Researchers from the Norwegian Institute for Nature Research and Sweden’s Lake Ånnsjön Bird Observatory have discovered that by simply painting one of a wind turbine’s three blades in black, bird fatalities could be reduced by 70%.
The researchers used a Before-After-Control Impact approach, widely used to evaluate natural and human-induced disturbances in ecological settings, for their experiment which took place at the Smøla wind‐power plant in Norway, where a blade was painted in black on four turbines. They were then compared to four other unpainted turbines. After a ten-year monitoring period, researchers were able to say that the annual fatality rate was 70% lower for painted turbines than the unpainted ones.
The researchers believe that one black blade reduces the so-called motion smear, making the blades more visible to birds. The question of painting the blades is not as simple as it looks like: turbines must be turned off to be painted, and remain motionless while the paint dries. Costs could be reduced if the blades are painted before the turbines are built and switched on. In 2009 only, wind turbines killed approximately 46,000 birds, which is considerably low compared to nuclear power with a fatality rate ten times higher than wind, and to fossil-fueled power plants responsible for an estimated 24 million birds.