How Black Paint Can Reduce Bird Deaths From Wind Turbines

Wind turbines kill numerous birds, notably eagles and different raptors. The precise quantity is unknown, as a result of lots of the world’s wind farms don’t monitor chicken deaths. One mitigation concept to scale back these numbers—and assuage a political argument towards wind generators—is gaining traction: Paint one turbine blade black. Ecologist Roel May spoke with IEEE Spectrum about his 11-year study to scale back raptor deaths, and his shock on the lukewarm reactions from wind-turbine engineers.

How unhealthy are wind turbines for birds?

Roel Might: It relies upon quite a bit on the place you place the generators, and whether or not there’s breeding or foraging areas close by, and the species of birds. For those who put wind generators smack in the course of a susceptible inhabitants, the impact might be fairly massive. That’s what occurred in Norway on the island of Smøla, which is a scorching spot for white-tailed eagles. That’s the place we did our examine.

Why are eagles vulnerable to wind generators?

Might: Raptor species like eagles are superb at flying, however they don’t look straight forward; they give the impression of being down on the floor for prey. They like to make use of updrafts to soar, however updrafts are frequent close to ridges the place wind circumstances are good for generators. In order that’s a foul mixture.

Does the wind-turbine kind make a distinction?

Might: Bigger generators kill extra birds as a result of their blades take up extra space. However the place wind generators are smaller, there’s typically extra of them, so these wind farms could find yourself killing extra birds than farms with fewer, bigger generators, no less than onshore. Offshore wind farms are more durable to review: You’ll be able to’t rely the precise variety of birds that die as a result of you possibly can’t discover them; they fall into the ocean they usually’re gone. Some researchers are attempting to report collisions with bird radar, cameras, and different programs.

You discovered that portray one blade black resulted in a 70 % decline in chicken deaths. Ought to all wind farms be doing this?

Might: Our examine is one thing that needs to be repeated elsewhere as a result of there are seemingly site-specific and species-specific results. A bunch in the Netherlands painted blades and hasn’t seen a transparent impact. So we’d like extra research. There’s one examine getting in South Africa the place they painted a blade red, and a few others which arestarting in Wyoming, Italy, and Spain. The United Kingdom is planninga pilot project for offshore generators. However these research are onerous to do as a result of the operator has to get exemptions from laws to color the blades and rent licensed painters who can rappel up and down. And it takes numerous time. We collected knowledge on eagles in Smøla for seven years earlier than the blades had been painted. After we painted, we spent 4 extra years learning the consequences.

How did engineers reply to your examine?

Might: Lots of people from turbine producers requested if I had thought-about the technical implications of this. I hadn’t, as a result of I’m an ecologist, not an engineer. Apparently black blades will warmth up greater than white blades, which can trigger structural results. And the black paint is made with carbon, which might have an effect on the turbine’s efficiency when hit by lightning. Engineers don’t like that. So we have to overcome these disciplinary silos and work collectively to develop practical mitigation measures.

This text seems within the June 2025 print concern as “Roel Might.”