California’s new 1,000 MWh energy storage facility can deliver 250 MW for four hours

Arevon Energy is building a 250-megawatt/1,000-megawatt-hour battery storage facility in Daly City, California, designed to send power to the grid during periods of peak demand. The Cormorant Energy Storage Project is expected to begin operations in 2027. The project can store electricity when demand is lower and discharge it when demand rises. Arevon says the facility will be capable of powering about 321,000 homes for up to four hours. The project uses lithium iron phosphate (LFP) battery technology, a chemistry widely used in large-scale energy storage because of its long operating life and safety characteristics. Construction began in March 2026, and the project has now reached a significant construction milestone. Arevon is developing, owning and operating Cormorant in partnership with Primoris Services Corporation’s Renewables group. Battery storage fills gaps Cormorant is being built to help California manage periods when electricity demand is high but generation from sources such as solar power is falling. The facility’s 1,000 MWh capacity means it can deliver 250 MW of power continuously for up to four hours. That makes it a four-hour energy storage system, allowing electricity generated or purchased during lower-demand periods to be held and dispatched later. “Cormorant represents the kind of critical energy infrastructure California needs to meet growing electricity demand while strengthening grid reliability,” said Johnson. “This event recognized the tremendous work of our construction crews and project partners who are bringing this facility to life. Arevon is proud to invest in projects that store power when it is abundant, deliver it when it is needed most, and support a more reliable and affordable energy future for California.” The project is also larger than originally planned. Cormorant was initially designed as a 188 MW/752 MWh system before being expanded to 250 MW/1,000 MWh. MCE, an electricity provider serving more than 1.8 million residents and businesses across several California counties, has signed a long-term offtake agreement for the project. The provider contracted for the additional capacity created by the expansion. California adds storage capacity The project is part of California’s broader push to add battery storage as electricity demand grows and the state integrates more renewable generation. “The CPUC expects over 20 gigawatts of new clean resources to come online by 2032 to meet our reliability requirements. Battery storage is a critical part of that effort, providing reliability when solar generation declines and demand remains high,” said Molly Sterkel, a director in the Energy Division of the California Public Utilities Commission. Cormorant is also expected to provide economic and environmental benefits to Daly City. Arevon estimates the project will generate more than $73 million in property tax revenue over its lifetime, supporting schools, infrastructure and public services. The company says the facility will save more than 4.2 billion gallons of water and avoid about 174,000 metric tons of carbon dioxide emissions annually. Around 175 workers are expected to be employed at the project’s peak construction phase. MCE will also distribute more than $500,000 for local community programs under its agreement with Arevon. The funding is intended to support programs in the surrounding community. Once operational, Cormorant will add another large battery system to Arevon’s California portfolio. The company already operates projects including the 300 MW Nighthawk Energy Storage Project and the 200 MW Peregrine Energy Storage Project, along with solar-plus-storage facilities.For Cormorant, the central function remains straightforward: store electricity when the grid has more power available and release it when the system needs additional supply. The facility is expected to enter commercial operation in 2027.Get the latest in engineering, tech, space & science - delivered daily to your inbox.With over a decade-long career in journalism, Neetika Walter has worked with The Economic Times, ANI, and Hindustan Times, covering politics, business, technology, and the clean energy sector. Passionate about contemporary culture, books, poetry, and storytelling, she brings depth and insight to her writing. When she isn’t chasing stories, she’s likely lost in a book or enjoying the company of her dogs.