Tesla's grid battery business has a new factory and a new product line running through it. On 6 August 2026 the company confirmed that the first Megapack 3 units are rolling off the line at its newest Megafactory in Brookshire, Texas, west of Houston. Tesla says the site went from groundbreaking to production in 16 months and is designed to build 50 GWh of Megapack 3 a year.
For a division that has spent two years supply-constrained rather than demand-constrained, that number is the story.
What Megapack 3 actually is
Each Megapack 3 delivers roughly 5 MWh of AC energy. Electrek reports the new unit packs about 28% more energy into the same footprint as the Megapack it replaces — a figure Tesla has not published in its own materials, so treat it as reporting rather than spec.
The more consequential change is how the units are sold. Four Megapack 3 cabinets combined with a transformer and switchgear form a Megablock: a single 20 MWh delivery instead of a site full of individually wired cabinets. Tesla says the integrated approach cuts on-site installation time by 23% and construction costs by 40%. Megablock deliveries are scheduled to begin in the second half of 2026.
That is a deployment-speed play, not an energy-density play. Grid storage projects are increasingly bottlenecked by electricians, interconnection queues and commissioning time rather than by cells.
Why this lands in Europe
Europe installed 36 GWh of new battery storage in 2025, and annual deployments are forecast to pass 50 GWh in 2026 and reach 138 GWh by 2030. Italy and the UK are two of the continent's three largest storage markets — which is precisely where Tesla's largest European order sits.
| Project | Market | Scale |
|---|---|---|
| NatPower framework | Italy and UK | 25 GWh |
| Mufasa | Netherlands | 372 Megapacks, 1.4 GWh |
| TagEnergy, Marne | France | Country's largest BESS to date |
| Ørsted Old 300 | Texas, US | 250 MW / 500 MWh |
The NatPower agreement signed in June 2026 is the largest European Megapack deal Tesla has struck. To put its scale in context, filling the first 25 GWh phase from Tesla's Lathrop, California plant alone would consume more than 60% of that factory's roughly 40 GWh annual output. Brookshire is what makes that order book deliverable without starving every other market.
The part that is easy to miss
Tesla deployed a record 13.5 GWh of storage in the second quarter of 2026, up from 9.6 GWh a year earlier — roughly 41% growth. Vehicle deliveries grew about 25% over the same period, to 480,126 cars. The energy business is now compounding faster than the car business that funds it.
European buyers do not order a Megapack, and none of this changes what a Model Y costs in Munich. But grid-scale storage is what lets a grid absorb cheap midday solar and hand it back at 7pm, and that is the mechanism that eventually shows up in an overnight home charging tariff. A factory dedicated to shipping 50 GWh a year of it is worth noticing.
What Tesla has not said is how Brookshire's output will be split between North American and European projects. Until it does, the 25 GWh Italian and British order book remains a commitment against capacity that is only now coming online.