Turbine troubles

Abstract

Nigel Williams reports on some of the emerging ecological problems with wind farms. Nigel Williams reports on some of the emerging ecological problems with wind farms. There is a push around the world to install renewable sources of energy in the face of global warming. Wind turbines have been particularly popular as a means of generating environmentally friendly, sustainable energy. But in the rush to build them in areas where they are best able to catch available wind, it is now increasingly clear that they may be causing damage to species occupying these areas. The first worries concerned birds, which are clearly vulnerable to the turbine blades if present in their flight paths, particularly at night. In Norway, where wind turbines have been constructed on Smola, a set of islands around 10 km off the north-west Norwegian coast, wind conditions are ideal and the turbines are well away from human habitation. But the area has one of the highest breeding densities of seabirds in the world and late last year the discovery of the bodies of four white-tailed sea eagles, Europe's largest eagle species which lives in the area, was attributed to collision with the turbines. And for the remaining birds, the turbines appear to be a turn-off. The birds are known to be deterred from nesting near new roads and buildings in Norway but appear keen to remain faithful to previous nesting sites. But Arne Follestad, a researcher at the Norwegian Institute for Nature Research, said: “Breeding results on Smola have been strikingly poor compared with 30 years before the wind farm was built, both on the site itself and in the remainder of the islands,” he said. “We are not confident that white-tailed eagles will adapt to the turbines and return to the wind farm to breed. As older birds die, we do not know if new birds will occupy nest sites here.” And while concern about the potential impact of new wind farms on some bird species is growing, research suggests the turbines may also be having an impact on bats. Reports of bat deaths linked with wind turbines have been recorded in many countries but researchers believe the structures may be revealing little-understood aspects of these animals' behaviour. For it appears that migrating bats are particularly vulnerable to wind turbines and may not use their echolocation mechanisms during these flights. With so little known about these migrations, wind farm planners face growing concerns in the location of new sites. Conservationists are keen that surveys of potential sites are carried out during both spring and autumn so that seasonal migrations can be detected to lessen potential ecological impacts.