What Is Shadow Flicker?

Shadow flicker is the name given to a phenomenon caused when the sun is behind the turbine blades, as it rises or sets, casting a moving shadow over a small opening in a building, such as a window, creating a flickering effect within the building. This can only affect properties within a few hundred meters of the turbines.


A shadow flicker assessment forms part of every planning application Galetech submits. Current guidelines stipulate that shadow flicker must not exceed 30 hours per year, or 30 minutes a day. That’s why we design a turbine layout to avoid this phenomenon. Where it could occur, we install solar sensors on the top of the turbine, which will slow or shut down the turbine for a period of time, therefore mitigating the effect.


Thanks to technology and accurate calculations, which can pinpoint the time when shadow flicker could occur, turbines are shut down automatically to prevent shadow flicker.