January 13, 2007

More about extreme wind turbine noise

Farmers Weekly, 12 January 2007, p. 10, has an article about the Davies, a farming couple in Lincolnshire who have had to sleep away from their home 60 nights since September, because of the Deeping St Nicholas wind energy facility 3,000 feet from their home (see the excerpts from forum posts by "wiggyjane" posted yesterday). The article is accompanied by a sidebar:
The Wind Turbine Noise Working Group has been asked by the DTI [U.K. Department of Trade and Industry] to provide expert advice and guidance on issues surrounding what has become known as Amplitude Modulation of Aerodynamic Noise.

This is a low-frequency whooshing sound caused by the passage of air over turbine blades under certain atmospheric conditions. So far, little is known about the phenomenon or how it might be controlled.

Because amplitude modulation is difficult to predict, it is often not until a turbine is erected and fully working that the noise becomes evident. An acoustics expert, who asked not to be named, said that, although rare, it was becoming more common.

"The concern is that bigger, more modern turbines may be more prone to this problem," he told Farmers Weekly. ...

Because of the nature of sites required for wind farms, turbines are often in areas of low background noise which makes the noise of the blades all the more noticeable -- especially for rural residents used to peace and quiet.

Last month, noise worries contributed to the withdrawal of an application to build three turbines at Weston, Herfordshire. Noise has also been an issue for residents living near wind farms at Bears Down, North Cornwall and Askham, Cumbria.
wind power, wind energy, wind farms, wind turbines, environment, environmentalism