With scorching temperatures expected to peak Tuesday from an ongoing heat wave, California is poised to hit a new record for electricity demand as air conditioners huff and chug in homes and offices across the sweltering valleys.
And with that record demand comes a question Californians are becoming all too familiar with: Will there be enough power, or will the lights go out to protect the electric grid from systematic collapse?
By Tuesday afternoon, California’s grid operator was warning that electricity supplies would be so short by 5:30 that the state would reach its highest stage power emergency when rotating outages — rolling blackouts — are imminent. Pacific Gas & Electric began posting outage blocks likely to be affected online.
“Today the demand for power on the California grid is expected to be at an all time high and we’ve entered what is going to be the most challenging day so far of this unprecedented heat wave,” said Elliot Mainzer, president and chief executive of the California Independent System Operator, which runs the power grid.
Mainzer said power conservation and some last minute emergency power supplies helped avert outages Monday, but that “tonight, we’re going to have to dig even deeper” to avoid “the real potential for rotating outages.”
If electricity supplies can’t meet demand, utilities including Pacific Gas & Electric, would have to rotate outages to blocks of customers for an hour or so to lighten the load. The state last saw such rolling blackouts over two days in August 2020, affecting about 800,000 homes and businesses and lasting anywhere from 15 minutes to about two and a half hours.
Before that, the last rolling blackouts were during the state’s electricity crisis of 2000 and 2001 caused in part by a botched deregulation scheme, which factored into the 2003 recall of Gov. Gray Davis.
The California ISO said peak electricity demand Tuesday is expected to exceed 52,000 megawatts, which would set a new record from the previous high of 50,270 megawatts in 2006. A megawatt — 1,000 kilowatts — is roughly enough electricity for the demand of 750 homes at once.
The ISO was projecting supply deficiencies of 400 to 3,400 MW between the hours of 5 p.m. and 9 p.m. Tuesday, and pleading with residents and businesses to continue to reduce power use in the late afternoon.
“Record-breaking temperatures are leading to historic high forecasted demands for power,” the ISO said, putting even greater strain on the grid and “significantly increasing the likelihood of rotating outages unless consumers can reduce their energy use even more than they have so far.”
The ISO issued its seventh straight “Flex Alert,” calling for electricity consumers to cool their homes and businesses as much as possible earlier in the day and then reduce their power use from 4-9 p.m. Requested conservation steps include setting air conditioning thermostats to 78 degrees or higher, avoiding major appliances such as washers and dryers and charging electric vehicles and turning off lights when not in use.
Those conservation efforts, the ISO said, have paid off so far, lowering demand by about 2,000 megawatts Monday afternoon. Emergency assistance added an additional 800 megawatts of power to the system. The result, demand Monday peaked at 49,020 megawatts. That’s still higher than the 47,121 peak demand in August 2020 the last time rotating outages were needed.
But Tuesday, grid operators were gradually upping their estimate of where demand would peak.
“This heat wave is set to be the hottest and longest on record in California for September,” Gov. Gavin Newsom said in an announcement Tuesday. “We are now heading into the worst part of it — the risk of outages is real. Your efforts have paid off so far, but we need everyone to double down to save energy after 4 p.m.”
By early afternoon, the grid operator issued a second straight Energy Emergency Alert 2 for 4-9 p.m., which requests emergency energy from all resources and provides financial incentives for reducing energy use. An Energy Emergency Alert 3 was expected for 5:30 p.m., indicating insufficient reserves and that rotating outages are imminent. The ISO said that If outages are initiated, consumers can expect to receive notifications from power providers on which areas will be affected and for how long.
Severin Borenstein, professor of business administration and public policy and faculty director of the Energy Institute at the University of California-Berkeley’s Haas School of Business, noted that rolling blackouts aren’t the same as the Public Safety Power Shutoffs to avoid power lines sparking wildfires during high winds. Those outages can last for days as utility crews must inspect lines across wide areas for damage before re-energizing them.
Though the state avoided rotating outages on the Labor Day holiday, it wasn’t far from requiring them.
“It was close,” Borenstein said. “It definitely was not assured.”
Even without rotating outages, heat can damage electrical equipment and cause localized outages. PG&E on Tuesday reported about 15,000 Bay Area customers lost power during the day due to heat-related electrical equipment failure, including 8,000 in Santa Clara County and 4,000 in Concord and Pleasant Hill, spokeswoman Deanna Contreras said.
But the threat of outages can increase as the heat wave wears on, Borenstein said, as buildings don’t have enough time to cool off overnight before temperatures rise again the next day.
What makes ensuring power supply tricky for utilities and grid operators is that it’s unclear how much the principal source of power demand during heat waves — air conditioning — is increasing. Many homes and businesses near the coast that traditionally didn’t have air conditioning have been installing cooling systems, but it’s not being tracked.
“You find out on the hottest day of the year just how bad it’s going to be,” Borenstein said. “The forecasters do their best, based on previous relatively hot days, but we don’t know until we get to the day.”
Check back for more on this developing story.
Contributed by local news sources