A new study offers promise that machine learning can help reduce bird deaths at wind farms.

A study published in the Journal of Applied Ecology tested an IdentiFlight International LLC optical system that tells wind farms when to idle specific turbines by detecting incoming birds whose species it can identify through machine learning. Researchers found that the system reduced golden eagle fatalities by 82% at the 200-MW Top of the World Windpower facility in Converse County, Wyo., relative to a nearby control site without the technology installed, the 99-MW Campbell Hill WindPower - Three Buttes wind farm. Duke Energy Corp. subsidiary Duke Energy Renewables Inc. has a 51% stake in both wind farms, and Manulife Financial Corp. subsidiary John Hancock Life Insurance Co. (USA) owns the remaining 49%.

The Peregrine Fund, a nonprofit that protects threatened and endangered birds, conducted the study with Western Ecosystems Technology, an environmental consulting firm, as well as the U.S. Geological Survey.

Wind turbines have accounted for an average of 328,000 bird deaths out of the more than 2.5 billion human-caused bird deaths annually in the U.S., according to the U.S. Fish and Wildlife Service.

"Wind power's impact is extremely small compared to other human-related sources of bird mortality, such as collisions with buildings and communications towers, vehicle strikes and habitat conversion," noted a statement from the American Wind Energy Association, citing that data. "Overall, wind [power] causes less than 0.01 percent of all human-related bird deaths in the United States."

For years, the industry has tried to deploy technologies to prevent bird deaths. Some companies sell pulse radar systems that can automatically deactivate turbines when birds of any species are detected. In 2018, the U.S. Energy Department announced a new technology for offshore wind farms developed by researchers at the Pacific Northwest National Laboratory that integrates stereo vision into detection software to better see the flight patterns of birds and bats.

Still, the prospect of bird deaths has slowed or halted the development of wind farms across the country, including the first proposed freshwater wind farm in the U.S., the 20.7-MW Icebreaker Wind Project (Lake Erie Offshore Wind Project) off the shores of Cleveland in Lake Erie. In 2019, the American Bird Conservancy and Ohio-based Black Swamp Bird Observatory sued the heads of three federal agencies over approvals of the project. The lawsuit is ongoing (American Bird Conservatory and Black Swamp Bird Observatory v. Dan Brouillette, Secretary U.S. Department of Energy, et al, 1:19-cv-03694-TJK).

Green vs. green

"These fatalities create a 'green versus green' conflict with wildlife that are impacted in the pursuit of reduced fossil fuel consumption," highlighting the conflict between wind power and raptor conservation, the new study said.

Such deaths can even create criminal liability for developers that run afoul of federal laws meant to protect wildlife. In 2013, Duke Energy pleaded guilty in U.S. District Court in Wyoming to violating the Migratory Bird Treaty Act in connection with the deaths of 14 golden eagles and 149 other protected species from 2009 to 2013 at its Wyoming wind farms. It was the first criminal conviction under the law for avian deaths at wind projects, the U.S. Justice Department said at the time. The North Carolina-based utility agreed to fines and said it would spend roughly $600,000 per year for a compliance plan aimed at preventing bird deaths at its commercial wind projects in Wyoming.

Duke Energy turned to the IdentiFlight system. The imaging system uses cameras and software to determine the distance, flight path and velocity of birds from up to a kilometer away. It classifies whether the incoming birds are a protected species, such as eagles, and alerts operators to shut down specific turbines to prevent collisions.

"The real advantage of our system is it's getting smarter each day," said Ben Quinn, senior vice president for sales at IdentiFlight. He said the system has been on the market for two years, and up to 100 units are now in operation across the world. The company had no control over the study's results, he said.

Researchers said that while the technology did not eliminate fatalities altogether, it "has the potential to lessen the conflict between wind energy and raptor conservation."

RES Americas Inc. launched IdentiFlight in 2016, and Boulder Imaging, Inc., a Colorado company, developed the system.