Wind energy has long faced criticism for its impact on birds, especially large raptors that collide with spinning turbine blades. But a landmark study at Norway’s Smøla Wind Farm has found a remarkably simple and low-cost solution: painting a single rotor blade black.
By creating high visual contrast, the black blade disrupts the “motion smear” effect, where rapidly spinning white blades can appear almost invisible or blurred to birds. This simple change made the turbines far more noticeable, reducing overall bird fatalities by more than 70% compared to neighboring unpainted turbines. The benefit was especially pronounced for vulnerable species like the white-tailed eagle.
The study, conducted over many years using a rigorous Before-After-Control-Impact design, shows that this low-tech modification offers a practical way to help reconcile renewable energy expansion with wildlife protection.
While smart site selection away from migration routes remains the highest priority, painting one blade black is a promising, easily implemented mitigation measure that could be adopted more widely.
[May, R., Nygård, T., Falkdalen, U., Åström, J., Hamre, Ø., & Stokke, B. G. (2020). Paint it black: Efficacy of increased wind turbine rotor blade visibility to reduce avian fatalities. Ecology and Evolution, 10(16), 8927–8935. DOI: 10.1002/ece3.6592]