While small wind turbines (SWTs) have become increasingly common within the last decade, their impact on wildlife, especially bats, remains largely unknown. The R&D-project “Species conservation aspects at SWT sites” conducted an operational experiment by placing a mobile SWT at six sites of high bat activity, including roosts, commuting structures, and highly frequented hunting areas. Bat flight trajectories around the SWT were documented at each site using a specifically designed high-spatial-resolution 3D camera.
The results demonstrate that, despite the generally strong ability of bats to evade moving rotor blades, bat casualties at SWTs placed at sites of high bat activity can reach or exceed the current threshold levels set for large wind turbines. As SWTs provide less energy than large turbines, their negative impact on bats should be minimized by avoidance measures such as a bat-friendly site selection or curtailment algorithms.
Hartmann SA, Hochradel K, Greule S, Günther F, Luedtke B, Schauer-Weisshahn H, et al. (2021) Collision risk of bats with small wind turbines: Worst-case scenarios near roosts, commuting and hunting structures. PLoS ONE 16(6): e0253782. doi.org/10.1371/journal.pone.0253782