Can shadow flicker from wind turbines trigger seizures in people with epilepsy?

No.

The flicker of a wind turbine shadow is far below the minimum frequency required to trigger photosensitive epilepsy.

The North Dakota News Cooperative is partnering with Gigafact to produce timely Fact Briefs, which are quick, evidence-based fact checks about trending claims relevant to North Dakota.

A wind turbine is said to produce a “shadow flicker” when its rotating blades pass between the sun and an observer, creating a repeating pattern of light and shadow.

Photosensitive epilepsy is triggered at frequencies of 3 Hz or higher, or 3 flashes of light per second. Wind turbines generate flicker frequencies of 0.5 to 1 Hz, well below the known minimum trigger frequency.

One study calculated that a typical three-blade turbine would need to operate at 60 rotations per minute (rpm) to potentially trigger photosensitive epilepsy. Modern turbines operate at maximum speeds of only 15 to 17 rpm.

Research and public health surveys have not established a phenomenon of wind turbine-induced photosensitive seizures.

This fact brief is responsive to conversations such as this one.

This fact brief was originally published by our Gigafact partner, Skeptical Science.

About Fact Briefs:

Fact Briefs are bite-sized, well-sourced explanations that offer clear "yes" or "no" answers to questions, confusions, and unsupported claims circulating online. They rely on publicly available data and documents, often from the original source. Fact Briefs are written and published by newsrooms in the Gigafact network. Each brief is limited to 150 words or fewer and is not intended to provide an in-depth analysis, but rather to deliver concise, definitive answers grounded in verified information.

Sources

U.S. Department of Energy Shadow Flicker
Massachusetts Department of Environmental Protection Wind Turbine Health Impact Study: Report of Independent Expert Panel
Front Public Health Journal Wind Turbines and Human Health
IEEE Environment Impact Assessment for New Wind Farm Developments in Ukraine
Energy Reports Journal Occupational health hazards and risks in the wind industry
Columbia Law School Sabin Center for Climate Change Law Rebutting 33 False Claims About Solar, Wind, and Electric Vehicles

The North Dakota News Cooperative is a nonprofit news organization providing reliable and independent reporting on issues and events that impact the lives of North Dakotans. The organization increases the public’s access to quality journalism and advances news literacy across the state. For more information about NDNC or to make a charitable contribution, please visit newscoopnd.org. Send comments, suggestions or tips to michael@newscoopnd.org. Follow us on Twitter: https://twitter.com/NDNewsCoop.