Texas's electrical grid got a significant new buffer this week. On August 5, 2026, Ørsted's Old 300 Storage project in Needville, Texas reached commercial operations — a 250 MW / 500 MWh battery energy storage system built entirely with Tesla Megapacks and now fully integrated into the ERCOT grid.
The project is co-located with the existing Old 300 Solar facility, a 430 MW solar farm that has been operating since 2024 and generates enough electricity annually to power approximately 80,000 Texas homes and businesses. The two projects share a site but operate independently — the battery can charge from any source on the ERCOT grid and dispatch when prices spike or supply tightens.
Project Specifications at a Glance
| Parameter | Value |
|---|---|
| Commercial operations | August 5, 2026 |
| Location | Needville, Texas (southwest of Houston) |
| Grid connection | ERCOT |
| Power capacity | 250 MW |
| Energy capacity | 500 MWh (2-hour discharge duration) |
| Battery hardware | Tesla Megapack (1.9 MW / 3.85 MWh per unit) |
| Manufacturing site | Tesla Megafactory, Lathrop, California |
| Co-located project | Old 300 Solar, 430 MW (operational since 2024) |
Why Texas Needs Storage Like This
ERCOT is the most battery-dense grid in the United States, and it's adding capacity at a pace that reflects hard lessons from the February 2021 winter storm and repeated summer scarcity events. The U.S. Energy Information Administration projects that Texas will add 12.9 GW of new utility-scale battery storage in 2026 alone — more than half of the entire country's planned storage additions for the year.
"Battery energy storage has played a large role in providing much-needed power to ERCOT in times of tight supply." — Melissa Peterson, President of Ørsted Americas Onshore
Old 300 Storage will earn revenue primarily by discharging during afternoon and evening peak demand periods — the same windows when solar output falls and grid prices climb. At full output, the system can deliver 250 MW for two hours continuously, enough to supply roughly 200,000 average Texas households during a peak demand event.
Tesla Megapack's Grid Scale
Old 300 Storage uses the Megapack in its current-generation 1.9 MW / 3.85 MWh configuration. Each unit was manufactured at Tesla's Megafactory in Lathrop, California — currently the largest industrial utility-scale battery factory in the United States by output — before shipping to Needville for installation.
Tesla now operates 58+ GWh of industrial energy storage across 65+ countries, and the Brookshire, Texas Megafactory that came online August 6 will supply next-generation Megapack 3 units (5 MWh per cabinet) into the deployment pipeline. The combined ERCOT and broader U.S. grid backlog suggests Ørsted-scale deployments will become more frequent, not less.
Old 300 Storage is expected to generate approximately $110 million in local property tax revenue over the project lifetime — a figure that reflects the scale of capital required for grid-level battery infrastructure and the growing willingness of Texas counties to attract it.
The Bottom Line for the ERCOT Grid
A single 500 MWh project does not solve Texas's grid reliability challenges on its own — ERCOT's peak demand routinely exceeds 80,000 MW. But Old 300 Storage is part of a wave. As interconnection queues clear and new battery projects reach commercial operations through 2026 and 2027, the grid's ability to absorb renewable generation swings and handle summer peak demand will fundamentally improve. Tesla Megapack is, by deployment volume, at the center of that buildout.
Photo: Industrial energy facility / Pexels