How bats are affected by wind turbines

Abstract: In this study a wind power park of five turbines, Gummaråsen, in the south west of Sweden have been investigated to find out if bats fly in the height of the rotor blades, what species are present and the abundance of bats, at the site. The result showed that no bats was flying close to the wind power turbine, at the height of the nacelle (machine housing) and rotor blades, but bats were present closer to the ground. On warm nights with no precipitation and low wind speed, bats were especially abundant at Gummaråsen. Bats are most abundant close to wind power turbines in late summer and early autumn, the conclusion of this study shows that bats were present at the site of Gummaråsen from September the 13th to October the 5th at ground level. At the height of the rotor blades no bats were detected from September the 12th to November the 21th. Further investigations performed earlier in the season, and investigations with automatic acoustic detectors, at each site, could give an additional picture of the bat abundance and species composition at Gummaråsen.