Could the heat wave cause power outages? How Canadians can prepare

As an intense heat wave in central Canada ushers in the official start of summer this week, experts are warning about increasing pressures on the country’s electricity systems that have the potential to cause power outages.

Heat warnings were in effect in several regions of southern Ontario and Quebec on Monday, with “dangerously hot and humid” conditions forecast through most of the week, according to Environment Canada.

Heat waves can put strain on the electricity systems in a “two-angled attack,” said Ryan Ness, an adaptation research director at the Canadian Climate Institute in Toronto.

To beat the heat, more people will be running their air conditioning higher, increasing the demand on the system, he said.

And as more electricity is demanded for things like air conditioning, the extra heat generated through the infrastructure adds even more to the “temperature stress” on transformers and other parts of the electricity system, Ness explained.

That could result in power failures or outages.

“Electricity system infrastructure like transformers can only handle so much heat,” Ness said.

1:40 Millions of Canadians face intense heat wave

Some cities are expecting daytime highs to hit 30 to 35 C and humidex values of 40 to 45 through much of the week, according to Environment Canada.

Ontario’s Independent Electricity System Operator (IESO) said the province’s electricity system has the tools it needs to remain reliable this week and throughout the summer.

“The IESO is prepared for increased demand from high temperatures, closely monitoring system conditions on a second-by-second basis to ensure a stable and reliable supply throughout the province,” Andrew Dow, a spokesperson for the operator, said.

“The heat can impact electricity infrastructure, and so we also closely monitor transmission and generation equipment to manage any potential impacts,” he told Global News in an emailed statement.

Hydro-Québec, which provides power to 4.4 million people in the province, said heat waves don’t have a big impact on its equipment or grid and it has contingency plans for different weather conditions.

“We sometimes choose to report service interruptions planned for maintenance in order to make sure that our clients have access to air conditioning,” Cendrix Bouchard, a Hydro-Québec spokesperson, told Global News in an emailed statement.

“Air conditioning amounts for five per cent of a household electricity consumption in Quebec, therefore the impact of heat waves is marginal,” Bouchard said.

Ness said the current heat wave does not pose a concern to Canada’s grid systems, which are typically resilient to these kinds of temperatures, but there’s always the potential for heat waves that approach and exceed 40 C to knock power out.

He pointed to the 2021 heat wave in British Columbia that saw several local outages, where substations or transformers blew because of the heat, because the system wasn’t designed to handle it, Ness said.

Power outages during a heat wave can put lives at risk, which is why preparation is key, experts say.

Studies show that if a power outage of two to three days coincides with a heat wave, deaths from the heat could increase from hundreds into the thousands “very easily,” said Caroline Metz, managing director of climate resilience and health at the Intact Center on Climate Adaptation at the University of Waterloo.

“We do have to be prepared in the event of a power outage or for a time when our electricity grids are less reliable and that means putting in place backup power,” she told Global News in an interview.

It’s also very important for homeowners or tenants to be able to have access to cooling either in their own homes, a cool room in a multi-unit building or to be able to access a community cooling centre, Metz said.

During hot summer days, roughly one-third of electricity use in Ontario comes from air conditioning, according to IESO.

“Homes and businesses participating in IESO programs reduce their energy consumption during peak times and help ease the pressure off the system,” Dow said.

4:20 Vancouver to plant more trees to combat heat

To prepare for a power outage, the Canadian Red Cross advises to make a personalized emergency kit, including drinking water, food, cash and medical prescriptions, for at least three days.

Flashlights with working batteries should be accessible and seek professional advice if you are considering getting a generator, the Red Cross says.

As heat waves become more intense, Ness stressed the need to ensure that the power transmission and distribution systems are upgraded and equipped to handle the new loads.

“What we need to do is make sure that we are keeping our electricity system resilient as the temperature gets worse and as more and more people install air conditioning, especially in parts of the country that have never needed it before,” Ness said.

“It’s really a life-and-death situation and we need to make sure that those who need air conditioning have access to it, when it’s hottest and that means making sure our electricity system is running, at the peak of heat waves.”

— with files from Global News’ Gabby Rodrigues and Uday Rana