Under the strain of triple-digit temperatures in a punishing heat wave, California electric grid operators warned Tuesday of possible rolling blackouts but never took the step.
The California Independent System Operator, which oversees the state’s power grid, at 5:17 p.m. declared an Energy Emergency Alert 3, which is the level at which rolling blackouts could be ordered.
Californians got an emergency alert on their phones with an audible alarm and an urgent plea to save power.
At 8 p.m., the system operator, or ISO, tweeted that it had ended the emergency alert. A spokesperson for the operator said no rotating outages were ordered.
“Consumer conservation played a big part in protecting electric grid reliability. Thank you, California!” the ISO tweeted.
Tuesday had been predicted as a day of peak demand during a heat wave that has baked parts of California since last week.
And it was: The system operator said Tuesday night the state set a record for peak energy demand, 52,061 megawatts, surpassing the previous record, 50,270 megawatts on July 24, 2006.
Tuesday was the first time an Energy Emergency Alert 3 was issued since a heat wave began affecting large parts of the state last week — although calls for conservation known as “flex alerts” had been issued every day since Aug. 31.
The high energy use Tuesday came on a day almost the entire state was under an excessive heat warning.
Before the emergency alert was issued, Pacific Gas & Electric warned earlier Tuesday that 525,000 customers could experience power outages if they were ordered.
The last time the ISO ordered rolling blackouts was in August 2020. Before that, the last time rolling blackouts were ordered in California was in 2001.
There were other power outages in the state Tuesday, including some related to the heat.
Around 50,000 Pacific Gas & Electric customers in the San Francisco Bay Area were without power as of 9:30 p.m. Tuesday, utility spokesman J.D. Guidi said, but those were not rolling blackouts and were mostly heat-related.
The most common heat-related outage is transformer failure, he said. Transformers usually cool down at night, but during heat events temperatures can stay high and they can fail.
Downtown Sacramento hit 116 degrees Tuesday, Bakersfield reached 113 degrees, and it was 93 degrees in downtown Los Angeles, according to the National Weather Service.
Temperatures of 107 degrees were recorded near Hemet in Riverside County, where firefighters were battling the Fairview Fire, which broke out Monday and killed two people.
Farther north, San Jose reached 109 degrees, Napa was at 114 degrees, and Santa Rosa hit 115 degrees, the weather service said.
More than 44 million people were under excessive heat warnings Tuesday across California and parts of Nevada and Arizona, according to the weather service. Another 13 million were under heat advisories that also covered parts of Idaho and Utah.