Since its formation in 2003, the Bats and Wind Energy Cooperative (BWEC) has been engaged in numerous research activities funded by DOE’s National Renewable Energy Laboratory, including studies assessing the impact of altering the cut-in-speed of wind turbines (the minimum wind speed at which wind turbines begin producing power), and the use of ultrasonic acoustic deterrents aimed at reducing impacts to bats at wind turbines. In 2013, BWEC published a synthesis of the operational mitigation studies, which demonstrated, at minimum, a 50% reduction in fatalities. BWEC has also evaluated the effectiveness of ultrasonic acoustic deterrents to reduce fatalities at wind turbines.