Painting wind turbines black could cut bird deaths by 70 percent

Offshore wind farms are one of the most promising alternative energy sources ever invented. They also have a pretty pressing downside: they kill lots of birds.

New research from the Norwegian Institute for Nature Research poses a low-cost, painless solution to the problem. Researchers found that painting just one blade of the wind turbine black allowed birds to better see the rotating blades, thereby making it much easier for them to avoid a collision.

Wind turbines have become increasingly popular in the recent past as an effective means of ecologically friendly energy production, but bird fatalities — especially of rare or endangered species — are often listed as the biggest drawback to the technology. It’s not exactly an environmentally sound solution when it’s hurting other parts of the environment in the process. This research suggests we could nearly eliminate that problem, allowing wind power to be adopted on a wider scale.

Those poor birds — Birds have been crashing into turbines since the technology was first invented. According to Dr. Roel May, a senior researcher who worked extensively on the paper, somewhere between six and nine white-tailed eagles are killed every year at the Smøla wind farm alone.

The problem is that birds often assume open air space is just that: open. The researchers explain in their paper that so-called “passive” visual cues, like the motion created by a spinning wind turbine, can go completely undetected by birds that assume their path is clear. Until it’s too late, that is.

Black is the new black — The idea of painting rotor blades to make them more visible to birds isn’t at all new — the researchers cite work from scholar W. Hodos’ 2003 study suggesting the methodology. Until now, though, the theory has gone mostly untested.

At the time, Hodos tested seven different painting variations, including striping, staggering, and other colors of paint. His research found that painting one rotor plain black was the most promising effort, so this is where researchers started now. They tested the theory at the Smøla wind farm and concluded that the single black blade did indeed have the potential to reduce avian collisions by nearly 70 percent.

More to be done — This research is extremely promising. Painting a single rotor black is very easy and costs almost nothing, especially if done before the turbine has been installed.

But Dr. May and her associates know this is only the beginning of this line of research. The team wants to test other blade patterns, such as making the rotor tips red, to see if it would be equally effective. Then the real work begins: convincing developers and manufacturers to get on board and paint all their turbines.