The photo on the left shows Corey Zarecki (director of Gundersen Lutheran Envision Engineering and Operations) on top of the north tower nacelle on our Cashton, WI, wind project. He is standing next to the Federal Aviation Administration (FAA) light which is also shown in the right photo. Since wind turbines are tall structures it is necessary to notify the FAA when planning a project.
As part of the permitting process for a wind turbine project, the Federal Aviation Administration will conduct an aeronautical study to determine whether or not the turbine will present an obstruction hazard to aircraft navigation. If the location is determined not to constitute a hazard it is still required to have the turbine properly marked and lighted to enhance visibility for pilots and reduce the likelihood of a safety incident.
For sites with multiple turbines, the FAA lights are synchronized for all turbines so the entire project blinks at the same time. This makes the multiple turbine site less distracting to pilots. You may notice the synchronized FAA lights if you drive past or fly over a wind farm at night. During construction and prior to power being provided to the turbine, FAA lights can be powered from an on-site generator, solar or battery-powered FAA lights are also available.