Vesta’s Obstacle Collision Avoidance System (OCAS) eliminates turbine lighting pollution through using an on site radar system and passing aircraft as the on/off switch.
The on site low-energy radar continuously scans the enclosing area for nearby aircraft. Once one is detected the radar system begins to analyse vital information such as the altitude and heading of the craft to determine whether the turbine lighting needs to be switched on. If the lights are needed they will automatically be left on until the aircraft has safely passed over the turbines.
One benefit of this system is that it provides aviation surveillance all day everyday. The OCAS system has recently been fitted onto a Swedish wind turbine plant consisting of 27 Vestas turbines on the island of Gotland.
You can read more about the OCAS system here.