How well California has planned its push to convert its electricity grid to zero-emissions energy could be revealed in the next five years.
Within that time, the state plans to bid farewell to major sources of round-the-clock power, like nuclear and natural gas, and see thousands of electric vehicles plug in to charge and more cities adopting all-electric standards for new homes.
And that would come about as 6,000 megawatts (6 gigawatts) of in-state dispatchable electricity production capacity, or about 7% of all California sources, are set to be retired by 2026, according to the California Energy Commission. That includes such produce-on-demand sources such as natural gas plants that can increase or decrease production based on how much residents and businesses are using at any given time.
And in 2025, the state’s last nuclear power plant, Diablo Canyon on the Central Coast, is set to go off line permanently when its licenses expire under a legal settlement with environmental groups. It’s twin reactors, totaling 2.5 megawatts, produced 8.5% of California’s electricity last year but account for 43% of Pacific Gas & Electric Co.’s power supply for Central and Northern California.
Meanwhile, Sacramento legislators and regulators have been upping the ante. They bet that California can move to 60% renewable energy by 2030 and 100% by 2045. That includes plans to move away from internal combustion engines. The goals are part of a statewide effort in the past two decades to reverse emissions of gases blamed for changing the climate and increasing the frequency and severity of wildfires.
“We’ve been planning for this since 2015 and in a concerted way with harder targets since 2020,” said Geof Syphers, CEO of Sonoma Clean Power, a community choice aggregation utility that serves upwards of 230,000 customers in Sonoma and Mendocino counties. “There is some risk that not all these resources will get built on time.”
Such CCAs have roughly 60% of the energy customer accounts in Northern and Central California, while PG&E has 40% but handles power transmission for those areas.
Planning to meet the lofty goals, in June, the California Public Utilities Commission called on suppliers to the California Integrated System Operator-managed grid to bring on line at least 11,500 megawatts of additional net qualifying capacity from zero-emissions sources paired and the battery capacity to store it over the next five years: 2,000 megawatts in 2023, 6,000 in 2024, 1,500 in 2025 and 2,000 in 2026. That’s on top of 1,070 and 1,505 megawatts called for in a 2019 commission decision. Overall, the state hopes to increase generating capacity by just over 13,000 additional megawatts by 2026.
Net qualifying capacity is a metric that energy planners can use to compare how various sources will contribute to meeting demand over the day. A California Energy Commission mid-term reliability analysis released in September on the CPUC decisions found that 43 megawatts of nameplate solar capacity — the stated size of the system at installation — would be required to equal 1 megawatt of net qualifying capacity in 2022 and 53 megawatts would be necessary by 2026. Wind power would require 3.5 megawatts of rated capacity per 1 megawatt that could be used in planning.
The energy commission report found that about 10,000 nameplate megawatts of battery storage would be needed by 2026, allowing energy produced during peak solar and wind hours to be stored and discharged during peak demand times. Battery energy storage systems, or BESS, plugged into the Cal ISO grid grew from 550 megawatts at the end of last year to 1,500 megawatts last month and an estimated 3,000 megawatts by the end of this year, according to the energy agency.
“Reliability in the mid-term and beyond will be highly dependent on BESS deployment at a sustained rate and BESS operational performance,” the report said.
The report noted that 20% of the planned battery installations statewide could be delayed by as much as a year because of supply-chain issues. And ongoing testing of battery systems continues to ensure safety and reliability.
On Sept. 4 at Vistra’s Moss Landing Energy Storage Facility in Monterey County, said to be the world’s largest such battery installation, the 300-megawatt phase 1 went offline when the batteries overheated, scorching the power cells and melting wiring, according to the report. Phase 1 went online in December, and another 100 megawatts was added in phase 2 in August.
The energy agency’s report concludes after modeling various scenarios including outages, less solar and wind production than forecast, and less electricity available to import into the state that California can weather the transition to clean energy without the rolling blackouts of August 2020 or resorting to emergency measures as Gov. Gavin Newsom authorized this summer, including running ship engines at port or generators at hospitals to cover peak demand.