Tesla Megapacks Power Ørsted's Old 300 Texas Battery
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- Tesla Megapacks are now supporting the ERCOT grid at Ørsted's new 250 MW/500 MWh Old 300 battery storage project in Needville, Texas (southwest of Houston), with full output delivering 250 MW of power for two hours.
- The Megapacks were built at Tesla's Megafactory in Lathrop, California — described as the largest industrial utility-scale BESS factory in the US.
- Each Tesla Megapack arrives pre-integrated with battery modules, inverters, thermal management, and controls; the current two-hour configuration provides roughly 1.9 MW of power and 3.85 MWh of storage per unit.
- Old 300 Storage sits adjacent to Ørsted's 430 MW Old 300 Solar, but the two operate independently — the battery draws from and feeds the wider ERCOT grid rather than just the neighboring solar farm.
- Old 300 Solar, operating since 2024, generates enough power annually for around 80,000 Texas homes and businesses; together with the new BESS, the projects are expected to deliver roughly $110 million in property tax revenue for local schools, infrastructure, and emergency services.
- The 500 MWh deployment expands Ørsted's US onshore operating portfolio to about 6 GW; Tesla says it now has more than 58 GWh of industrial storage systems operating across 65+ countries.
Why it matters: This adds another 500 MWh to Tesla's stationary storage business while expanding Ørsted's US onshore renewable footprint to roughly 6 GW, reinforcing ERCOT's battery fleet at a time when extreme weather and climbing demand have repeatedly stressed Texas grid margins. The colocation-without-coupling design — a battery sitting next to a solar farm but wired to the wider grid — signals that grid-scale storage is increasingly being valued as a standalone ERCOT asset, not a solar afterthought.
