The contract, valued at over $241 million a year, includes the option to upgrade the three largest plants while saving about $2 million annually. Tuesday's vote was 8-1.
Newsday says the contract provides LIPA with access to 50 different National Grid generating units at 12 locations, including big steam plants at Northport, Port Jefferson and Island Park.
LIPA and supporters says the pact is needed in order to keep the lights on and meet regulatory capacity requirements. They say it also helps further the overhaul of plants to cleaner-burning power.
Environmentalists say the contract locks-in fossil-fuel plants and limits LIPA's ability to transition to cleaner energy.
Get Eyewitness News Delivered