Just like ships and airplanes create a stream of turbulence that slows down vessels behind them, wind turbines chop up air and drag down the output of downstream turbines. But orienting a turbine slightly away from oncoming wind diverts its wake away from other turbines. And now by performing tests at a wind farm, researchers from Stanford University have shown that this “wake steering” scheme can boost the combined output of a group of turbines by up to 13 percent. Plus, it also smoothens the output and should reduce operation costs, the researchers say in Proceedings of the National Academy of Sciences.

Single wind turbines are the most efficient when they directly face oncoming wind. But things change when turbines are placed together on a farm. The wakes of slower, low-energy wind created behind turbines can cause significant power losses. At the Horns Rev offshore wind farm in Denmark, for instance, wake losses can reduce annual energy production by around 20 percent. “With wind farms increasing in size and quantity, wake losses are becoming an increasingly important factor in wind farm efficiency,” the researchers write in their paper.