California dodges another rolling blackout
Conservation measures and sufficient supplies avert outages amid broiling heat wave
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For yet another night, California on Sunday narrowly avoided a repeat of last month’s rolling blackouts.
Just as it had on Saturday, the California Independent System Operator, which manages about 80 percent of the power grid in the state, declared a Stage 2 Emergency — just one level shy of implementing statewide power outages.
CAISO official earlier in the day feared a shortfall between supply and demand on its system of about 4,400 megawatts. Anxiety heightened after a transmission line carrying power from Oregon to California and an in-state power plant went offline unexpectedly.
But sufficient amounts of energy resources and conservation efforts by household utility consumers helped keep supplies slightly ahead of a surge in electricity demand as the state sweltered through a second day of a broiling Labor Day weekend heat wave.
At 8:36 p.m., the system operator, also known as the CAISO, declared via Twitter the danger had passed.
“No power outages on the high-voltage #electricity system tonight,” the grid operator said. “Thank you, California, for protecting the grid again.”
According to the grid operator’s website, demand peaked at 47,235 megawatts — within striking distance of the all-time record of 50,270 megawatts set on July 24, 2006. But Sunday’s peak came in about 1,400 megawatts shy of what CAISO officials had anticipated earlier in the day.
Grid officials at a 1 p.m. conference call with reporters warned the outages could affect as many as 2.5 million to 3 million customers, with a total duration lasting between three to four hours.
The CAISO requested and received help Sunday from the U.S. Department of Energy, which issued an emergency order allowing California’s grid operator to run three generating units in the greater Los Angeles area to “operate at their maximum generation output levels” during the heat wave to preserve the power system’s reliability.
Things looked shaky when at 5:55 p.m. the CAISO ordered the Stage 2 Emergency order, which allows the grid manager to use reserve power and to tap into emergency assistance from neighboring grid authorities.
“We need everyone’s help now!” the CAISO Twitter feed said at 7:08 p.m. “Please conserve to avert or limit outages.”
Under Stage 3, the highest level, the grid operator orders utilities such as San Diego Gas & Electric to start shedding load — that is, cutting off power to certain areas so that supplies can match demand.
The power companies then determine which segments of their service territories lose power.
A major challenge grid managers have faced comes when the state’s abundant amount of solar production quickly ramps down as the sun sets. The CAISO then has to find supplies of other sources of energy to make up the difference.
“The cooler temps (as the sun sets) means less demand on the electricity system,” the CAISO tweeted at 7:25 p.m. “But it also means solar production is winding down, removing thousands of megawatts of resources.”
The heat wave has also strained the electric grids in neighboring states, which often supply California with energy imports when they are needed.
“Everybody is seeing tight supplies,” said John Phipps, the CAISO’s director of real time operations.
While the weather is expected to stay hot across the state through Monday, high temperatures are anticipated to be not nearly as severe as seen Saturday or Sunday, which figures to give grid operators a break.
Power problems in San Diego County
The threat of blackouts came as SDG&E reported impacts on its system due to the Valley fire that so far has scorched 9,850 acres and destroyed 11 structures in the Carveacre and Lawson Valley areas in rural East County.
The blaze caused the Sunrise Powerlink to trip. The 117-mile transmission line connects renewable energy resources from Imperial Valley to San Diego. SDG&E officials said no customers lost power due to the line being out of service, however.
Once Cal Fire tells SDG&E the area is safe, crews will go in and determine what is required to put the Powerlink back into service.
In addition, as of 5 p.m. Sunday, five circuits on SDG&E’s system were down because of fire damage.
Among the five, a line serving 1,462 customers in the Casa De Oro-Spring Valley area lost power about 8 p.m. Saturday night. But according to SDG&E’s outage map, it was estimated it could take until noon Monday for service to be restored.
Another circuit affecting 1,020 customers in the Campo-Jamul area that went down because of fire damage at 3:55 p.m. Saturday was not expected to come back online until noon Monday as well.
All told, by early evening Sunday, 44 circuits were out in SDG&E’s service territory, affecting a little more than 18,000 customers.
Some of the impacted areas were far from the Valley fire, such as Kensington and Golden Hill near the center of San Diego as well as Pacific Beach, La Jolla, Rolando Village and Spring Valley. Chunks of North County also lost power.
Extreme heat can lead to power line outages. High temperatures drive up energy demand and in order to keep equipment from overloading, circuit breakers may activate to shut off power to some circuits in the SDG&E service territory.
Plus, crews have to inspect lines to make sure they have not been damaged — and if they are, repairs have to be made.
Flex Alert in effect through Monday
Sunday marked the second day of three straight days that the CAISO has issued a Flex Alert, in which electricity consumers across the state are asked to voluntarily cut back on their energy consumption to help make sure a surge in demand does not outstrip energy supplies.
The Flex Alert is in effect from 3 p.m. to 9 p.m. Sunday and Monday.
Measures consumers can take include setting their air conditioning at 78 degrees, holding off on using major appliances like washers and dryers and closing drapes and blinds to keep homes cool.
“Californians should heed CAISO’s warnings and flex their power to shift energy consumption to earlier in the day today, and protect against predicted shortages Sunday and Monday,” Gov. Gavin Newsom said in a statement.
Last Thursday, in anticipation of tight energy supplies, Newsom issued an emergency proclamation that suspended permitting requirements for power plants across the state so they can generate more power.
In addition, the CAISO last Wednesday issued a directive to electricity generators and transmission operators to postpone any maintenance work so that as many lines as possible can be available to maximize transmission capability.
But despite those efforts, grid managers based in Folsom at 6:30 p.m. Saturday had to resort to issuing a Stage 2 Emergency.
CAISO officials said the grid lost about 1,600 megawatts of resources due to wildfires across the state on Saturday disrupting transmission lines.
“If there’s been energy lost on the system anywhere, it impacts the ability of the California ISO to serve the demands on the system,” the CAISO’s Phipps said.
Updates
8:54 p.m. Sept. 6, 2020: This story has been updated to show that power outages had been avoided Sunday.
6:32 p.m. Sept. 6, 2020: This story has been updated to show that a Stage 2 Emergency was declared at 5:55 p.m. Sunday.
6:12 p.m. Sept. 6, 2020: This story has been updated to show an emergency order issued by the U.S. Department of Energy.
5:54 p.m. Sept. 6, 2020: This story has been updated with more information on the status of the Sunrise Powerlink, new information about outages in San Diego County and an explanation of how heat contributes to problems with power lines.
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