Rolling power outages that hit Alberta on Tuesday afternoon have ended for the day, officials have announced.

As of 5:59 p.m. MT, power had been restored to Red Deer and Edmonton with no more outages expected for the evening. Lethbridge is preparing to restore power shortly, but is cautioning that demand remains high.

The blackouts followed a Level 3 energy emergency alert issued by the Alberta Electrical System Operator (AESO) earlier Tuesday.

The Alberta electrical grid came under intense strain during record-setting heat, and AESO had warned that one-hour blackouts would hit communities across the province. Five coal-fired power plants are out of service today along with several other plants.

Flood-affected areas and critical infrastructure such as hospitals would be exempt from blackouts, AESO said.


Alberta experienced rolling blackouts as the power grid came under strain due to intense heat. (CBC)

AESO said it could see the effect of the blackouts in reducing the province's energy demands.

Alberta set a power use record earlier today with 10,062 megawatts being consumed as of 4 p.m. That figure is now down to 9,685 megawatts, which is below the 2012 record.

Heat strains power grid

The blackouts came on the heels of intense heat across southern Alberta. Twenty heat records were broken yesterday in the province and more will likely follow, said CBC Calgary weather specialist Warren Dean.

"Calgary's record of of 33.3 C for July 2 is looking to be broken," said Dean.

"We've been pulling in very warm and dry air from the deserts in the United States for about a week, and with that, our temperatures have kept rising."

As of 3:30 p.m. MT, Calgary was sitting at 32 C, with the humidex making it feel like 39. On this day in 2012, Calgary was at 23 C, according to data from Environment Canada.

Police are cautioning people not to leave animals inside cars. Over the past few days, police in Lethbridge have responded to a number of reports of animals left unattended inside hot vehicles.

According to the Society for the Prevention of Cruelty to Animals (SPCA), temperatures in a parked car, even in the shade with a window partially open, can rise enough to seriously harm an animal in as little as 10 minutes.

Animals left in hot cars are at risk of heat stroke and death. Anyone who sees an animal in distress inside a vehicle is asked to contact police.

Weather system moves from B.C.

The intense heat came as a system that caused record-breaking temperatures in B.C. yesterday moved into Alberta.

B.C. saw 15 heat records shattered by the system on Canada Day and much of Alberta is expected to be eight to 12 degrees above seasonal average throughout Tuesday afternoon.

Energy reserves across Alberta are tight due to recent flooding and increased demand, said AESO.

Five coal-powered power plants are currently off-line and Alberta is importing more than 600 megawatts from B.C. and Saskatchewan. Wind generation is also very low.

There are several ways people can help reduce demand on the electrical system. AESO recommends that people:

  • Turn off unnecessary lights and unplug electrical appliances.
  • Minimize the use of air conditioning.
  • Close blinds, shades or drapes during the hottest part of the day.
  • Run major power-consuming equipment such as dishwashers, washers and dryers during off-peak hours (after 7 p.m.)

Thunderstorm watch

Calgary is also under a severe thunderstorm watch for Tuesday afternoon and evening. High humidity is the fuel for thunderstorms and the southern Alberta region is very humid.

Environment Canada said the storm could have large hail and damaging winds.

People are advised to monitor weather conditions and listen for updated statements. If threatening weather approaches, people should take immediate safety precautions.

There is also a potential for hail and a possible tornado in northern and central Alberta as a cold front slides out of the foothills west of Edmonton.