Thanks to rapid clean energy deployment, expansion of battery storage, and strategic efforts to build up emergency reserves, California heads into summer with more resources to meet electricity demand, including the extreme heat conditions experienced in recent years, but California energy leaders are remaining vigilant about ongoing risks.
An annual Summer Energy Reliability Workshop was held on May 2 in the state where officials from the California Energy Commission (CEC), California Public Utilities Commission (CPUC), California Independent System Operator (California ISO), other state agencies and partners in the energy and utilities industry convened to assess readiness for the summer and strategies to manage extreme weather and potential grid challenges.
In a joint news release, the CEC, CPUC and CAISO noted that the state’s grid is better prepared thanks to the following:
• More than 20,000 megawatts (MW) of new clean energy supply have been added since 2021;
• Battery storage capacity statewide, including residential, commercial, and utility-scale installations, has surged past 13,000 MW, up from about 700 MW heading into 2020.
• The Strategic Reliability Reserve, established by legislation after challenges in 2020 and 2021, now provides 4,000 MW of backup resources, including cleaner options like demand response programs and virtual power plants.
• The extension of operations at the Diablo Canyon Power Plant “provides additional capacity during the clean energy transition, providing stability while new renewable resources and storage continue to come online.”
• State energy agencies have improved forecasting, coordination, and operational strategies to better manage complex situations.
• Coordination with regional partners across the west, including the Western Energy Imbalance Market, continue to enhance grid reliability.
Despite periods of extreme heat last year, the state did not issue a single Flex Alert in 2024, demonstrating the effectiveness of recent investment and coordination, the California entities noted.
While California is well-positioned for summer 2025, officials caution that prolonged, Westwide heat events combined with sudden disruptions - such as wildfires impacting transmission lines - could still create tight grid conditions.
"As the fast-moving January wildfires in Los Angeles have shown, the growing volatility and sudden severity of climate-driven extremes continue to challenge expectations and highlight how quickly events can escalate," the news release said.
“California’s grid is better prepared for extreme heat, but when multiple climate-driven events happen at once, the system could be pushed to its limits,” said California ISO Chief Operating Officer and Senior Vice President Mark Rothleder. “That’s why we remain vigilant and continue refining our emergency response playbook in light of new information and changing conditions.”
A combination of such events unfolded in 2022 when wildfires threatened key transmission infrastructure during a prolonged and widespread heatwave. The situation peaked on Sept. 6 when demand in the California ISO system reached its highest mark ever at 52,061 MW as residents across the state attempted to stay cool while temperatures were 10 to 15 degrees higher than average.
Officials also highlighted how consumer engagement is a key factor in grid stability. Programs like Power Saver Rewards and public awareness of peak demand hours have helped reduce strain on the system, reducing the need for Flex Alerts in recent years.
