Premier Darrell Dexter says the $6.8-billion deal between Nova Scotia and Newfoundland and Labrador power utilities will mean cleaner energy and more stability in the market. But it’s not clear exactly how much the deal will cost ratepayers.

Nova Scotia Power Inc. and Newfoundland’s Nalcor announced Thursday they have concluded negotiations on bringing energy to Nova Scotia from Lower Churchill Falls. The deal will bring a total of 500 megawatts a year into the province via an underwater cable. NSPI’s parent company, Emera, will pay the full cost of the cable — $1.2 billion — in exchange for 170 megawatts a year for 35 years.

The province hopes the steady energy source will help stabilize Nova Scotians’ power bills, as well as contribute to the goal of 40 per cent renewable energy by 2020.

Emera CEO Chris Huskilson said meeting the province’s emissions targets will require annual rate hikes of between two and three per cent, which includes the cost of the cable.