Electricity rates are set to rise across Ontario, although the hike will be tempered by a rebate program that kicked in during the new year, says the province's energy regulator.

The Ontario Energy Board announced Tuesday that ratepayers who are on the smart meter program will see rates rise by 0.8 cents per kilowatt hour during all time periods starting May 1. The average residential ratepayer — one who consumes about 800 kilowatt hours — would be faced with an increase of $3.80 a month, the OEB said.

Off-peak hours — during which electricity is priced more cheaply than during mid- and on-peak times — start two hours earlier at 7 p.m. instead of 9 p.m.

Local utilities have installed smart meters in homes across Ontario that allow them to measure exactly when electricity is being used in addition to how much is being consumed. They promote better resource use by billing customers extra for energy consumed during peak daytime hours.

Rebates kicked in Jan. 1

Customers still on the old pricing system, where electricity costs the same around the clock, face a larger increase.

The average person who does not have a smart meter faces a price hike of 6.1 per cent — around $6.12 a month, said the OEB.

Rates for people not on time-of-use are up 0.4 cents to 6.8 cents for the first 600 kilowatt hours each month, and up 0.5 cents to 7.9 cents for everything above 600 kWh.

Despite the increases, the Ontario Energy Board said consumer costs will remain at around the same level as they were last year, due to a 10 per cent rebate that kicked in Jan. 1. The Liberal government will stop issuing the rebates in five years.

The Liberal government has already warned electricity rates will jump 46 per cent over five years to pay for green energy projects and for badly needed upgrades to the system.

And while the province says the price increase is partially offset by the rebate, NDP Leader Andrea Horwath said it still equates to more money coming out of ratepayers' pockets.

“The government can kid itself all it wants and it can spin all it wants," said Horwath on Tuesday. "But the reality that people see when they open their bills is not a spin, it’s a fact and the fact is these bills are going up.”

With files from The Canadian Press