Ontario's summer hydro rate is now in effect, with an average household paying almost $6 a month more until the end of October.

If your home has a smart meter, or time-of-use pricing, your bill will go up about $4.

Peak times are also changing, with off-peak times now between 7 p.m. and 7 a.m.

The highest rates for electricity are between 11 a.m. and 5 p.m.

Ontario's opposition parties say the Liberal government's move into wind, solar and nuclear power are to blame for the increase.

Energy Minister Chris Bentley says the hike is mostly because of the cost to upgrade Ontario's electricity system.

The Ontario Energy Board says prices are rising as coal-fired power generation is replaced with natural gas, nuclear and renewable energy.

With files from The Canadian Press