BAT WEEK: Protecting Bats During the Clean Energy Transition

While renewable power is critical to the reduction of emissions and the clean energy transition, it is important to mitigate environmental impacts and promote healthy ecosystems in the production of that energy. As we celebrate Bat Week 2023, EPRI is conducting a four-year project exploring opportunities to understand bat species interactions with offshore wind energy.

Bats are vital to the health of the world’s environment and economy. A single bat can eat up to its body’s weight in insects each night, which helps to protect food crops and forests from insect pests, saving farmers and forest managers billions of dollars each year. Bats also are important pollinators, vital for pollinating flowers and spreading seeds that grow into new plants and trees. Unfortunately, bats face numerous threats, including habitat loss, pesticide use, climate change, disease, and potential impacts from wind energy. 

Renewable energy solutions like offshore wind are seen as a key element in reducing global demand for fossil fuels. In 2022, wind power generated about 10 percent of U.S. energy and accounted for half of the electricity from renewables. However, according to the U.S. Geological Survey, thousands of bats are killed yearly in North America by collision with wind turbines, prompting the energy industry to explore technologies to lessen its impact on these vital creatures.  

The EPRI-led project team, funded by the Department of Energy in collaboration with the Bureau of Ocean Energy Management, includes Bat Conservation International (BCI), U.S. Geological Survey, Stantec, and Woods Hole Group working together to further the understanding of offshore bat spatial and temporal patterns. As part of the project, EPRI and its team engaged with Saildrone, a provider of ocean data using uncrewed surface vehicles (USVs), to test whether bat detectors could be used to collect bat calls on their USVs.  

Mapping bat spatial and temporal patterns can help energy companies avoid placing wind turbines in potentially risky areas. Offshore bat monitoring can be extremely difficult. To evaluate the risk of offshore wind energy development to bats, the team completed a first-of-its-kind project to study bats in a coastal environment using an ultrasonic microphone mounted on a Saildrone USV.

The goal was to demonstrate the viability of the platform as a tool for bat research and environmental impact assessments. The USV, with its ability to stay at sea for extended lengths of time with no impact on the marine ecosystem, was a unique approach. The team deployed USVs for a month during the fall migratory season to survey a known offshore migratory bat roost near South Farallon Island, an area approximately 25 nautical miles west of the Golden Gate Bridge in San Francisco. Equipped with an ultrasonic microphone, the USVs detected at least three species of bats and 830 individual bat calls. 

The USVs also collected meteorological and oceanographic data for a better understanding of the conditions that put bats more at risk for collisions, as well as environmental data for modeling potential offshore wind sites.

EPRI’s expertise in renewable generation and its focus on collaboration has supported the project team, helping test this new technology to fill in data gaps. Armed with this information, energy companies can better minimize the potential impacts of offshore wind energy on bat populations and continue to support the clean energy transition.