California blackouts avoided but heat wave strains power grid
California Heat Wave
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Staving off rolling blackouts Labor Day evening, managers of California’s beleaguered power grid declared — but later canceled — an energy emergency alert Monday.
But blackouts still loomed as a possibility Tuesday, when workers were returning to their offices and electricity demands were forecast at an all-time high.
The Independent System Operator, which runs the electricity grid, declared a Stage 2 emergency alert effective 6:30 p.m. Monday, a sign that supplies were turning increasingly tight as temperatures rose to 110 degrees and beyond.
The alert ended at 9 p.m.
Blackouts — the first in two years — would likely have come if the ISO had to declare a Stage 3 alert.
Complicating matters, the ISO also declared a “transmission emergency” for Northern California earlier Monday evening, saying it needed to “relieve overloads in the Palermo area” of Butte County.
“We have now entered the most intense phase of this heat wave,” Elliot Mainzer, president and chief executive of the ISO, said earlier in the day. “The potential for rotating outages has increased significantly.”
Mainzer said the grid was looking at “energy deficits of 2,000 to 4,000 megawatts, which is as much as 10% of normal electricity demand.” That could take as many as 3 million households offline.
The Flex Alert — a call for voluntary conservation for a sixth straight evening — 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.
Mainzer said Californians have rallied during the heat wave, reducing their consumption by nearly 1,000 megawatts both Saturday and Sunday nights — enough electricity for more than 750,000 households.
But to get through Labor Day unscathed, he said those conservation efforts would have to double or triple.
At around noon, power consumption was expected to peak Monday evening at 48,961 megawatts. But at 6 p.m. it had already topped that prediction by a few megawatts.
Tuesday was shaping up as considerably worse: a peak demand of 51,144 megawatts, breaking a 16-year-old record for energy use in California.
“We are on razor thin margins,” said Siva Gunda, vice chairman of the California Energy Commission.
The state scrambled to keep the lights on. A small fleet of new gas-fired power generators in Roseville and Yuba City, authorized by the state last year and operated by the Department of Water Resources, was turned on for the first time. They generated enough power for about 120,000 homes.
Additionally, Gov. Gavin Newsom’s emergency order last week enables industrial businesses and others to fire up backup generators that otherwise would be prohibited by air-pollution regulations, Gunda said. “A lot of our participants can turn on their (generators) and take load off the grid,” he said.
Some customers with so-called interruptible rates — which provides discounts but leaves them vulnerable to curbs in energy availability as supplies dwindle — could be taken offline.
Meanwhile, Newsom’s staff was calling big commercial and industrial firms, asking them to curtail their usage so blackouts could be avoided, said Newsom’s spokeswoman Erin Mellon.
“Inelegantly called ‘dialing for megawatts,’” she said.
Help could also come from utilities such as SMUD, the Sacramento Municipal Utility District, which isn’t part of the ISO’s grid network and wouldn’t necessarily have blackouts if they occur. Mainzer said various utilities outside the ISO system typically share power with each other during crunch times.
“There’s an expectation among the utilities,” Mainzer said. “They’ve been working together for years.”
SMUD had its hands full with near-record power demands Monday. Whether it will be able to share power with the ISO’s statewide system “will have to be a gametime decision,” said SMUD spokeswoman Lindsay VanLaningham. “If we have extra, we will.”
Like the state, SMUD was asking Sacramento residents to turn up their thermostats to 78 degrees Monday evening to save power. VanLaningham said it appeared Monday evening that SMUD would avoid rolling outages of its own.
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. All told, 7,735 megawatts of power were out of commission as of Monday morning, according to ISO data.
The biggest crunch on the power grid is expected Tuesday, when temperatures in the Sacramento Valley could reach 115 degrees and power demand could set the system’s record. “Our goal is to make sure we do not reach that number,” Mainzer said.
The current 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.
Since then the state has been able to bring on more than 8,000 fresh megawatts of capacity, including more than 2,000 megawatts of battery storage — a system for marshaling excess power generated by rooftop solar panels and other sources — Gunda said.
“Imagine where we’d be if we hadn’t done the stuff we’ve done the last two years,” said Mellon, Newsom’s spokeswoman.
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 about to get even 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.
This story was originally published September 5, 2022 10:14 AM.