Southern Power retrofitting 640MWh of battery storage at two California solar power stations

LinkedIn
Twitter
Reddit
Facebook
Email
Image: Southern Power.

US wholesale energy provider Southern Power is adding battery energy storage to two solar sites in California.

Storage will be added to the company’s Tranquillity Solar Facility and Garland Solar Facility, with Southern Power – a subsidiary of the Southern Company – also announcing it has signed 20 year power purchase agreements (PPAs) with Southern California Edison (SCE) for the two sites.

At the 205MW Tranquillity Solar Facility in Fresno County California, a 72MW / 288 MWh energy storage system will be added, whilst at the 200MW Garland Solar Facility in Kern Country a 88MW / 352MWh storage facility will be added.

The energy storage components will provide flexibility to SCE and the California ISO (CAISO), enhancing grid reliability and enabling further renewable energy integration.

This article requires Premium SubscriptionBasic (FREE) Subscription

Try Premium for just $1

  • Full premium access for the first month at only $1
  • Converts to an annual rate after 30 days unless cancelled
  • Cancel anytime during the trial period

Premium Benefits

  • Expert industry analysis and interviews
  • Digital access to PV Tech Power journal
  • Exclusive event discounts

Or get the full Premium subscription right away

Or continue reading this article for free

“These projects will be two of the first co-located solar and storage projects operating in the California market,” said Southern Power president Bill Grantham, adding that the company was excited to be part of the effort to “enhance California’s grid reliability.”

“The addition of these storage resources to our clean energy portfolio is a great strategic fit for our business and will further position Southern Power to meet our customers’ needs as the energy industry continues to evolve.”

Both energy storage projects will be owned in partnership with AIP Management and Global Atlantic Financial Group, who already have existing ownership interests in the two facilities. Southern Power will be responsible for operating the storage, building on their operation of both solar sites since they went into commercial operation in 2016.

This story first appeared on PV Tech.

6 October 2026
Warsaw, Poland
The Energy Storage Summit Central Eastern Europe is set to return in September 2025 for its third edition, focusing on regional markets and the unique opportunities they present. This event will bring together key stakeholders from across the region to explore the latest trends in energy storage, with a focus on the increasing integration of energy storage into regional grids, evolving government policies, and the growing need for energy security.
3 November 2026
Málaga, Spain
Understanding technology and supplier selection for Europe’s utility-scale PV market in 2027. PV ModuleTech Europe 2026 is a two-day conference that tackles these challenges directly, with an agenda that addresses all aspects of PV module, inverter and battery supplier selection; product availability, technology offerings, supply chain traceability, quality assurance, factory auditing, system reliability, and supplier bankability.

Read Next

October 2, 2026
India’s Union Cabinet has approved US$ 19.3 billion Green Energy Corridor, including US$ 5.2 billion for 50GWh BESS through FY2032-33.
October 2, 2026
Outgoing California Governor Gavin Newsom recenty addressed approximately 1,200 bills, including several energy storage and solar related bills that were either approved or vetoed.
October 2, 2026
Fu-Gen has sold a 100MW ready-to-build battery storage project in Finland to Nala Renewables, extending their Nordic BESS pipeline to 275MW.
October 2, 2026
NSW’s IPC has approved BayWa r.e.’s Bullawah Wind Farm, pairing 804MW of wind with a 718MWh battery in the South West REZ.
October 1, 2026
Energy-Storage.news spoke with Noemí Gallardo, Commissioner at the California Energy Commission (CEC), at the US Solar & Storage Finance event in Garden Grove, California, about the growth of BESS within the state.