"You're seeing rates go up faster than they should," said NDP energy critic Peter Tabuns. "As long as the Liberals see a blank cheque as a parachute to get out of any tough spots, our bills are going to go up."
OPG said the rate increase, if approved by the Ontario Energy Board, would add about $5.36 each month to the bill for typical residential customers.
The reasons for the requested hike "include ensuring obligations for used nuclear fuel management and decommissioning costs are met," the government-owned utility said in a statement.
"As well, we will make investments in the plants over the next couple of years to set up the long-term operation of Darlington for 30 more years following refurbishment."
However, the government pointed out there's no guarantee the Energy Board will approve the rate hike for OPG, which has not had an increase in its rates since 2008.
OPG is currently paid 5.7 cents per kilowatt hour for nuclear generated electricity, while privately run Bruce Power is paid between 5.2 and 7.1 cents.
In 2011, the Energy Board not only rejected an OPG application to hike its base rate by 6.2 per cent, it actually lowered the rate by 0.8 per cent.
There will be public hearings on OPG's new application as it comes under review by the OEB before any decision is made. OPG wants to increase the rate Jan. 1, 2014.
Opponents of nuclear power say Ontario should shut down its aging reactors and abandon plans to refurbish nuclear generating stations.
A report by the Ontario Clean Air Alliance said that every nuclear project in the province's history has gone massively over budget, on average by 2.5 times.
If the OPG rate increase is approved, it will cost electricity consumers in the province $755 million a year, said Alliance spokesman Jack Gibbons.
"Cancelling the Darlington rebuild would save consumers more than $1.2 billion a year between 2020 and 2050," he said.
Ontario's Liberal government recently decided against building two new nuclear reactors, saying there was no need to spend more than $10 billion when the province doesn't need the electricity.
The NDP complained that decision also added to hydro bills because millions were spent in prepatory work on the new reactors that won't be built.
"They were irresponsible with the $1.1 billion spent to cancel gas plants in Oakville and Mississauga. They spent $180 million on a nuclear plant people knew wasn't going to go forward, and they've committed $1 billion to refurbishment when they don't even know the full costs of doing that work," said Tabuns. "They are not thinking about and caring about public money."
Ontario gets about 50 per cent of its electricity from nuclear generation. Energy Minister Bob Chiarelli said nuclear will likely fall to about the 47 per cent mark of the energy mix when the province's long-term energy plan is released later this year, but building new reactors won't be part of the strategy.