Kieron Lang
CTV News
August 16, 2003

A nine-second event that triggered a cascading power outage Thursday demonstrated the vulnerability of the Eastern Interconnect electrical grid. It’s an integrated system that supplies power to Ontario and the northeastern United States.

The grid is the catch-all phrase for the transmission towers, power lines and computers that link generators to distribution centres and, eventually, to your desk lamp.

Since electricity can’t be stored, it’s generated as needed. When one area has a shortage, it can make up the balance with supplies from others with surplus energy. Power is shifted through a system of substations, regional distribution centres and trunks that shunt the power to customers.

"There is safety in numbers or interconnectedness – most of the time," Energy Probe’s Norm Rubin told The Canadian Press. "The grid has saved Ontario from blackouts."

But when some element in the system fails, that interconnectedness can amount to its downfall.

At about 4:10 p.m. EST Thursday, the Eastern Interconnect was humming along as usual.

Click here to see a full map of the North American power grid

Then something, somewhere – the root cause of the outages remains unconfirmed, but is now believed to have been a blown transmission line near Cleveland, Ohio – went wrong.

As a result, the system surged – causing machines along the line to react automatically.

Circuit breakers tripped and fuses blew, taking equipment off the grid to protect it from the suddenly unstable flow of electricity.

As segments of the grid dropped off, the level of demand fell, forcing producers with nowhere to store their electricity to also shut down.

It took about nine seconds – more than 100 power plants, including 21 nuclear reactors operating in the U.S. and Canada, automatically went offline.

The consequences were felt by up to 50 million people in Ontario and seven U.S. states, who were suddenly without power.

Then, with the system shut down, the problem became one of turning the lights back on. Unlike flicking on a light at home, the system has to be synchronized before generators can be brought back online.

Even if it was as simple as throwing a switch, the effect wouldn’t be instant. Coal and gas-fired stations, for example, take time to build up enough steam to power generators once they’ve cooled down.

And nuclear plants – which provide 40 per cent of Ontario’s electricity – can take up to 48 hours to restart after a shutdown, as they go through the process of heating up and reconnecting to the electricity grid.

So, efforts to restore full power – further complicated by difficult task of balancing load, or supply and demand – meant continuing rolling blackouts to prevent larger outages.

Provinces distance themselves from Ontario

In the wake of the blackouts, power companies and politicians from other parts of Canada were quick to point out the differences that kept their systems running while Ontario’s failed.

Alberta and British Columbia are part of the Western Interconnect, which allows Canadian power to flow down into Washington State and along the coast to California – along one cross-border transmission line.

Because power is moving down a single line, it’s relatively easy to cut the Canadian system off from the U.S. when needed. In that way, the two westernmost provinces can operate as islands unto themselves – a situation that already occurred twice in 1996 when blackouts affected many western states, but largely bypassed B.C.

In Ontario, the network is far more intertwined with that of the U.S.

Another advantage that B.C. shares with Quebec is the fact most power comes from hydro-electric generation. Built around running water, rather than heat, those systems can be returned to operation in an hour.

Also, because much of Quebec’s power is generated in the province’s north, it is not synchronized with major transmission lines in the rest of North America.

In New Brunswick, power was preserved by the breakers designed to trip when faced with a power surge. A 700 megawatt surge bore down on the province from Maine on Thursday. Within 25 seconds, New Brunswick’s generators had been sealed off.

Eves faces accusations

Ontario Premier Ernie Eves could not explain why his province did not have better safeguards in place. Major changes had been proposed after a similar blackout more than 30 years ago, involving Ontario and northeastern U.S. states.

"Following (the blackout of) 1965, it’s my understanding that those in charge did take such steps (to protect Ontario’s grid)," Eves said.

But Tom Adams of the group Energy Probe told CTV News he’s not convinced.

"Ontario has many vulnerabilities in its power systems. We’ve got a power system that’s got a host of problems," Adams said, echoing a comment U.S. President George Bush made the day before.

"We’ve got an antiquated system," Bush said, adding that the outage is a signal the American power grid needs to be modernized.

Ontario’s Conservative government has been criticized for years for being more interested in privatizing electricity than in ensuring the province would have enough energy.

"The blackout demonstrates the public power system Ontarians have built together over the last 100 years is more essential today than ever," NDP Leader Howard Hampton said Friday.

The Tory government opened the market to competition in May 2002, but Eves backtracked six months later. Soaring consumer bills prompted him to freeze retail rates at 4.3 cents a kilowatt an hour.

Critics have said that the artificially low price removed any incentive for people to conserve electricity usage.

At the peak of the power shutdown Thursday nearly 62,000 megawatts of electricity flowing to customers was lost, making the event the largest in North American history.