Texas BESS Concentration

Overview

ERCOT Runs the Largest Battery Fleet in the US

ERCOT (the Electric Reliability Council of Texas) added about 6 GW and 11 GWh of batteries at 60 new sites in 2025, its largest year, ending at 13.9 GW. By the end of June 2026 the fleet stood at 16.5 GW and 28.8 GWh. On July 22, 2026 batteries discharged a record 11,980 MW during a record peak-demand day.

Batteries earn from ERCOT's energy-only market and ancillary services, so merchant projects do not need a utility contract. Real-Time Co-optimization plus Batteries (RTC+B), launched Dec 5, 2025, now co-optimizes battery energy and reserves in real time.

Operators

ENGIE Leads a Market Where No Owner Holds a Majority

ENGIE, which bought Broad Reach Power in 2023, held 2.8 GW at the end of 2025, about 20% of the fleet. The top five owners held 47% and the top 10 held 63%.

Geography

North and South Load Zones Hold the Most Capacity, Brazoria Led 2025 Additions

Brazoria County south of Houston drew 16% of 2025 additions, nearly 1 GW across eight sites, on available land and strong interconnection near Gulf Coast load. Bexar County gained its first four-hour batteries in Q2 2026. West Texas batteries in Reeves, Pecos and nearby counties firm wind and solar and serve oil-field and data center load.

Supply Chain

Brookshire Builds Megapacks in Texas While Cells Still Come Largely From China

Tesla began Megapack 3 production at its Brookshire factory in Waller County in August 2026, with 50 GWh of annual capacity. Each Megapack 3 holds about 5 MWh; four form a 20 MWh Megablock. See Tesla Megapack at Brookshire.

Most of the Texas fleet runs on lithium iron phosphate (LFP) cells from Chinese makers such as CATL, BYD and EVE Energy. The 2025 One Big Beautiful Bill Act kept the storage investment tax credit but added prohibited-foreign-entity rules: projects starting construction in 2026 must source at least 55% of material costs outside covered Chinese entities, rising to 75% after 2029. CATL is on the Pentagon's Chinese military companies list.

Constraints

Low Revenues and Queue Withdrawals Are Slowing New Batteries

Battery revenues paced at about $29 per kW-year in early 2026. New queue entries fell to about 14 GW per half-year from a 31 GW peak in the first half of 2025, and a record 13.7 GW withdrew in the first half of 2026. Median time from queue entry to operation rose from 2.3 years for 2021 projects to 4.4 years in 2026.

Nearly all Q2 2026 additions were two hours or longer, as two-hour systems out-earned one-hour systems every month for two years. SB 6 (2025) also has the PUCT (Public Utility Commission of Texas) revisiting transmission cost allocation, which could change battery economics.

Related coverage

Related Coverage

• Rodeo Ranch Energy Storage
• Tesla Megapack at Brookshire
• ERCOT Energy Sovereignty
• Behind-the-Meter Power
• Southern Spirit Transmission
• Roscoe Wind Complex