Ontario’s electricity regulator says rates will go up May 1, but only marginally.

The Ontario Energy Board says prices for residential customers will increase by 0.1 per cent next month, adding about $1 to an average monthly electricity bill.

However, May 1 is also the date when the threshold for the lowest electricity price is lowered to 600 kilowatts from 1,000, which the board says will add another $3.60 to monthly bills.

Consumers will pay 5.7 cents per kilowatt hour for the first 600 hours, and 6.6 cents per hour for anything above that level.

The threshold for the lowest price rises back to 1,000 kilowatt hours Nov. 1, the next time the board sets electricity prices for the season.