RESOURCES

Nuisance impacts like noise and shadow flicker are resolved through defined industry standards and regulations that have been applied for decades with long term monitoring. Some examples include decibel limits and shadow flicker hourly limits.

Shadow flicker generally occurs near sunrise and sunset and lasts just a few minutes. It is based on the angle of the sun in relation to the turbine and the person observing the effect. Before the turbine layout is final, studies are done to assess shadow flicker.

A 2012 study conducted by the Massachusetts Department of Environmental Protection found that shadow flicker from wind turbines does not pose a seizure risk due to the fact that shadow flicker from modern commercial wind turbines occurs at “flash” frequencies between 0.3 and 1 Hertz. Massachusetts Institute of Technology (MIT) researchers also concluded shadow flicker “would pose negligible risk to developing a photoepileptic seizure.”

As far as sound is concerned, wind turbines are generally quiet. When standing 1,000 feet away, the sound level of a wind turbine is similar to a refrigerator humming in the next room. Typically, two people can carry on a conversation at normal voice levels even while standing directly below a turbine.