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 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 percent. That feels worth it to save some vital pollinators and pest controllers.
Techniques, technology
It’s now a legal requirement in the European Union to curb wind farms during times of peak bat activity: in the migration season, when wind speeds are low and temperatures are mild. New technology promises smart curtailment, taking local bat activity, temperatures and wind speeds into consideration, continuing to reduce bat fatalities while minimizing potential energy loss.
For 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 percent. Projects in other regions are testing the technique and other designs, including striped blades.
The threat posed to wildlife has been weaponized by clean-energy skeptics. Former U.S. president Donald Trump, for instance, mourned the death of “all the birds” killed by wind power on more than one occasion. But the truth is that the number of avian deaths from colliding with turbines pales in comparison to the 2.4 billion murdered every year by domestic cats.
Clean energy also kills far fewer animals than fossil-fuel power plants do. A 2012 study estimated that wind and nuclear energy kills between 0.3 and 0.4 birds per gigawatt-hour of electricity produced, compared with 5.2 birds killed per GWh of electricity from fossil-fuel projects.
Recently, as more wind projects are installed on the East Coast of the U.S., spurious connections have been made between the construction work and washed-up whales. Wind opponents claim that sonar-equipped exploration devices used to find wind farm sites are to blame, despite there being no evidence to back up their arguments. Never mind that wind developers have a legal obligation to ensure that there aren’t any marine mammals in the vicinity before using the sonar.
I don’t blame people for becoming wrapped up in these fears. A dead whale on a beach is a highly emotive symbol.
But let’s remember that turbines are far less destructive than the effects of untamed climate disasters. 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 is a Bloomberg Opinion columnist covering climate change.
