal research scientist Chien Wang of the Department of Earth, Atmospheric and Planetary Sciences suggest that using wind turbines to meet 10 percent of global energy demand in 2100 could cause temperatures to rise by one degree Celsius in the regions on land where they're  installed.

The opposite holds true for wind turbines installed in water, though, with a predicted drop in temperaturs by one degree Celsius over those regions.

Prinn warned against interpreting the study as an argument against wind power, however.

"We’re not pessimistic about wind," he said. "We haven’t absolutely proven this effect, and we’d rather see that people do further research."

The team found that wind turbines on land reduced wind speed, particularly on the downwind side of the wind farms. This in turn reduced the strength of the turbulent motion and horizontal heat transport processes that move heat away from the Earth’s surface.

In contrast, when examining ocean-based wind farms, Prinn and Wang found that wind turbines cooled the surface by more than one degree Celsius. They said that these results are unreliable, however, as their simulation was not as accurate as it might be.

The study also found that the intermittency of wind power could require significant and costly backup options, such as natural gas-fired power plants.