Engineers at Iowa State University say they have begun studying how hills and valleys affect wind turbines' production efficiency.

Researchers are using miniature wind turbines to understand how hills, valleys and the placement of turbines affect the productivity of onshore wind farms, a university release said Tuesday.

While there is considerable data about offshore turbine performance over flat water, especially from European studies, there little information about the effects of uneven ground on wind turbines, researcher Hui Hu. Said.

Hu and his fellow researchers team have created the mini turbines and started running tests in Iowa State's $1.25 million Aerodynamic/Atmospheric Boundary Layer Wind and Gust Tunnel.

The researchers will use the tests to quantify the characteristics of surface winds over hilly terrains and determine the best placement of wind turbines and find the best design for large wind farms on such terrain.

"We want to work with the wind turbine industry to transfer some of our findings," Hu said. "We can help boost total energy capture. And we can lengthen the lifetimes of wind turbines, making them more efficient."