Wind turbines have an unusual way of generating hot air. By drawing down warm air from the atmosphere above, they cause temperatures in their immediate surroundings to warm slightly.
Liming Zhou of the University at Albany, State University of New York and colleagues used land-surface temperature data gathered by NASA’s Terra and Aqua satellites to examine the effect.
The satellites give temperature measurements with a spatial resolution of roughly 1 square kilometre, which the team matched up with data from the US Federal Aviation Administration on the exact location of 2358 wind turbines in west-central Texas.
They found that the immediate surroundings of wind turbines were on average 0.5 °C warmer than the rest of the region. The study spanned 2003 to 2011, during which time the region saw a boost in the number of wind turbines, from 111 to 2358.
The warming was particularly pronounced at night. Zhou says the warming was caused primarily by vertical mixing of the air, rather than as a direct result of friction as air passes over the turbines’ blades: the movement of the turbines is mixing the cooler ground-level air with warmer air higher up.
More at the source article: http://www.newscientist.com/article/dn21759-wind-turbines-can-cause-localised-warming.html