Generators shut, blackout fears raised amid strike by Hydro One workers

"It's not inconceivable they could be blacking out customers," warned Tom Adams of the watchdog group Energy Probe.

Dozens of pickets from the Society of Energy Professionals prevented enough essential staff from getting to their jobs that Nanticoke, owned by Ontario Power Generation, had to shut six of its eight coal-fired units by late afternoon.

That prompted officials to put out an alert asking people to reduce their power consumption June 26.

OPG was seeking an injunction last night to stop the kind of picketing that forced the shutdown, but a union spokesperson said picket lines were taken down as of 8 p.m.

The six units at the plant on Lake Erie provide a total of 3,000 megawatts of power — about 10 per cent of the province's electricity generating capacity recently.

The Independent Electricity System Operator, which manages the province's hydro needs, said the maximum amount of electricity that can be imported is about 4,000 megawatts; by late yesterday afternoon, the hourly imports were running at more than 2,300 megawatts, Canadian Press reports.

Energy Minister Dwight Duncan last night said the loss of six of the eight units "challenged the reliability of the system. It really stretched things."

Energy experts said the province's electricity supplies should be adequate this weekend, with few factories and offices operating, but that could all change.

The union is striking over demands from Hydro One, which runs the province's electricity transmission lines, for a two-tier wage scale.