Wind energy can co-exist with wildlife

Wind power may be having a difficult year, but it’s still many times cheaper than oil or gas and remains a core piece of the energy-transition puzzle. A single rotation of a 260-meter-tall offshore turbine — General Electric Co.’s Haliade-X 13 MW, to be precise — can produce enough energy to power a household for more than two days, emitting no carbon or other pollutants.

Not everyone is a fan. NIMBYism is one of the biggest barriers to green energy installations, as local residents protest “view-ruining” turbines and new grid infrastructure. But one concern regularly crops up that I have some sympathy for: how wind farms affect wildlife. After all, we’re facing a biodiversity crisis, too. But where wind turbines are truly impacting animals, effective and often cheap mitigation measures are available.

Take bats. Around the world, our flying mammals are being taken out by wind turbines, either struck directly by a blade or suffering from barotrauma — damage to tissues from air pressure changes around turbines. One estimate puts annual bat fatalities somewhere between 600,000 and 900,000 in North America alone.

Research points to a simple solution. Rodrigo Medellin, an ecologist known as “the bat man of Mexico,” explained that, as a default, turbines typically start spinning at a wind speed of around three meters per second: a gentle breeze. But numerous studies have found that increasing the speed at which turbines become operational to six m/s reduces fatalities significantly. That’s likely because insects, which certain species love to feast on, can’t fly at those higher wind speeds, so bats don’t either.

And the cost in lost energy is negligible. If all turbines operated in that way, the annual energy losses would be just 1%. That feels worth it to save some vital pollinators and pest controllers.

In Africa and southern Europe, vultures have been struggling with wind turbines. Though these raptors have excellent eyesight to spot carrion on the ground, they have a tendency to miss the large white rotating towers that we’ve erected in their habitat. That’s due to a sizable blind spot which stops them seeing directly in front of them as they fly.

There’s plenty that can be done to help avoid collisions, such as clearing up carrion that attracts raptors to the area. But the best thing to do is just to stop the turbines. A study of 13 wind farms in Spain showed that selective stopping techniques – halting turbines when vultures fly too close – halved mortality rates with a reduction of just 0.07% in total energy production per year.

For other bird species, a simple paint job might suffice. A 2020 Norwegian study at a wind farm that was killing white-tailed eagles found painting one blade black reduced the mortality rate by 70%.

If you’re worried about the animals at a wind farm going up near you, don’t oppose the project, but do demand that the developer implements known techniques to minimize fatalities. We can have both wildlife and wind energy.

— Lara Williams

Bloomberg Opinion