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California's Extreme Heat Wave Prompts Rolling Power Outages

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California's heat wave has strained the state's electrical system. Pacific Gas & Electric announced on Friday that it would turn off power in rotating outages for about an hour at a time until 11 p.m. The state's heat wave also brings the threat of wildfires and spreading coronavirus infections as people flock to beaches and recreation areas.  (Marcio Jose Sanchez/AP Photo)

Updated 9:30 a.m. on August 15

For the first time in nearly two decades, state power managers ordered rolling power outages across California. Hundreds of thousands lost power Friday night as a heat wave strained the state's electrical system.

The California Independent System Operator, which manages the power grid, declared a Stage 3 emergency around 6:30 p.m. and directed utilities around the state to shed their power loads. A Stage 3 Emergency indicates the demand for power outstrips the available supply.

Shortly before 9 p.m., the grid operator lifted the emergency declaration.

“Extreme heat is really the driver behind this,” said Anne Gonzales, spokeswoman for the power grid operator.


PG&E, the state’s largest utility, tweeted that it would turn off power to about 200,000 to 250,000 customers in rotating outages for about an hour at a time until around 11 p.m.

The decision to implement rolling outages came as temperatures around the state hit triple digits in many areas, and air-conditioning use soared.

The heat wave is expected to last through next week and the power grid operator will decide whether to continue the rolling outages on a day-to-day basis, Gonzales said.

“We’re dealing with weather, clouds, wildfires ... these are quickly evolving situations, quickly changing,” Gonzales said.

Stanford University energy researcher Michael Wara said energy regulators were faced with a choice: “Cross their fingers and hope for the best” or preemptively turn off power for customers. “If you don't make it over that peak, if you're not lucky when you cross your fingers, you can get a system-wide blackout that would have extended beyond California's borders and might have lasted for several days,” he said.

PG&E spokesperson Jeff Smith said "we would just encourage all of our customers to conserve as much energy as possible over the course of the next few days as we're going to see continued multiple days of extreme heat."

California ISO's Gonzales said temperatures were 10 to 20 degrees above normal in some areas, and that cloudy weather from the remnants of a recent tropical weather system reduced power generation from solar plants.

The state urged the utility to buy more power, but a high-pressure system building over Western states meant there was less available.

Temperatures and energy use dropped during the evening, and California ISO said the outages ended by 9 p.m.

The last time the state ordered rolling outages was during an energy crisis in 2001. Blackouts occurred several times from January to May, including one that affected more than 1.5 million customers in March. The cause was a combination of energy shortages and market manipulation by energy wholesalers, including Enron Corp., which infamously drove up prices by withholding energy supplies.

Counties up and down the state reported scattered outages, although the city of Los Angeles, which has its own power generating system, wasn’t affected.

Police departments warned people to watch out on roads where stoplights were out.

In Sonoma County, the Santa Rosa Police Department received a flood of calls and pleaded with residents: “Please do not call 911 unless you have an emergency.”

Heat wave continues

The heat surpassed historical records in several cities Friday. Downtown San Francisco hit 90 degrees, topping a high of 86  that was set on Aug. 14, 1995. Salinas hit 102, 18 degrees above the record set just last year. Palm Springs hit 120, breaking a 2015 record by several degrees.

Sweltering weather is expected to continue into Wednesday across greater Los Angeles, the Central Valley, Sierra Nevada foothills and parts of the San Francisco Bay Area.

Santa Clara, Alameda and Contra Costa counties opened cooling centers that will welcome people this weekend from the afternoon to the early evening.

There are 12 cooling centers across Santa Clara County, including three in San Jose alone. Due to the coronavirus pandemic, cooling centers will require people to have their temperatures taken and answer some health screening questions before they enter.

Charlotte Graham from San Jose's Parks and Recreation Department says she's never seen the centers reach capacity but that could change this year: "With places like malls and movie theaters being closed where people might go to get air-conditioning, those are not available right now, so we very well could see an uptick in visitation."

San Jose's cooling centers will remain open until at least next Wednesday, Aug. 19.

Officials in San Francisco, on the other hand, are concerned about coronavirus transmissions during the heat wave. As a result, the city won't be operating cooling centers, according to Mary Ellen Carroll, executive director of the city's Department of Emergency Management.

San Francisco officials said the city is recommending people stay home and that if the heat indoors gets intolerable to go outside to a shady place where they can stay cool and distant from other people.

California Heat Wave

“Congregate indoor sites are not safe necessarily during COVID-19. It is better to follow other instructions during this heat wave,” Carroll said.

Carroll encouraged residents to check on family, friends and neighbors, especially older adults and those in frail health, and reminded people to always wear a face mask when in the vicinity of people who don’t share their household.

“We know it’s going to be beautiful out this weekend but we just want everyone to remember that we are in a very serious response to this COVID-19 virus,” Carroll said.

In addition to the possibility of heatstroke and other hot-weather illnesses, health officers were concerned that people will pack beaches, lakes and other recreation areas without following mask and social distancing orders — a major concern in the state that has seen more than 600,000 coronavirus cases.

Israel saw a COVID-19 resurgence after a May heat wave inspired school officials to let children remove their masks, Dr. George Rutherford, an epidemiologist at UCSF, told the San Francisco Chronicle.

“People will want to take off their masks when it’s hot,” Rutherford said. “Don’t do it.”

KQED's Lily Jamali, Adhiti Bandlamudi, Raquel Maria Dillon and Julie Chang contributed to this report.


This report contains additional reporting from the Associated Press.

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