This term refers to the shadows cast by wind turbine blades as they rotate in front of the sun, similar to the shadow cast by a tree blowing in the wind. By positioning wind turbines at a carefully calculated angle and distance from dwellings, Apex can ensure that most homes in a project experience no shadowing at all. For those that do, shadowing will occur for no more than a few minutes per day, on average. Shadow flicker does not occur on cloudy or foggy days, or days when the wind is not blowing.

Some have wondered whether this flicker can cause seizures in photosensitive individuals. According to Epilepsy Foundation research, however, the rate at which wind turbine shadows “flicker” is far below the frequency associated with seizures.