Common Eider (Somateria Mollissima) Photograph Søren Krohn
© 1996 DWIA
Birds and Wind Turbines
Birds often collide with high voltage overhead lines, masts, poles, and windows of buildings. They are also killed by cars in the traffic.
Birds are seldom bothered by wind turbines, however. Radar studies from Tjaereborg in the western part of Denmark, where a 2 megawatt wind turbine with 60 metre rotor diameter is installed, show that birds - by day or night - tend to change their flight route some 100-200 metres before the turbine and pass above the turbine at a safe distance.
In Denmark there are several examples of birds (falcons) nesting in cages mounted on wind turbine towers.
The only known site with bird collision problems is located in the Altamont Pass in California. Even there, collisions are not common, but they are of extra concern because the species involved are protected by law.
A study from the Danish Ministry of the Environment says that power lines, including power lines leading to wind farms, are a much greater danger to birds than the wind turbines themselves.
Some birds get accustomed to wind turbines very quickly, others take a somewhat longer time. The possibilities of erecting wind farms next to bird sanctuaries therefore depend on the species in question. Migratory routes of birds will usually be taken into account when siting wind farms, although bird studies from Yukon, Canada, show that migratory birds do not collide with wind turbines (Canadian Wind Energy Association Conference, 1997).
© Copyright 1997-2003 Danish Wind Industry Association
Updated 10 May 2003