Bats represent a substantial contribution to mammalian species diversity and ecosystem processes in North America, including their role in performing important economic service functions. The development and expansion of wind energy facilities is a key threat to bat populations in North America. Dead bats are being found underneath wind turbines across North America, and bat fatalities have been documented at almost all of the wind facilities at which thorough bat surveys have been conducted. The results suggest that thousands of bats may be killed annually at some wind facilities, and recent estimates suggest that hundreds of thousands of bats may be killed annually in the contiguous United States. Here, I use published bat fatality information to derive estimates of the number of bats killed at wind energy facilities in the contiguous United States in 2012 and conclude that over 600,000 bats may have died as a result of interactions with wind turbines.