John Spears
Toronto Star
September 26, 2003

Ontario’s power supply is improving, but the province still needs more electricity generating capacity, says the agency that oversees Ontario’s electricity system.

Even if mothballed nuclear plants return to service as expected over the coming months, the province will be short of the power needed to provide for the normal safety margins this fall, says the Independent Electricity Market Operator (IMO).

When Ontario is short of power, it must import supplies from its neighbours.

The IMO’s analysis is contained in its 18-month forecast, which is updated every three months. The latest forecast notes that one unit of the Pickering A nuclear station has returned to service after being mothballed in 1997. Two units of the Bruce A nuclear station are due to return to service over the next two months.

Combined, the three units will add 2,000 megawatts of generating capacity to the Ontario system, or enough to fill about 10 per cent of the province’s demand on a mild spring or fall day.

But the IMO notes that bringing back laid-up nuclear units is tricky; the Pickering A unit is almost three years behind schedule, while the first Bruce A unit had originally been due back in service May 1.

Even with all three units returning, the IMO says supplies will be very tight this fall. Power system planners build in a supply cushion, which they call a reserve margin, to cope with surges in demand.

The reserve margin will be lower than required from early October through to the end of December, the IMO figures show. That means the province will have to rely on imports to keep the lights on and maintain a safety margin.

If the re-tooled nuclear plants are delayed in returning to service, shortages will also occur next summer, the forecast shows. The forecast notes that extreme weather – very hot summer temperatures or a cold, stormy winter – puts even more strain on the electricity system.

The forecast shouldn’t provide much comfort, said Tom Adams, executive director of Energy Probe. "The outlook is still dicey," he said in an interview.

While extreme weather generally occurs in short bursts, extremes are almost guaranteed to occur at some point over an 18-month period, he said.

The province rented "temporary" gas and diesel generators to help out in periods of high demand starting this summer. The province had planned to install about 400 megawatts, but the tender call produced only 250.

Adams had predicted the temporary generators would become long-term fixtures.

"I don’t see anything here that would encourage me to change my views," he said.