New study finds that wind turbines could increase night-time temperatures (© Rural Learning Center/Creative Commons)
Wind farms can affect local weather and raise night-time temperatures on the ground, according to new research.
The study published in Nature Climate Change, used satellite data to show that land around newly constructed wind turbines in Texas warmed more than surrounding areas.
While results varied, averaged out the researchers found a warming of about 0.72°C per decade.
They believe this is caused by turbines bringing warmer air down to ground level.
The results were seen to be most prominent at night, when the ground becomes cooler than the air just above the surface.
“The result in the paper looks pretty solid to me,” said Professor Steven Sherwood, co-director of the Climate Change Research Centre at the University of New South Wales.
“And it shows that night-time temperatures went up by about a half a degree in the summer where the wind farm is. Daytime temperatures do not appear to be affected.
“This makes sense, since at night the ground becomes much cooler than the air just a few hundred metres above the surface, and the wind farms generate gentle turbulence near the ground that causes these to mix together, thus the ground doesn’t get quite as cool.
“The same strategy is commonly used by fruit growers (who fly helicopters over the orchards rather than windmills) to combat early morning frosts.”
The researchers suggest that turbines in other places might not result in the same temperature change as those seen in Texas.
The study area saw a major wind-farm programme in the middle of the last decade, with the number of installed windmills going from 111 in 2003 to 2325 in just six years.
The study examined data from NASA’s Aqua and Terra satellites that measured ground temperature across the region. They compared temperatures at the beginning and the end of the construction period.
While the whole region saw a rise in temperatures, this was more extreme around the wind farms.
See the full study here.