Tesla Energy has unveiled two major additions to its energy storage lineup, Megapack 3 and Megablock, marking a significant step in its mission to accelerate the world’s transition to sustainable power.
Megablock: Integrated Power, Faster Deployment
The headline product is the Megablock, a pre-assembled medium-voltage platform that integrates four Megapack 3 units with transformers and switchgear into one turnkey system. Designed for simplicity and speed, the Megablock delivers 20 MWh of AC storage capacity, supports more than 10,000 cycles across a 25-year lifespan, and reaches a site-level density of 248 MWh per acre.
Tesla says the design slashes construction costs by up to 40% and reduces installation time by 23%, with most of the assembly handled in the factory rather than on-site. VP of Energy and Charging Mike Snyder claimed Tesla can now deploy 1 GWh of storage in just 20 business days—enough to power hundreds of thousands of homes during peak demand.
Megapack 3: More Power, Fewer Connections
Alongside the Megablock, Tesla introduced the Megapack 3, its latest large-scale stationary battery. Each unit offers 5 MWh of capacity, up from 3.9 MWh in the Megapack 2, thanks to the use of new 2.8-liter LFP battery cells.
The Megapack 3 features a 78% reduction in electrical connections, a streamlined thermal system for improved cooling, and enhanced fire protection. Each unit is engineered for durability, capable of operating in extreme conditions from -40°C (-40°F) to 60°C (140°F).
Here's everything you need to know about @Tesla's newly announced Megablock, the latest in the company's industrial storage product lineup, which includes the new Megapack version 3:
— Sawyer Merritt (@SawyerMerritt) September 9, 2025
Megablock:
• 23% faster to install with up to 40% lower construction costs
• Plug and play… pic.twitter.com/AZMhzdTNlu
Scaling Up in Houston
Tesla plans to begin Megapack 3 production at a new Houston-area Megafactory in late 2026. The facility will have an annual manufacturing capacity of 50 GWh, equivalent to about 10,000 Megapack 3 units per year. Tesla has also lined up supply from its Nevada LFP cell plant (slated for 2025) and partnerships across Asia and the U.S.
Beyond Cars: A Growing Energy Business
While Tesla’s EV deliveries have recently slowed, its energy storage business is gaining momentum. In Q2, Tesla reported a record $846 million in gross profit from its energy division. By combining hardware like Megapack and Megablock with its Autobidder software for energy optimization, Tesla is positioning itself as a leader in grid-scale solutions for utilities, renewable energy producers, and even AI data centers.
With Megapack 3 and Megablock, Tesla is reinforcing that the future of the company is not just about cars—it’s about building the backbone of a clean, resilient global energy grid.