Tesla plans Megapack 3 and Megablock production at Houston, targeting 50 GWh/year

Tesla/Megapack 3 / Megablock

Tesla plans to build Megapack 3 and Megablock grid batteries at its Houston Megafactory, with a capacity target of 50 GWh a year. Its earlier guidance put the start of production in late 2026, and no source reviewed confirms that production has begun. Megapack 3 units are about 5 MWh each, and a Megablock packages four of them into one 20 MWh block.

• Tesla said it plans to start Megapack 3 production in Houston in late 2026 (Electrek, 8 Sep 2025).
• TechCrunch reported that both products would not enter production until the latter half of 2026 (9 Sep 2025).
• Target: 50 GWh of annual capacity.
• Megablock adds a transformer and switchgear to four units, for 20 MWh per package.
• As of 15 Oct 2026 the start of production is not confirmed in the sources checked.