The Alberta Electric System Operator says 10,441 megawatts of power was used between 1 p.m. and 2 p.m. local time Thursday.
The operator says it's confident the system can handle the high demand.
It says more than 1,700 MW of supply has been added to the system since the start of 2014, including nearly 350 MW of wind and more than 1,000 MW of gas-fired generation.
There has been a 0.3 per cent growth in demand for power year-over-year in Alberta.
Summer peak demand was previously set at 10,419 MW on July 30, 2014.
As of Thursday afternoon the thermometer had reached 32 C in Edmonton and 30 C in Calgary, and the forecast for the next few days is more of the same. No rain is forecast until next week.
“Reliability is always a priority for us to ensure Albertans have the electricity they need to run their homes and businesses," Miranda Keating Erickson, vice-president of operations with the AESO, said in a news release.
"Because of the substantial new generation that has come online over the last year, we are confident we have enough supply to get us through the season of typically higher demand."
Due to 30 C and higher temperatures, Alberta Health Services has issued a heat advisory for the whole Calgary zone.
Effective immediately, residents of and visitors are advised to take precautions to protect themselves, their families and their neighbours from the potentially harmful effects of the sun, including burns, heat-related exhaustion and heat stroke.
"Normal activity that may be safe on a cool day might be dangerous in current weather conditions.," said Dr. Brent Friesen, medical officer of health for the zone.
"If you start to feel overheated, stop your activity immediately, seek shade and drink fluids."
Friesen says people should be watchful for vulnerable individuals, including children, seniors, individuals with pre-existing respiratory or cardiovascular conditions, outdoor workers, as well as those who are socially isolated.
The heat advisory is in effect until Sunday.
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