How Black Paint Can Reduce Bird Deaths From Wind Turbines

Wind turbines kill plenty of birds, significantly eagles and different raptors. The precise quantity is unknown, as a result of lots of the world’s wind farms don’t monitor chook deaths. One mitigation thought 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 so much on the place you place the generators, and whether or not there’s breeding or foraging areas close by, and the species of birds. In case you put wind generators smack in the midst of a weak inhabitants, the impact might be fairly massive. That’s what occurred in Norway on the island of Smøla, which is a sizzling spot for white-tailed eagles. That’s the place we did our research.

Why are eagles vulnerable to wind generators?

Might: Raptor species like eagles are excellent 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 situations are good for generators. In order that’s a nasty mixture.

Does the wind-turbine sort 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 usually extra of them, so these wind farms could find yourself killing extra birds than farms with fewer, bigger generators, not less than onshore. Offshore wind farms are more durable to review: You possibly can’t depend the precise variety of birds that die as a result of you possibly can’t discover them; they fall into the ocean and so they’re gone. Some researchers try to file collisions with bird radar, cameras, and different techniques.

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

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

How did engineers reply to your research?

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 purposeful mitigation measures.

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