Marking has no effect on performance but does magnify the intrusiveness of wind turbines on the landscape. Marking The intent of obstruction marking is to make structures such as wind turbines more visible to aircraft. The flashing lights and red and white bands commonly seen on radio masts increase the contrast between the mast and its surroundings. Unfortunately this would also heighten the contrast between wind turbines and the sky, making them more visible not only to aircraft but to the public as well. Imagine the outcry from the Country Guardians if every wind turbine in Britain sported a flashing strobe light or from a Dutch landscape protection society if every wind turbine in the Netherlands were painted in such garish colors as the NedWinds off Medemblik.
Every country has such a requirement, though the actual limit varies.
Local authorities could still require navigation lights if the turbine was installed near an airport or a prominent flight path. The same limitation applies in the United States for towers below 200 feet. If the turbine and tower are deemed a navigational hazard, marking is required. Enercon is moving toward a standard 50 meter tower height for the North American market. Like others who've examined the issue, Enercon's Mark Haller expects that it will be sufficient to light perimeters turbines of a multi-turbine array in the United States, or it may be adequate to only mark corner turbines.