Shadow flicker occurs when the blades of a turbine pass in front of the sun, creating moving shadows on the ground or structures.
Studies typically calculate the potential intensity of shadow flicker based on the location of wind turbines, their alignment, and their exposure on neighboring properties. Based on the results of these studies, project developers can use micro-siting to minimize a neighboring property’s exposure to shadow flicker.
Shadow flicker is not harmful to people. Questions have been raised regarding possible impacts on individuals with epilepsy. While epileptic seizures can be precipitated by light flashes in the range of five to 30 flashes per second, modern wind turbine blades do not rotate quickly enough to produce this effect.
In addition, the setback distances required to meet the county requirements (134 meters) will minimize any potential shadow flicker effects from the Na Pua Makani project to the neighboring community.