The Point Lepreau nuclear power plant went off-line in March 2008. Because PEI buys most of its power from New Brunswick, Maritime Electric, the Island's electrical utility, was then forced to find a temporary and more expensive source of power.
That replacement energy is costing Maritime Electric $2 million more each month.
It's a cost the utility will now have to bear for longer than it had hoped.
"We had heard of the delays prior to this so we had estimated it would be coming back online next summer," said utility president Fred O'Brien.
"It was definitely disappointing news to hearÂ… that it is going to be extended. Their current forecast is to February 2011."
O'Brien said those added costs will be passed on to customers, but the company is working out how to best do that.
"There will be additional costs in energy supply that will have to be recovered," he said.
"What we're trying to do is figure out the most appropriate way to recover those costs over an extended period of time."
Maritime Electric will be putting together a proposal for rate increases for the Island Regulatory and Appeals Commission, which sets electricity prices, in January.
O'Brien said it's too early to say how much more Islanders might have to pay.