B2U Storage Doubles ERCOT Footprint With Second Second-Life Battery Project Near San Antonio
The 28-MWh Bexar Martinez installation in CPS Energy territory adds to a wave of short-duration storage competing for ERCOT's arbitrage stack.
B2U Storage Solutions brought its 28-MWh Bexar Martinez battery energy storage installation into commercial operation in CPS Energy's service territory near San Antonio, the California-based company said the week of September 7 (2026-09-07). The project is B2U's second Texas second-life energy storage system to reach commercial operations, and the company has indicated further projects are in development.5
ERCOT's battery fleet skews heavily toward short durations. ACP data show online battery projects in the grid average just 1.6 hours of storage duration, below comparable figures in other US states, reflecting an energy-only market structure that rewards fast response and ancillary-service revenue over sustained multi-hour discharge. Second-life assemblies — repurposing battery packs from earlier applications at lower upfront cost than virgin cells — are well suited to that profile.4
B2U's repeat presence in ERCOT arrives alongside a broader wave of larger-scale storage investment. Spearmint Energy in May 2026 closed a $450 million financing package for Red Egret, a 300-MW/600-MWh standalone BESS in Texas City southeast of Houston, targeting commercial operations in 2027. The deal included $96 million of preferred equity from Nuveen Energy Infrastructure Credit and roughly $126 million of proceeds from an investment tax credit transfer commitment.2,1
Spearmint already operates 350 MW/700 MWh of BESS within ERCOT, and Red Egret would push its total operating capacity beyond 1.5 GWh across four projects. The financing structure, leaning on ITC transfers alongside equity rather than conventional project debt, reflects how much federal tax credit policy continues to underpin merchant storage economics in Texas despite the absence of a capacity market.2
The economics of second-life projects differ materially. By sourcing modules from retired battery packs, developers like B2U target a lower per-MWh capital cost than greenfield lithium-iron-phosphate installations. The source material does not specify B2U's cell sourcing or unit economics at Bexar Martinez, making a direct cost comparison with projects such as Red Egret unavailable from current data.5
Two projects now operating in ERCOT indicate that B2U has worked through the interconnection and permitting sequence that still delays many storage developers in Texas. The CPS Energy context matters separately: as a municipally owned utility serving greater San Antonio, CPS has its own resource-planning and procurement processes, offering storage developers a different commercial structure than the purely merchant exposure that most large ERCOT operators carry in competitive zones where real-time price signals drive every dispatch decision.5
The storage wave entering ERCOT will compete for the same ancillary-service and real-time arbitrage stack. Short-duration assets concentrate revenue in high-volatility price intervals. As more capacity enters a grid designed around energy-only pricing, the incremental value of each new megawatt-hour of storage tends to compress unless load growth and peak-price volatility keep pace with the buildout.4
On the supply side for battery cells, CATL has said it expects energy storage to account for half of its global sales by 2030, up from 25% currently. Sustained cost decline at that scale would improve project economics for both greenfield and second-life operators, though for second-life assemblers the benefit depends on how resale values of retired EV packs track against new-cell prices as the market matures.3
B2U has not publicly disclosed the scale or timeline of the subsequent ERCOT projects mentioned in its announcement. Whether those installations remain in the sub-50 MWh range of Bexar Martinez or step up toward utility scale will indicate how aggressively the company intends to compete in a market already attracting nine-figure financings from larger developers.5