Sandrini Energy Storage Adds 92 MW of Battery Capacity Beside 300 MW California Solar Site

EDP Renewables North America and Redwood Coast Energy Authority announced on August 18, 2026, that Sandrini Energy Storage has been completed in Kern County, California, adding a 92 MW/368 MWh battery system beside the 300 MW Sandrini Solar site. The four-hour battery expands California’s dispatchable storage fleet and is designed to shift electricity into periods when demand and grid needs are higher.

Redwood Coast Energy Authority has an energy storage service agreement covering 100% of the battery’s capacity, while the community choice aggregator also purchases 100 MW from the adjacent solar project. EDP Renewables said the battery has the capacity to supply electricity equivalent to more than 22,000 California homes, although that comparison is an energy-equivalence metric rather than a claim that the project directly serves those households.

The battery adds four hours of storage to the Sandrini site

The 92 MW power rating and 368 MWh energy rating give Sandrini approximately four hours of storage at its maximum rated output. That allows the facility to charge when electricity is available and discharge later as system conditions require.

EDP Renewables and Redwood Coast Energy Authority said in the completion announcement that the project is intended to strengthen grid reliability and help deliver renewable electricity when it is most needed.

The storage facility sits alongside the 300 MW Sandrini Solar Energy Park. RCEA purchases 100 MW from the solar project, while Shell Energy North America purchases electricity from its other 200 MW phase.

EDP Renewables commissioned both phases of Sandrini Solar in the fourth quarter of 2024, establishing the generation component before the latest storage milestone.

RCEA contracted for the full battery capacity

The commercial foundation for Sandrini Energy Storage predates the completion announcement. EDP Renewables disclosed in 2024 that it had secured a 15-year energy storage service agreement with RCEA covering the 92 MW/368 MWh battery.

EDP’s original storage agreement announcement said Sandrini could charge using either solar production or electricity from the grid. That flexibility means the battery is not limited to storing generation from the neighboring solar array.

RCEA is a local government joint powers agency serving Humboldt County. Its members include the County of Humboldt, seven incorporated cities, the Blue Lake Rancheria and the Yurok Tribe.

The authority has been expanding its portfolio of storage and renewable resources as California load-serving entities procure additional capacity to meet reliability requirements and reduce dependence on electricity during the most constrained hours.

Solar and storage can serve different parts of the daily demand curve

Co-locating battery storage with solar can increase the operational value of a renewable-energy site because the two assets do not have to deliver electricity at the same time.

Solar production typically reaches its strongest levels during daylight hours. Battery storage can absorb electricity and return it to the grid later, including during evening periods when solar production declines while electricity demand remains elevated.

That does not make intermittent solar generation continuously available without limitation. Sandrini’s 368 MWh energy rating defines how much electricity the battery can store, while its 92 MW rating defines the maximum discharge power.

The project also illustrates how California’s storage buildout is increasingly being paired with existing or newly constructed renewable generation rather than developed solely as standalone batteries.

The project adds to EDP Renewables’ California storage portfolio

EDP Renewables said its California operating portfolio now includes approximately 1,230 MW of gross wind, solar and energy-storage capacity. The company also operates the Scarlet Solar Energy and Energy Storage project in Fresno County and has developed battery projects elsewhere in the western United States.

Federal Energy Regulatory Commission asset records identify Sandrini BESS Storage LLC as a 92 MW generating asset in the California ISO region, providing an additional regulatory record for the project’s rated power capacity.

Beyond its energy role, EDP Renewables estimates the battery will generate more than $5 million in revenue supporting local public services and infrastructure. Approximately 50 construction jobs were associated with the storage project, while the combined Sandrini solar and storage development supported approximately 250 construction jobs, according to the company.

What happens next

The completion milestone moves Sandrini from development and construction into the operating portfolio. Its performance will now depend on dispatch decisions, market conditions and RCEA’s contracted use of the storage capacity.

For California grid planners, Sandrini adds another four-hour battery resource capable of shifting electricity across the day. For RCEA, it adds contracted storage that can complement the solar capacity the authority already purchases from the same renewable-energy complex.

Jonas Muthoni

Jonas Muthoni is Editor-in-Chief of Microgrid Media, where he oversees reporting and analysis on microgrids, energy storage, distributed energy resources, data center power demand, grid modernization, resilience, renewable energy, and electricity policy and markets. His work focuses on the infrastructure, technologies, and regulatory developments reshaping the power system.

As Editor-in-Chief, Jonas leads Microgrid Media’s editorial strategy and standards, including story selection, source verification, technical accuracy, and the development of original reporting and analysis. His coverage draws on regulatory filings, government records, utility and company disclosures, technical documentation, and independent industry sources to explain significant developments across the evolving energy system.