Wind farms, climate linked; Turbines blend air layers, report claims 

ABILENE – A study published Sunday in a national journal has linked wind farms to an increase in surface temperature in a portion of the Big Country.

The report does not suggest that wind farms are playing a role in climate change or contributing to a net warming of the air.

Rather, wind turbines appear to be blending warm and cool layers of air in the atmosphere, which may be leading to an increase in the temperature of the surface of the earth only in the vicinity of wind farms.

A professor in the Department of Atmospheric and Environmental Sciences at the State University of New York in Albany, N.Y., used satellite imagery to study the relationship between surface temperatures and wind farms from 2003 to 2011.

The results show a “significant warming trend” of up to 1.3 degrees, particularly at night, over a nine-year period relative to nearby regions that aren’t blanketed with wind turbines.

Satellite imagery was studied in an area roughly between Tuscola, Colorado City, Snyder and Anson, according to the report. The area, which contains about 2,360 wind turbines, was selected because it is home to four of the world’s largest wind farms.

“We are talking about a small and local effect on land surface temperature,” Liming Zhou, research associate professor with SUNY in Albany, said in an email. “The impact on surface air temperature (the variable used in weather reports) will be smaller.”

The study, led by Zhou, was published Sunday in the journal Nature Climate Change.

Zhou and his colleagues caution that the warming trend only applied to the geographic region studied and the results could not be extended to other wind farms.

Further, the warming effect for a given wind farm likely would reach a limit if no new wind turbines are added, meaning the surface temperature of the nearby earth would not continue to increase over time, according to the report.

“Very likely, the wind turbines do not create a net warming of the air and instead only redistribute the air’s heat near the surface, which is fundamentally different from the large-scale warming effect caused by increasing atmospheric concentrations of greenhouse gases,” according to a summary of the report provided by Zhou.

However, Zhou said it is important to further study the issue so researchers can understand the full impact of wind turbines on the environment, weather and climate.

“In terms of likely impacts on weather, if the wind farms are large enough, there might be an impact, but we don’t know,” Zhou said.

The study was touted as the “first observational evidence of wind farm impacts on land surface temperature using satellite data.”

The Big Country has been a major player as wind power expands globally.

The Horse Hollow Wind Farm was the largest in the world when it was constructed in Taylor and Nolan counties in 2006 with 421 turbines, said Steve Stengel, spokesman for NextEra Energy Resources.

Stengel said his company does not track temperatures around its wind farms, and company officials had not heard of any concerns about warming caused by turbines.

A meteorologist with the National Weather Service in San Angelo said she could not comment on Zhou’s study because she had not read it. The NWS does not have temperature sensors on the ground near wind farms.

Rusty Towell, chairman of the engineering and physics department at Abilene Christian University, said the study is interesting, though he noticed that the authors acknowledge their data may contain errors.

Ultimately, Big Country landowners and residents should not be concerned about the potential for surface warming, Towell said.

“It is hard to imagine that this will have any noticeable effect since natural variations are so bigger than this effect,” Towell said.