News in Science

Temperature changes linked to wind farms

Wind warming Scientists have found a link between wind farms and changes in local temperatures.

The study could help researchers better understand the impact of wind farms on local environments.

Scientists including Associate Professor Liming Zhou from the State University of New York, examined conditions around 2358 turbines at four Texas wind farms.

Writing in the journal Nature Climate Change, Zhou and colleagues report a temperature increase of up to 0.72°C per decade at wind farm locations, compared to nearby areas.

They also found the effect to be greater at night than during the day.

After discounting the impact of surface features such as vegetation, roads, albedo and surface structures, Zhou and colleagues concluded the temperature change is caused by air turbulence generated by the turbine rotor blades.

"Turbine rotors were modifying surface-atmosphere exchanges and the transfer of energy, momentum, mass and moisture within the atmosphere," the researchers write.

The findings are based on nine years of satellite data covering an area of central western Texas where some of the world's largest wind farms are located.

Their results match modelling studies showing wind farms can significantly affect local scale meteorology by increasing surface roughness, changing the stability of the atmospheric boundary layer and enhancing turbulence in the wake generated by rotor blades.

Significant impact

Zhou and colleagues say a large enough wind farm could even affect local and regional weather and climate.

They say the work draws attention to an important scientific issue that requires further investigation.

Climate scientist Professor Nigel Tapper, from Melbourne's Monash University, isn't surprised by the results.

"No matter what we do, any modification of the landscape will have an impact on air temperatures," says Tapper.

"The critical thing is that it's a local effect and one we need to understand."

"If you were to use solar panels rather than turbines you would still have an effect."

"The question is whether that local effect is offsetting the generation of power from coal fired power stations. Because fundamentally the impact of carbon dioxide emissions, is having a global effect rather than just a local one," says Tapper.

"I do believe in global warming and I believe we have to look at alternative energy. We need a portfolio of energy sources and wind farms will be one of them."

"It would be nice to do a similar study here, we would probably get a similar pattern," says Tapper.