Jointly owned by Masdar and Igneo Infrastructure Partners, independent power producer (IPP) Terra-Gen’s Lockhart CL I and II battery energy storage system (BESS) projects have reached commercial operations in San Bernardino County, California, US.
The Lockhart CL I ESS project, built alongside the existing Lockhart solar and battery resources, offers 69MW of capacity. The upcoming Lockhart CL II ESS will contribute an extra 59.7MW. The projects have a combined output of 128.7MW and energy storage capacity of 515MWh.
In total, the projects are comprised of 164 lithium-ion (Li-ion) cells and utilise the existing gen-tie line connecting utility Southern California Edison’s Kramer Junction Substation.
The resource adequacy capacity is completely contracted through two long-term resource adequacy agreements with California utility Pacific Gas and Electric (PG&E).
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According to Terra-Gen, the new facility’s construction generated over 115 jobs at peak and involved workers completing more than 85,000 hours during both construction and the transition to operations.
In December, our colleagues at PV Tech reported that Terra-gen closed financing for the 205MW Lockhart III & IV solar PV project.
Lockhart III & IV is located next to the initial two phases of the Lockhart facility, which will have a total of 160MW of solar PV capacity once finished.
Earlier in 2025, Terra-Gen faced potential delays to a project on the US East Coast when the town of Ulster in New York received a request from local officials of the neighbouring town of Hurley to temporarily suspend the permitting process of a 250MW/1,000MWh BESS project under development by the company.
In October 2024, Emirati state-owned clean energy company Masdar closed its acquisition of a 50% stake in Terra-Gen.
The acquisition was initially announced in March of that year, when Masdar revealed it would purchase a 50% stake in Terra-Gen from US investment firm Energy Capital Partners. After the deal with Masdar was finalised, Igneo Infrastructure Partners, a worldwide infrastructure investment manager, kept its remaining 50% stake.
Terra-Gen was the developer of Edwards & Sanborn, a solar PV and BESS complex in California built in multiple phases and featuring 875MWdc solar PV generation capacity and 3,287MWh of battery storage, making it the largest such project in the world when it went online in late 2024.
The Energy Storage Summit USA will be held from 24-25 March 2026, in Dallas, TX. It features keynote speeches and panel discussions on topics like FEOC challenges, power demand forecasting, and managing the BESS supply chain. For complete information, visit the Energy Storage Summit USA website.
