Large wind farms can raise ground temperatures by around a degree Celsius, according to research carried out jointly by the University of Illinois and the State University of New York at Albany. The researchers analyzed nine years of temperature data taken from satellites over four of the largest wind farms in the world. They found that the turbines were pulling warm air from above, which led to an on-average 0.72-degree rise in nightly temperatures around wind farms when compared to surrounding areas.
As you'll likely remember from elementary science classes, warm air rises to be replaced by cooler air. The layering of air is typically at its most prevalent during the night, when conditions are at their least turbulent. The wind turbines, which at some farms average a height of 250 feet, create artificial turbulence which chops up the air, interrupting the natural pattern.
It's not yet known if the temperature change will have a knock-on effect
The team doesn't know if the higher temperatures are indicative of a microclimate which will affect rainfall, wind, and other weather conditions around the site. Atmospheric scientist Liming Zhou led the project, and was keen to point out that more work had to be done to ascertain what the knock-on effect of the rise in temperature is. "We don't know whether there is a change in weather due to the temperature change," said Zhou, but as wind farms become more widespread they "might have noticeable impacts on local-to-regional weather and climate." The team is now expanding its research to cover more farms, with the hope that it will help us to fully understand the ramifications of large-scale wind farming.