Spearmint Energy said on May 12, 2026 that it has reached commercial operation on two utility-scale battery energy storage systems in Texas, adding a combined 200 MW / 400 MWh of capacity to the ERCOT grid.
The Projects
The 100 MW / 200 MWh Tierra Seca project in Del Rio and the 100 MW / 200 MWh Seven Flags project in Laredo were both energized in late December 2025 and have now completed roughly six months of operational data. They use Sungrow’s PowerTitan 2.0 liquid-cooled platform, which integrates a 5 MWh battery with a 2.5 MW power conversion system in a 20-foot container.
How It Was Financed
Spearmint secured roughly $250 million in financing for the two projects in April 2025, including a $59 million construction-to-term loan from Manulife, $95 million in tax equity bridge loans from East West Bank and Investec, and $98 million in tax equity from Sugar Creek Capital. EPC firm Mortenson led construction.
Strategic Backdrop
The projects originally traced back to a 2022 exclusivity deal between Black Mountain Energy Storage and Cypress Creek Renewables; Spearmint has not disclosed how it acquired them. In January 2026, Spearmint brought in Kyuden International, the overseas arm of Japan’s Kyuden Group, as an equity partner in the projects — Kyuden’s first U.S. BESS investment. For broader context, see our coverage of Moment Energy’s $40M second-life battery factory and Pure Lithium’s 500 MWh solid-state output milestone.
What To Watch
Tierra Seca and Seven Flags arrive as ERCOT’s storage fleet pushes past historic peaks and as developers race to lock in interconnect queue positions ahead of further policy changes. Spearmint has signaled additional Texas projects on its development pipeline.
Reporting based on coverage from Spearmint Energy and Energy-Storage.News.