Mexican free-tailed bats in flight. Ann Froschauer/US Fish and Wildlife Service
This story was originally published by Canary Media and is reproduced here as part of the Climate Desk collaboration.
It’s a known problem that onshore wind turbines kill bats. But it’s unclear whether the same issue applies to offshore wind installations—and the Trump administration just canceled groundbreaking research into the question.
Earlier this month, the nonprofit Electric Power Research Institute received a letter from the Department of Energy abruptly canceling its $1.6 million grant to study bat behavior in California waters earmarked for offshore wind development, a move that will hinder the nascent research effort. Christian Newman, EPRI’s program manager for the grant, said the organization is actively looking for other funding sources.
The researchers had been two years into a study of bats in the territory California plans to dot with floating offshore wind turbines over the coming decades. There’s so little information about how North American bats use the ocean environment that, in 2021, Newman and his colleagues determined in a peer-reviewed study that predicting the number of bats potentially killed by US offshore wind development was “impossible”—at least until more data rolled in.
The bat project is one of 351 individual Energy Department awards, totalling nearly $16 billion in funding, that in early October appeared on a leaked list of potential grant terminations. News reports have since verified the cancellations of some awards on that list, including more than $700 million for batteries and manufacturing, according to Politico’s E&E News. The cancellation of EPRI’s bat research grant has not previously been reported.
The news comes as the Trump administration defunds other research investigating offshore wind’s impact on wildlife. In recent weeks, the Interior Department scuttled two programs, totalling over $5 million, that were actively monitoring the movement of whales in East Coast waters where five commercial-scale wind projects are currently being built.
The West Coast bat study, awarded federal funding in 2022, supported researchers from multiple organizations, including Bat Conservation International. The US-based conservation group has been at the forefront of bat and wind-energy research for over two decades. Until recently, almost all of that work was devoted to onshore wind turbines.
“Wind energy is a really important component of our global energy transition. Unfortunately, wind turbines kill millions of bats globally every year,” said Winifred Frick, chief scientist at Bat Conservation International.
She contributed to a study last year that estimated onshore wind farms killed nearly 800,000 bats every year in just four countries that took annual tallies—Canada, Germany, the UK, and the United States
It’s logical to expect fewer bat deaths might result from wind turbines spinning out in the ocean compared to ones operating on land. After all, according to Frick, even scientists like herself assumed that most species simply do not spend much time at sea.
But, at least on the West Coast, researchers had never scientifically checked. In fact, EPRI was collecting first-of-its-kind information on how the Mexican free-tailed bat interacts with the ocean, deepening scientists’ understanding of the species overall. The EPRI team detected the bats vocalizing while flying over a dozen miles off the coast of Southern California last year, thanks to an acoustic listening device attached to a small sailing drone they launched. Before this study, no one knew that this common and widespread species spent any time at sea.
“One of the things that we’re learning is that there are more bats flying out in the [ocean] environment than we might have otherwise expected,” said Frick.
And that means more bat species are potentially threatened by California’s future offshore turbines than previously thought. Frick added that a greater understanding of which species spend time at sea and when can inform the design of solutions that better minimize fatalities from wind farms.
One solution is called curtailment. Frick described this approach as changing the “cut-in speed,” which is the minimum wind speed at which operators allow turbine blades to begin spinning at certain times of day or year.
The modification does not typically lead to significant changes in energy generation for onshore wind farms but can make a big difference for bats, she said. For example, preventing turbine blades from spinning until the wind reaches 5 meters per second can reduce fatalities among many species by 62 percent on average, according to a study released last year by Frick and her colleagues.
Determining the best curtailment solutions for offshore wind turbines and North American bat species is still a work in progress. Energy Department-funded studies, like the EPRI effort, were seen as critical to determining which bat-saving modifications would work best for California’s unique vision to build floating turbines.
Frick called the grant’s termination “devastating” because the team may not get to finish the study. In the meantime, researchers are retrieving bat listening devices from spots along the West Coast.
Bat Conservation International continues its efforts to minimize bat deaths from turbines on land. It received a $2.4 million grant from the Energy Department last year to assess how new technology might help. That award also appeared on the leaked list of 351 DOE projects seemingly slated for cancellation. But, according to Frick, the federal government has yet to cut that research—“it’s not officially terminated”—and she remains optimistic that it might endure.
