Close to one-third of the electricity produced in Ontario came from coal-fired generators this week — generators the new Liberal government in Ontario wants to shut down by 2007.

With half of the nuclear units in the province out of action, fossil fuels — predominantly coal — are being used to generate the province's power.

The strong dependence on coal makes it questionable whether the Liberals will be able to fulfil their pledge to close the coal stations by 2007, says energy consultant Julie Girvan.

"From an environmental perspective it sounds great," said Girvan, who frequently works for the Consumers Association of Canada.

"But until we know where the displaced power's going to come from, I don't know how they can do it."

Jack Gibbons, chair of the Ontario Clean Air Alliance, which has been pushing the province to close coal plants, still thinks the 2007 deadline for coal plants is a good one.

"It's an aggressive target, but it can be achieved."

The key is for the province to ask the Independent Electricity Market Operator to sign long-term contracts — say 20 years — with companies to build clean, gas-fired generators, Gibbons argued.

That will give investors the confidence to sink tens or even hundreds of millions of dollars into generators that burn clean natural gas.

During the peak demand period Wednesday, fossil fuel generating stations were churning out 7,895 megawatts of power, out of total production of 17,339 megawatts. Large water-powered stations contributed 5,070 megawatts, and nuclear plants 4,373 megawatts. (The figures don't include production from small-scale generators.)

Natural gas and oil fuelled some of the fossil production, but coal plants dominate the category.

Nuclear production is normally much higher, but the big Darlington nuclear station is out of service for several weeks for a scheduled safety inspection. In addition, the Bruce B and Pickering B nuclear plants each have a unit out of service.

One the plus side, the first unit to return to service at the Pickering A nuclear station — mothballed in 1997 — is approaching full power. And one unit of the Bruce A nuclear station, mothballed about the same time, produced limited power.

In their latest policy document, the Liberals have hedged their promise to shut down the coal plants by 2007.

"The plants will be removed from service only after we have a replacement up and running," it says.

Jan Carr of consulting firm Barker, Dunn and Rossi says it will be "extremely difficult" for the Liberals to meet their 2007 target, because it takes so long to plan and build generators.

"To replace that much generation in that short a time, people should be digging holes right now," he said. "That isn't happening. There isn't even a plan for it."

Nor will it be easy to replace coal plants with natural gas-burning generators, he said, since gas is in short supply.

Carr said the new government should not become so fixated on closing coal plants that it loses sight of the real objective.

"The objective is to have reasonable air quality," Carr said. Rushing to close coal plants might not be the most effective way to do that in the long haul.

Girvan notes that one way of decreasing reliance on coal is to cut demand — but the Liberals say they will maintain the price freeze on power prices for consumers and small businesses until 2006.

That does nothing to curb consumption, she said.