8 Ways Wind Power Companies Are Trying to Stop Killing Birds and Bats

Wildlife researchers and industry are collaborating on new approaches—some proven, some experimental and even far-fetched.

| Mon Jan. 6, 2014 7:00 AM EST

This story originally appeared on Grist and is reproduced here as part of the Climate Desk initiative.

Hundreds of thousands of birds and bats are killed by wind turbines in the US each year, including some protected species such as the golden eagle and the Indiana bat. That's only a small fraction of the hundreds of millions killed by buildings, pesticides, fossil-fuel power plants, and other human causes, but it’s still worrying—especially as wind power is experiencing record growth.



The pressure is now on for wind energy companies to reduce bird and bat mortality. Lindsay North, outreach manager for the American Wind Energy Association, which lobbies for the industry, says wind developers are committed to "doing our best to try to have the lowest impact on birds."


"I am very optimistic we can make significant progress," said biologist Taber Allison, director of research at the American Wind Wildlife Institute, a nonprofit partnership of wind companies, scientists, and environmental organizations such as the National Audubon Society and the Sierra Club.


1. Smarter siting
It's all about location, location, location. The No. 1 way to prevent bird deaths is to do a better job choosing sites for wind energy development, said raptor researcher Richard Gerhardt: "It's an issue of where you put the turbines."


"Certainly as an industry we believe not every site is equal and not every site should be developed," said John Anderson, director of siting policy for AWEA. "It starts with desktop analysis of where the risk lies,” he said. "But you can't assess risks without on-the-ground boots analysis."

It would be difficult for wind developers to avoid eagle territory altogether. "The eagles love to fly where the wind is high and strong and they can soar over open country," said Frank B. Isaacs, golden eagle project manager for the Oregon Eagle Foundation. "And it is exactly the same places they want to put these wind farms."

But wind companies can at least avoid eagles' and hawks' migratory routes and known flight paths. For instance, wind farms could be set back from cliffs and sloping hills where eagles use an updraft to soar, Isaacs said.

2. Radar



3. GPS tracking


"They are listening, if you will, for condors," Allison said. "If they pick up a signal and it gets within this space, the company can say, 'We'll shut down this string of turbines.'"

bat boom box
A “boom box” prototype device designed to repel bats away from wind turbines, from Deaton Engineering. Ed Arnett/ Bat Conservation International

4. Ultrasonic acoustics

"There are two things that appear to be the most promising" when it comes to reducing bat deaths, said Chris Hein, wind energy program coordinator with Bat Conservation International.

The first of those is ultrasonic acoustic determent. Bat Conservation International has been collaborating with Deaton Engineering to design ultrasonic "boom boxes" that emit continuous high-frequency sounds, from 10 kHz to 100 kHz, intended to confuse bats’ echolocation to the point that they avoid the area.

"It essentially jams their radar, making it difficult to perceive sonar," Hein said. "That creates a disorientating atmosphere, and they don't want to be associated with that airspace. It doesn't harm the bat in any way. It would be like going into an extremely bright room that is so bright we wouldn't be able to navigate or see well."

Study results on this kind of technology have been largely inconclusive so far, but Hein believes that's because of the inconsistency of the devices that have been used to date. There are encouraging signs, he said. Tests of some ultrasonic acoustic equipment have found that it can halve the number of fatalities for certain species of bats.

"We still have a long way to go with that technology," Hein said. For one thing, it needs to be refined to work better in rain and high wind.

But he's hopeful that recent advances could lead to commercially deployable devices.

5. Leaving turbines off when wind speeds are low
The second strategy that has been shown to help reduce bat deaths is waiting longer to turn on the turbines, until wind speeds are higher. "Bats like to travel in very low-wind conditions," Hein said.


The question is whether this method is economically feasible. Anderson said the industry is "in the process" of evaluating this strategy.

"It does come at a cost to the electric company," Hein said. "But some of the early research shows the loss of revenue is not that much."


6. Painting turbines different colors
Some research has shown that migratory tree bats are attracted to turbines, but the reason isn't known, Allison said. One study found that they may associate the turbines with a body of water.



7. Designing new turbine shapes
Earlier designs were found to attract roosting birds, which would perch and nest inside the turbines' lattice-style structures, but newer designs discourage roosting.



8. Strike detection


The research could lead to commercial strike-detection equipment, said Jim Morgan, director of the North American Wind Research and Training Center at Mesalands. "If it works, it could be helpful for offshore wind," said Allison.

Morgan is hopeful that the research at Mesalands and elsewhere will eventually lead to a notable reduction in bird and bat mortality. "Man is good at solving problems when someone is willing to invest in the science," he said.



Allison believes there is also another motive: "They want to do it because they are conservation-mined, too. Many people in the wind industry work in the industry because they believe they're doing something to reduce the impacts of climate change, which many believe is the single biggest threat."