As a record-breaking heatwave stressed California’s power grid in early September, energy experts scrambled to avoid blackouts. Around 5pm on Sept. 6, the governor’s office and California Independent System Operator (ISO) sent an emergency text alert to people around the state. The response saved the grid, but it’s no long-term solution.
“With historic high temperatures in all parts of the state, electricity use on the ISO grid hit a peak Tuesday of 52,061 megawatts, breaking a record previously set in 2006,” ISO spokesperson Anne Gonzales wrote in an email. “Conservation was key to reducing demand on the system at the critical time of need.”
In addition to the emergency text, CAISO issued Flex Alerts for several days, calling for users to conserve electricity voluntarily.
“We know that it was difficult for Californians to lower electricity use, especially during historic heat, for 10 straight days of Flex Alerts,” said Gonzales. “But reducing demand in the late afternoon and evening when temperatures remain high and solar production is rolling off the system was vital to keeping electricity flowing.”
The alerts helped avoid something worse than rolling blackouts: a collapse of the grid.
“The last time that happened in California was in 2011 in San Diego, when there was a trip on the line coming from the east out of Imperial, and they lost everything,” says V. John White, the co-founder and executive director of the Center for Energy Efficiency and Renewable Technologies. The Sacramento-based coalition of companies and nonprofits has focused on renewable energy policy for more than 30 years.
When a grid collapses, it must be brought back slowly in a process called a black start. Regaining power can take several days.
“I think the main lesson to take from our experience [this month] is how valuable and important a flexible load and demand response turned out to be,” says White. “Without the voluntary response of millions of citizens, there’s every likelihood that we wouldn’t have made it on that Tuesday.”
Shifting peak energy use to different times of day helps, and White believes compensating customers for the shift should be part of the future strategy.
“There’s more that we could do if we were willing to pay customers to move their load around,” he says. “And hopefully that’s one of the lessons that will come from this year’s experience.”
In a grid update from Sept. 9, ISO CEO and President Elliot Mainzer called the conditions “a historic unrelenting heat storm.”
It broke records in several areas. Sacramento reached 116 degrees, San Jose hit 109 degrees, and parts of the Santa Cruz Mountains stayed in the 90s overnight. But while historic, the heat wave will likely not be the last of its kind.
“We’re adapting to really profound and serious changes in the climate on the fly,” says White.
Santa Cruz is attempting to address those changes by sourcing cleaner energy through Central Coast Community Energy (3CE) and Pacific Gas and Electric Company (PG&E) projects. But complications make the process slow, and changing the grid comes with new challenges.
Last week, commuters and residents witnessed one such challenge as a battery pack fire at a PG&E substation in Moss Landing closed Highway 1 and resulted in a temporary shelter-in-place order. The battery megapacks were commissioned by Tesla for a PG&E energy storage system in April.
Burning lithium-ion batteries can result in the release of toxic chemicals, so authorities shut the area down for several hours. The cause of the fire is under investigation.
Despite the potential setbacks, batteries were one important element in keeping the grid intact earlier this month.
“We got 3,300 megawatts of batteries that were online, and they really helped fill in the gaps,” says White. He notes that further diversifying the grid could help make the system more resilient.
“We can’t just have solar and batteries,” he says. He adds that geothermal and imported wind energy from New Mexico and Wyoming should be part of California’s energy portfolio, in addition to helping customers change the demand.
“I’m optimistic that we can run the grid and keep the lights on and reduce our fossil fuel use, but we’ve got to get good at it,” says White. “We’ve got to pay attention, and we’ve got to make adjustments. And hopefully, that’s what we’ll do.”