The utility says it would have to stop its turbines from spinning at night for six months to a year to eliminate any risk to the little brown bats known to fly on the mountain.
Idling the turbines would cost the utility about $4 million a year in reduced power output.
The request comes as bat populations in the Northeast have been decimated by a fungal disease called white nose syndrome.
The draft permit says GMP will pay $18,000 a year to protect other bat colonies. The permit would still protect rare bats.