SMT Energy and FlexGen Start Up a 160 MW / 320 MWh Houston Battery One Quarter Past Target
- Energy Storage News Utility-Scale BESS
Marin Holt
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- 7 minutes read
- Capacity: 160 MW / 320 MWh
- Location: Houston, Texas (ERCOT)
- Commissioning time: six weeks
- Original target: Q2 2026
- Groundbreaking: May 2025
SMT Energy and storage integrator FlexGen announced the start of operations at SMT Houston IV on September 9, 2026. The plant is a 160 MW / 320 MWh battery energy storage system in Houston, Texas. The site will sell into the ERCOT wholesale market and supply ancillary services. Irby Construction Company served as the EPC contractor. The project is one of more than 12 that SMT and FlexGen have built for the ERCOT grid.
SMT and FlexGen said they commissioned the plant in six weeks. They described that as “cutting the time of deployment by 3x from the original timeline.”
Six Fast Weeks at the End of a Long Project
The six-week figure covers commissioning, not the project. SMT closed financing on Houston IV in February 2025. It told the market then that it targeted commercial operation in the second quarter of 2026. SMT and utility CenterPoint Energy broke ground in May 2025. Operations started in September 2026, one quarter after that target and about 16 months after groundbreaking. A faster final phase did not make the project early.
SMT’s February 2025 announcement described a US$100 million project financing facility arranged by Macquarie Group and KeyBanc Capital Markets, alongside investment tax credits. FlexGen supplied the equipment and runs the site on its HybridOS energy management software.
Why It Matters
Dividing 320 MWh by 160 MW gives a two-hour battery. That duration suits ERCOT ancillary services and short peak events, and it rules the site out of multi-hour load shifting. Developers sizing Texas projects should read Houston IV as a bid on the ancillary and real-time markets rather than on long-duration arbitrage.
The six-week commissioning number is the part worth borrowing. Commissioning is where ERCOT projects stall, because it depends on the utility, the ISO and the integrator at once. If SMT and FlexGen repeat it across their other ERCOT sites, the saving lands in revenue rather than in a press release. Watch whether their next project beats its own stated commercial-operation date, which Houston IV did not.
SMT puts the site at the annual consumption of 8,800 Texas homes. That is a throughput claim across a year of cycling, not what one discharge delivers. Read it as marketing arithmetic.
Critical Perspective
The six-week number has no published denominator. SMT and FlexGen call it 3x faster than “the original timeline.” Neither company states what that original commissioning window was, or when the six weeks started. A multiple without its base is a claim, not a measurement.
The schedule also cuts the other way. The Q2 2026 target came from SMT’s own February 2025 announcement, and operations began in September 2026. Neither company has said what consumed the extra quarter. Fast commissioning fits a team recovering lost schedule, which is a different achievement from beating a plan.
“More than 12” ERCOT projects is the partners’ own count. No list of those sites appears in the announcement, so anyone tracking FlexGen’s integration record has nothing to check it against.
The two-hour duration is the open question for revenue. SMT aims Houston IV at ancillary services, which is where ERCOT batteries have already crowded in. If those prices compress further, a two-hour asset has less room to shift into energy arbitrage than a four-hour one. The 8,800-homes figure also predates operation. It comes from the February 2025 financing release, not from dispatch data.
Sources
- Energy-Storage.news: FlexGen, SMT Energy commission 320MWh Texas BESS in just six weeks, as ERCOT grid faces record demand (September 10, 2026)
- SMT Energy via PR Newswire: SMT Energy Secures US$135 Million for 320 MWH Battery in Houston (February 26, 2025)
- Energy-Storage.news: SMT Energy breaks ground on 320MWh Texas BESS (May 2025)
- Mercom Capital Group: SMT Energy Secures Funding for 160 MW/320 MWh Energy Storage Project
