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Wind turbines visible from Interstate 70 in Bovina, CO, Friday, April 28, 2023. (Kathryn Scott, Special to The Colorado Sun)

Bats will get help avoiding wind turbines thanks to a $1 million grant from the Department of Energy, which announced Thursday it’s giving the Golden-based National Renewable Energy Lab funding to study how light from the enormous structures impacts bats and research ways to keep the mammals from flying into them. 

It’s all part of the DOE’s plan to lower costs and address barriers to deployment of wind energy in all its applications — offshore, land-based and distributed — across the country. NREL was among 15 projects chosen to receive grants totalling $27 million, and one of five dealing with bats in particular that received $7.5 million.  

When it comes to wind energy and wildlife, bats are a big concern, said Joy Page, Environmental Research Manager at the DOE’s Wind Energy Technologies Office. And a study by The Ecological Society of America confirms as much. 

Awareness of the impact of wind energy production on wildlife in the U.S. arose in the late 1980s when attention focused on turbine collision fatalities of raptors at one of the nation’s first large-scale wind energy facilities, in California, the study says. As wind energy development expanded across the country, research showed habitat impacts and fatalities among grassland songbirds and grouse species in the Great Plains and forest interior birds in the East were common. And after 2003, when wind energy had expanded further, studies showed a dramatic increase in fatalities when an estimated 1,400 to 4,000 bats died in a six-week period at the Mountaineer Wind Energy Center in West Virginia.

Colorado Parks and Wildlife officials say bats like the one pictured here are among the most mysterious land mammals, especially in Colorado. Eighteen species of bats make their home in the state, including the hoary bat, which researchers say is the bat most often killed in wind farms. The Department of Energy hopes to combat this with $7.5 million in funding to five organizations in states including Colorado to research ways to develop wind-farm bat-deterrent technology. (Colorado Parks and Wildlife photo)

Nine years later, the University of Colorado Denver reported that 600,000 bats were killed that year by wind energy turbines, “a serious blow to creatures who pollinate crops and help control flying insects.” And a recent NREL report showed the average wind energy related bat fatality is approximately four to seven bats per megawatt of installed wind energy capacity per year. 

Page said available data indicates that migratory tree-roosting bats, such as the eastern red bat, hoary bat and silver-haired bat, are most at risk in Colorado. Approximately one-third of all reported bat fatalities are hoary bats, which live everywhere from the state’s mountains to plains. And several studies indicate a high probability that wind energy is contributing to a population decline, Page said.  

NREL’s project will evaluate whether visual stimuli including bright aviation lights, silhouettes and light reflecting off a turbine’s surface attract bat species, assess the strength and scale of these effects and evaluate ways to decrease the attraction with things like changes in lighting and turbine surface reflectance.

Other DOE-funded projects include one testing whether lighting systems designed to alert aircraft to wind farms can minimize bat fatalities by turning on only when necessary; one project is using scientific studies about bat hearing, echolocation and ultrasonic sound propagation to develop and test more effective “playback sounds” to deter bats from turbines; and one is designed to determine whether ultraviolet light can be used to alter bats’ perception of turbines and thus prevent them from potentially associating these with their food source — the millions of flying bugs that congregate around lights and make great feeding grounds for nocturnal fliers, according to the National Institutes of Health.  


DOE said eagles and prairie grouse are also considered priority species when it comes to regulatory protection and/or vulnerability to wind energy impacts. But the U.S. Fish and Wildlife Service says migratory songbirds are the fliers most killed in wind turbines. They often migrate during the night at altitudes generally above rotor swept areas when weather conditions are favorable, but risk may be greatest during takeoff and landing where wind facilities abut stopover sites, the service says.

But bats are the current focus of research NREL coordinates through The Bats and Wind Energy Cooperative. That alliance of experts from government agencies, private industry, academic institutions and other organizations works on mitigating wind turbines’ impact on bats, while promoting the development of wind energy.

NREL’s headquarters are not far from the Golden cliffs, where some of Colorado’s 18 species of bats, which can eat more than 150 mosquitos in 15 minutes, hang out. 

Tracy Ross writes about the intersection of people and the natural world, industry, social justice and rural life from the perspective of someone who grew up in rural Idaho, lived in the Alaskan bush, reported in regions from Iran to Ecuador...