A Nevada wind farm has killed triple the number of bats allowed under an agreement with federal wildlife officials, yet the federal government has imposed no significant penalties.
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Located 260 miles northeast of Las Vegas, the 152-megawatt Spring Valley Wind Energy project supplies energy to approximately 40,000 homes. The project, however, has been forced to make changes in its operations after killing 566 bats in 2013, nearly three times the 169 allowed per year.

Operational changes included adjusting the “cut-in” speeds of the turbines on nights when bat activity is high, so the turbines start turning only when sustained winds reach about 11 mph instead of the normal cut-in speed of 7 mph.