SACRAMENTO, Calif. — Staring at the possibility of Labor Day blackouts, managers of California’s power grid issued an extended Flex Alert for Monday afternoon and evening but warned that voluntary conservation might not be enough to keep the lights on.
The Independent System Operator, which runs the grid, also issued a Stage 1 energy emergency alert Monday morning, a signal that supplies will be very tight. The grid “is forecasting an energy deficiency, with all available resources in use or forecasted to be in use,” the ISO said.
A Stage 1 alert is a call to generators and transmitters to make as much power available as possible. Blackouts would be imposed if the grid reaches a Stage 3 emergency.
The Flex Alert was in effect from 4 to 10 p.m., an hour longer than usual, underscoring the increasingly dicey conditions on the grid as temperatures across parts of inland California were expected to soar to 110 degrees or higher.
It marked the sixth straight evening of Flex Alerts as the Independent System Operator, which runs the grid, urged Californians to conserve as much energy as possible. Even so, the grid’s chief executive Elliot Mainzer said the grid could experience significant shortfalls Monday and in the days ahead as the state struggles to avoid a repeat of the August 2020 rolling blackouts.
“We are looking at deficits for ... Monday in the 2,000 to 4,000 megawatt range between the hours of 5 p.m. and 10 p.m.,” he told reporters Sunday afternoon.
That could take as many as 3 million households offline.
“Obviously the chances of ... of interruption of electrical service are higher than they have been so far.”
Mainzer said it’s almost a certainty that stronger measures will be needed in the coming days to avoid rolling blackouts of the sort California experienced in 2020. Those include power curtailments for commercial and industrial customers who have so-called interruptible rates, in which they receive cheaper power but agree to have their energy use curbed during crunch times.
Mark Rothleder, the ISO’s chief operating officer, said Californians have done an admirable job so far of responding to the Flex Alerts; the number of megawatts saved has actually increased as the heat wave has continued. Another saving grace has been comparatively mild weather in the Pacific Northwest, enabling that region to export more electricity to California.
But the grid has experienced considerable setbacks. Rothleder said three gas-fired power plants conked out and were still struggling to regain full power, erasing about 1,000 megawatts in total. The drought has severely curtailed hydroelectric supplies all summer.
“We are going to need people to step up and sustain those efforts,” Mainzer said.
Energy demand was expected to peak sometime Monday evening at 48,817 megawatts.
The biggest crunch on the power grid is expected Tuesday, when temperatures in the Sacramento Valley could reach 115 degrees. Mainzer said electricity demand could top out at 50,099 megawatts. “Our goal is to make sure we do not reach that number,” Mainzer said.
Tuesday’s peak would be just shy of the record 50,270 megawatts consumed July 24, 2006. The state avoided blackouts that day, but California’s power portfolio has changed considerably in the past 15 years, creating new areas of vulnerability.
In particular, California’s increasing reliance on solar power and other renewable sources has made the grid susceptible to blackouts in the early evening, when solar panels go dark but the weather stays hot. The state had two straight nights of rolling blackouts in August 2020 and nearly had a repeat during the July 2021 heat wave.
During a Flex Alert, Californians are urged to cool off their homes ahead of time and then turn up thermostats to 78 degrees. They also are asked to defer using heavy appliances.
“We know this has been a long haul,” Mainzer said, “and it’s going to get more difficult.”
Temperatures are expected to stay well above 100 degrees in the capital region for the bulk of the week after the National Weather Service extended its excessive heat warning through Thursday night.
In addition, air quality managers issued the year’s fourth Spare the Air alert for Monday, as the heat is expected to keep ozone levels unhealthy for sensitive groups. Before the heat wave, the region had just one alert day in 2022.
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