According to Reuters "a new study Large wind farms might have a warming effect on the local climate, research in the United States showed on Sunday, casting a shadow over the long-term sustainability of wind power."

The results, published in the journal Nature Climate Change, showed a warming trend of up to 0.72 degrees Celsius per decade in areas over the farms, compared with nearby regions without the farms.

"We attribute this warming primarily to wind farms," the study said. The temperature change could be due to the effects of the energy expelled by farms and the movement and turbulence generated by turbine rotors, it said. 

More study is needed, but it would seem that this new technology might not be everything we have been told it would be.