TORONTO - Ontario residents may be asked to ease off on their air conditioners this summer as the province heads into a hot summer with fewer nuclear units at the Pickering power plant.

Ontario's Independent Electricity System Operator says two units at the nuclear station were scheduled to come online this summer, but that has now been delayed until the fall.

Terry Scott of the IESO says no reason was given for the delay, but it means Ontario may have to import more energy when the temperatures start to soar, and consumers may be asked to conserve power.

He says the loss of the two units leaves Ontario short by 1,000 megawatts -- energy needed to power a city like Ottawa.

IESO chief operating officer Derek Cowbourne says Ontario imports power from its neighbours almost every day.

If the province experiences a heat wave or equipment problems, he says Ontario will just have to import more and appeal to consumers to conserve.