Wind turbines once had the reputation of being noisy and bothersome, but over the last decade improvements in turbine technology have been largely successful in reducing turbine noise. The main noise that is now associated with turbines is a “swooshing” noise made by the blades as they turn.  Although each individual’s sensitivity to noise varies, in most cases wind turbines are sited far enough away from buildings and public contact that they do not represent a serious noise nuisance.

According to the British Wind Energy Association, the audible noise produced by a wind farm is approximately 35-40 dB at a distance of 350 meters. For comparison, the noise level in a quiet bedroom is approximately 35 dB. At the perimeter of most wind farms, the noise associated with turbines is not sufficiently greater than ambient noise (ie. wind blowing over tree tops, rustling leaves, etc.). In most cases, the noise from road traffic is enough to drown out the sound of wind turbines/farms.

Although turbines are generally not known to cause noise nuisance under normal circumstances, recently some debate has arisen as to whether wind turbines create more noise at night and therefore pose sleep-related issues. Researchers are now in the process of investigating turbine night noise. Some preliminary research has found that turbine noise travels much farther during the night than during the day.

Because turbine noise is largely dependent on the size and type of turbine rather than on specific geographical issues, there are no particular issues relating to siting in the Western U.P.   The Michigan Wind Energy Working Group has developed a draft set of siting guidelines for siting wind turbines, The Michigan Wind Energy System Siting Guidelines, that does include recommendations related to sound.

Several useful websites regarding wind turbine noise are:

American Wind Energy Association: Turbine Noise Information http://www.awea.org/faq/tutorial/wwt_environment.html

Research Regarding Wind Turbine Noise at Night http://www.scoutmoor.com/News_and_Docs/Turbines_at_night.pdf