Bat radar

Large numbers of bats are killed by colliding with turbine blades or by experiencing sudden depressurisation immediately adjacent to the blade.

In an attempt to reduce this mortality rate, Aberdeen University scientists Barry Nicholls and Paul Racey, funded by the People's Trust for Endangered Species (PTES), have shown that there is a significant reduction in bat activity when a portable radar beam is directed at their foraging sites.

There are now 206 operational wind farms across the UK, with 2,381 turbines in use. Plans for another 444 sites means that the effects on the UK's bat population – not to mention birds – could be significant.

Although little work has been carried out in the UK, a six-week study on two American farms in 2004 recorded a total of more than 4,500 bat fatalities from collisions with the turbines.

Attempts at mitigating bird collisions with wind turbines have typically involved the use of visual stimuli to make the turbine blades more conspicuous.