October 5, 2010
U.S.

Wind farms can change the weather

By Doyle Rice, usatoday.com 4 October 2010

Large wind farms can influence local air temperatures, according to a new study published today in the Proceedings of the National Academy of Sciences.

The data was collected over seven weeks in the summer of 1989 at the San Gorgonio wind farm near Palm Springs, Calif.

The study revealed that the wind farm caused the local area to cool down during the day and warm up at night, according to authors Somnath Baidya Roy and Justin J. Traiteur of the University of Illinois.

For instance, on one day of the study, the temperature at 1:00 p.m. upwind of the wind farm was about 100 degrees, but was about 93 degrees downwind, due to the effects of the windfarm.

The authors theorize that the turbulence generated by the turbine rotors, which can enhance the vertical mixing of warm and cold air, led to the temperature changes.

“To the best of our knowledge, this is the only meteorological field campaign conducted in an operational wind farm,” the authors write in the study. “The wind farm consisted of 23-meter-tall turbines with 8.5-meter-long rotor blades arranged in 41 rows that were spaced 120 m apart.”

Because many wind farms are located on agricultural land, the scientists say, local weather changes can affect crop productivity.

And what can be done? “The impacts of wind farms on local weather can be minimized by changing rotor design or by siting wind farms in regions with high natural turbulence,” the study found. “Using a 25-year-long climate dataset, we identified such regions in the world. Many of these regions, such as the Midwest and Great Plains in the United States, are also rich in wind resources, making them ideal candidates for low-impact wind farms.”

The authors add that “wind power is on the verge of explosive growth, most of it being in the industrial sector consisting of large wind farms.”

As USA TODAY reported last year, wind projects are being proposed near the Texas Gulf, the Atlantic Coast, the Great Plains and Upper Midwest.

President Obama said in April 2009 that he would allow turbines along the Atlantic as one way to help meet a goal by environmentalists and the industry of generating 20% of the nation’s electricity through wind by 2030. Currently about 1% of U.S. power comes from wind, according to the American Wind Energy Association.

URL to article:  https://www.wind-watch.org/news/2010/10/05/wind-farms-can-change-the-weather/