The result, after years of freezes and caps, was an artificially low price for electricity in the province, which acted as a disincentive for homeowners and businesses to invest in energy efficiency and conservation projects.
When the current Liberal regime came to office in 2003, however, one of its first actions was to lift the freeze imposed by the previous Conservative government on electricity rates for homeowners and small businesses.
The Liberals took some heat for this move, not least because it represented another one of their broken promises.
But the public backlash was relatively subdued, which suggested the province had entered a new, more mature era where people were prepared to pay the real cost of electricity.
But just in case, the Liberals kept one foot firmly on the brake, with a hard cap on rates charged by government-owned Ontario Power Generation (OPG) for electricity from its "heritage assets", the nuclear plants and major hydro facilities such as Niagara Falls.
That cap comes off on April 1, 2008, however, and now the province's tolerance for higher electricity rates is really going to be put to the test, as OPG served notice late last week that it will be seeking a 14-per-cent hike.
As OPG sees it, the rate hike is required to bring in the additional revenue (over $400 million a year) needed for reinvestment in essential new nuclear and hydro projects in order to keep the lights on in the province.
Besides, as OPG noted in its press release, the rate hike will translate into an increase of just $3.50 a month in the electricity bill for the average householder.
The government was silent on the matter. "The intention is just (to) leave it with the OEB," said a spokesperson for Energy Minister Gerry Phillips.
The OEB is the Ontario Energy Board, the regulatory body that must approve electricity rate hikes. It will hold hearings on OPG's application next year.
NDP Leader Howard Hampton was not shy about reacting immediately to the proposed rate hike, however.
He noted that it would have a negative impact on the province's forestry and manufacturing sectors, already severely damaged by the rising value of the Canadian dollar.
"It's going to kill a lot of jobs and create a lot of hardship," said Hampton.
On the other side of the argument are the Green party and environmentalists, who point to much higher rates in jurisdictions like New York (which charges consumers more than twice as much as Ontario for electricity), California and Massachusetts. Not coincidentally, these places are admired for their conservation efforts.
"We've been subsidizing electricity rates in Ontario for 100 years and it's no longer appropriate if we want to create a culture of conservation in the province," says Jack Gibbons of the Clean Air Alliance.
There, then, the battle lines on electricity rates are drawn, between producers and environmentalists on one side and consumers and industry on the other.
The government, caught in between, is eventually going to have to come down on one side or the other.