Painting a blade black can dramatically reduce the number of birds killed by wind turbines by up to 70%. (Image Credit: May et al. ./Ecology and Evolution/Wiley Online Library)
The number of birds killed by wind turbines per year could be drastically reduced by painting one of the blades black. In a new study conducted at a wind farm in Norway, Smøla, researchers discovered that changing the color of a blade from white to black reduces birth deaths by up to 70 percent.
Currently, wind power is growing around the world, with over 60GW of new generating capacity installed in 2019. Wind power can be less costly than burning fossil fuels as long as they’re placed in the right area. Not only that, but most people prefer living next to a wind farm rather than any type of power plant, including solar.
Birds, bats and other flying fauna often fall victim to wind turbines when they fly into the white poles and blades. According to the US Fish and Wildlife Service, approximately 300,000 birds have died as a result of wind turbines in 2015. However, there is also a decline in bird deaths from wind turbines since the industry is shifting towards larger turbine blades that move more slowly.
Even though birds have incredible eyesight, they can’t see obstructions very well while flying. The white turbine blades can become blurred in the birds’ vision as they get closer to them. Scientists believe that painting the blades black can prevent them from becoming smeared in the birds’ vision, increasing their chances of spotting a rotating blade. As a result, this can give them enough time to avoid a collision.
At the wind farm in Smøla, the researchers discovered that four 70m tall turbines with three 40m-long blades killed six white-tailed eagles between 2006 and 2013. During those six years, 18 birds had died from flying into the blades of the four turbines. Five willow ptarmigans collided into the turbine towers rather than the blades.
In 2013, the four turbines had one blade painted black. After three years, the team discovered that only six birds were killed from flying into the turbine blades. By comparison, 18 bird deaths were recorded by the four wind turbines, a 71.9% drop in the annual fatality rate.
Bird deaths also varied depending on the season. There were fewer bird deaths from the painted wind turbines during spring and autumn. However, bird deaths were on the rise in the summer at the painted turbines. The researchers also suggest that because of the small number of turbines used in the study and the short duration, they will need to follow up this study with more research in Smøla and elsewhere.
Eventually, wind turbine manufacturers may paint turbines with a black blade before shipping them out. It’s more challenging to paint the blades black after they’ve been installed. The researchers had to wait a day when there wasn’t any wind, and afterward, someone climbed over 200-feet to paint the 131-foot long blades.
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