State police said it's happened multiple times since March.
The vandals pry open the ventilation gates on the door of the windmills' electrical compartments, then fire a gun at the components inside, causing significant damage and shutting down the turbines, troopers said.
Anyone with information is asked to call PSP Frackville at 610-378-4454 or submit a tip online.
Click here to follow Daily Voice Bristol and receive free news updates.