​Commercially operational battery energy storage capacity in ERCOT crossed 15 GW at the end of Q1 2026. Twenty new projects totaling 1.1 GW reached commercial operation across the quarter, marking the largest first quarter on record. However, the pace trailed the 1.7 to 2.1 GW per quarter seen through the second half of 2025.

Meanwhile, accelerating withdrawals from the interconnection queue signal that financing conditions are tightening.

​Modo Energy's buildout projection, which applies per-stage historical completion rates to the active queue, reaches 63 GW by 2030. The Q1 2026 forecast sits at 36 GW over the same period. The gap reflects the growing disconnect between queue capacity and commercially viable projects.

​Key takeaways

• ​Commercially operational BESS capacity in ERCOT reached 14.96 GW and 24.6 GWh at the end of Q1 2026 after 1.1 GW of new capacity reached commercial operation across 20 projects, the largest first quarter on record at 2.6 times the previous Q1 record.
• North zone overtook West as the load zone with the most BESS capacity in ERCOT in Q4 2025 and extended its lead in Q1 2026, reaching 4.55 GW versus 4.02 GW. This is the first time a zone other than West has led since the buildout began accelerating in 2022.
• Withdrawals from the interconnection queue after signing an interconnection agreement are accelerating. Twenty-five projects totaling 3.4 GW withdrew in 2025 and early 2026, compared with just seven projects and 937 MW in all prior years combined.
• Completion of a full interconnection study (FIS) is the strongest signal a BESS project will reach commercial operation, with a 65% completion rate for resolved projects at that stage versus 24% at queue entry.
• Queue-implied buildout reaches 63 GW by 2030, but Modo Energy's central forecast projects 36 GW. The gap is widening as revenue compression makes financing more difficult for early-stage projects.

​Ko now has access to our full asset database and projection. Ask it a question for more detail on any of the projects discussed in this report.

​Q1 2026 is the largest first quarter on record for BESS deployment in ERCOT

​1.1 GW of new BESS capacity was deployed in ERCOT during Q1 2026 across 20 assets at 19 sites. This exceeds Q1 2025 by a factor of 2.6. For context, Q1 deployment in 2024 and 2023 totaled 261 MW and 220 MW respectively.

The pace nonetheless represents a deceleration from the second half of 2025, when quarterly deployment ranged from 1.7 to 2.1 GW. Q3 2025 saw the single largest quarter in ERCOT history at 2.1 GW. The 2025 annual report covers the year's full record-setting trajectory.

​The largest site to reach commercial operation in Q1 was Platinum, a 310 MW two-unit site in Fannin County owned and operated by ENGIE. Bypass (208 MW, owned by Aypa Power, with Constellation Energy serving as both QSE and commercial optimizer) and TE Smith (125 MW, owned by Tesla, with Tesla as the commercial optimizer and ENGIE as QSE) were also notable additions. The full list of new projects is available in the interactive map and table below.

​The remainder of this report covers the geographic and duration trends shaping the fleet, the accelerating wave of post-interconnection agreement withdrawals, the milestones that best predict project success, and Modo Energy's queue-implied buildout projection for 2030.

​Modo Energy subscribers get full access to:

• ​The interactive interconnection queue story showing historical milestone throughput and the current pre-IA-dominated pipeline through 2030,
• Per-stage completion confidence rates from full interconnection study through synchronization,
• The complete dataset of post-interconnection agreement withdrawals in 2025 and 2026,
• Modo Energy's central buildout forecast versus the queue-implied 63 GW projection,
• and can download the data behind all of the charts in the article.

Reach out to Clay Tabaku (clay@modoenergy.com) or Brandt Vermillion (brandt@modoenergy.com) to learn more).

​North zone holds the most BESS capacity in ERCOT after overtaking West in Q4 2025

​The geographic distribution of BESS capacity in ERCOT has evened out as other regions have caught up to the original West Texas concentration. North zone overtook West in Q4 2025 and extended its lead in Q1 2026, reaching 4.55 GW versus 4.02 GW. As recently as Q3 2025, West held the largest share at 3.71 GW.