California solar-plus-storage project with world’s largest BESS fully online

January 24, 2024
LinkedIn
Twitter
Reddit
Facebook
Email

The Edwards & Sanborn solar-plus-storage project in California is now fully online, with 875MWdc of solar PV and 3,287MWh of battery energy storage system (BESS) capacity, the world’s largest.

The 4,600-acre project in Kern County is made up of 1.9 million PV modules from First Solar and BESS units from LG Chem, Samsung and BYD totaling 3,287MWh of energy storage capacity.

That makes it bigger than the current largest BESS in the world, Vistra’s 750MW/3,000MWh facility at Moss Landing, also in California, which also came online in two phases.

It has now reached ‘substantial completion’ and is ‘fully online’, Mortenson said this week. Energy-Storage.news has asked Mortenson and project owner Terra-Gen what ‘substantial completion’ means and will update this article if and when a response is received.

This article requires Premium SubscriptionBasic (FREE) Subscription

Enjoy 12 months of exclusive analysis

Not ready to commit yet?
  • Regular insight and analysis of the industry’s biggest developments
  • In-depth interviews with the industry’s leading figures
  • Annual digital subscription to the PV Tech Power journal
  • Discounts on Solar Media’s portfolio of events, in-person and virtual

Or continue reading this article for free

Engineering, procurement and construction (EPC) contractor Mortenson started construction around three years ago and the first phase, comprising about half of the total capacity, came online in late 2021.

The project has an interconnection capacity of 1,300MW. Its offtakers include the city of San Jose, utilities Southern California Edison (SCE) and Pacific Gas & Electric (PG&E), community choice aggregator (CCA) Clean Power Alliance, and coffee chain shop Starbucks.

Although the MW power of the BESS has not been revealed, most BESS projects in California are 4-hour duration (to qualify for grid operator CAISO’s Resource Adequacy framework) which would make this BESS 821MW.

Part of the project is located on the Edwards Air Force Base and Mortenson said the project was the largest public-private collaboration in US Department of Defense history.

“Now fully operational, this facility is a transformational project in the industry and is providing resiliency to the grid,” said Brian Gorda, VP of engineering at Terra-Gen. 

Terra-Gen’s other notable energy storage project is the 140MW/560MWh Valley Center BESS, also in California, though that project was in the headlines in 2023 for the wrong reasons (including a battery fire and a theft of decommissioned batteries).

Energy-Storage.news’ publisher Solar Media will host the 5th Energy Storage Summit USA, 19-20 March 2024 in Austin, Texas. Featuring a packed programme of panels, presentations and fireside chats from industry leaders focusing on accelerating the market for energy storage across the country. For more information, go to the website.

11 November 2025
San Diego, USA
The 2024 Summit included innovative new features including a ‘Crash Course in Battery Asset Management’, Ask-Me-Anything formats and debate-style sessions. You can expect to meet and network with all the key industry players again in 2025 from major US asset owners, operators, RTOs and ISOs, optimizers, software and analytics providers, technical consultancies, O&M technology providers and more.

Read Next

October 17, 2025
Utility and power firm Naturgy has started building its first BESS projects in Spain, at four solar PV plants in Almeria and the Canary Islands.
October 17, 2025
Powerlink Queensland is seeking federal approval for transmission infrastructure connecting AGL Energy’s 2,000MWh Tuckeroo battery energy storage system (BESS) to the Western Downs Substation in Australia.
October 17, 2025
The New South Wales Independent Planning Commission has approved Ark Energy’s 3,148MWh Richmond Valley solar-plus-storage project in Australia.
Premium
October 16, 2025
Utility-scale developer SB Energy has received a US$25 million grant from the California Energy Commission (CEC) to purchase BESS units for one of its solar and storage hybrid complexes located in Riverside County, California. 
October 16, 2025
Fluence has announced a solar-plus-storage project in Arizona, while Greenflash Infrastructure adds to its Texas BESS portfolio.

Most Popular

Email Newsletter