Wind farms cause local warming

Wind farms can increase temperatures in their surrounding areas, researchers working in Texas have discovered.

Wind turbines bring warmer air down to ground level, the scientists behind this study believe. In Texas, this has lead to rises in night time ground temperatures on the land near wind turbines. This information has now been published in the Nature Climate Change journal.

Researchers, however, do not believe results may be replicated in other locations and do not believe temperatures will continue to rise as a result of wind turbines.

“The estimate warming trend only applies to the study region and to the study period, and thus should not be extrapolated linearly into other regions or over longer periods,” said lead researcher, Liming Zhou.

“For a given wind farm, the warming effect would likely reach a limit rather than continue to increase in no new wind turbines are added.”

The area under observation was west-central Texas, where 2,214 new turbines have been added during the last six years, leading to a total of 2,325 turbines on the site.

The rising temperatures, recorded across the region, were most pronounced near the wind farms. The average warming, however, was only an equivalent of 0.72 degrees Centigrade per decade.

The scientists used Nasa’s satellites to measure ground temperatures throughout the period of increased wind farm construction in the area. This allowed comparisons between temperatures from the 2003 to 2005 period and those of the 2009 to 2011 period. Factors besides the wind farms, such as vegetation changes, were ruled out as not contributing to the increased temperatures that were revealed.

The scientists involved in the study believe at night, air above the ground level tends to be warmer than the ground, but turbines are stirring up the air and pushing some of the warmth back down.

This latest study agrees with an investigation into the effects of wind farms in 2010. This previous study, also conducted in the US, produced data on a single location and also showed wind turbines produced local warming.

The latest study, carried out by Dr Zhou, from the State University of New York in Albany, US, is now intended to be taken further.

“We are now expanding this approach to other wind farms, and building models to understand the physical processes and mechanisms driving the interactions of wind turbines and the atmospheric boundary layer near the surface.” Dr Zhou told BBC News.

 

Image: Wind turbines linked to local warming | Flickr http://www.uhi.ac.uk/ruralstudies