He says they're the last coal-burning plants in southern Ontario.
But there will be two coal units remaining in the province, which are supposed to close by the end of 2014.
The governing Liberals promised when they came to power nine years ago that they'd close all the plants, but have changed their deadlines several times.
McGuinty says his government will also expand the Greenbelt — land protected as green space — by adding the provincially owned Glenorchy lands in Oakville.
He says the Greenbelt will expand to the equivalent of about 8,000 square kilometres with the addition of the Oakville lands west of Toronto.