Wind of change

Researchers claim to have developed a new active damping system to cancel out the noise produced by mechanical components on wind turbines.

The technology, a collaboration between the

in Dresden and German industrial partners, uses piezo actuators and sensors to combat noise and actively adjust to changing frequencies.

The motion of rotor blades and vibrating cogwheels in a turbine's gearbox can emit clattering and whistling noises. These sounds can then be transmitted to the structure's tower, which acts as a loudspeaker and radiates the noise across a wide area.

For residents living near windfarms, this can sound like a constant hum. 'People find these monotone sounds particularly unpleasant, rather like the whining of a mosquito,' said André Illgen, Fraunhofer researcher.

According to the research centre, if the wind energy converters hum too loudly, local councils might demand that turbines only operate under partial load — which means they will not only rotate slower but also generate less electricity.