Tesla’s new Megablock system can power 400,000 homes in under a month

Tesla has unveiled the Megablock and Megapack 3, the latest additions to its industrial-scale battery storage solution lineup.

The products highlight Tesla Energy’s growing role in the company, as well as the division’s growing efforts to provide sustainable energy solutions for industrial-scale applications.

Megablock targets speed and scale

During the “Las Megas” event in Las Vegas, Tesla launched Megablock, a pre-engineered medium-voltage block designed to integrate Megapack 3 units in a plug-and-play system. Capable of 20 MWh AC with a 25-year life cycle and more than 10,000 cycles, the Megablock could achieve 91% round-trip efficiency at medium voltage, inclusive of auxiliary loads.

Tesla emphasized that Megablock can be installed 23% faster with up to 40% lower construction costs. The platform eliminates above-ground cabling through a new flexible busbar assembly and delivers site-level density of 248 MWh per acre. With Megablock, Tesla is also aiming to commission 1 GWh in just 20 business days, or enough to power 400,000 homes in less than a month.

“With Megablock, we are targeting to commission 1 GWh in 20 business days, which is the equivalent of bringing power to 400,000 homes in less than a month. It’s crazy. How are we planning to do that? Like most things at Tesla, we are ruthlessly attacking every opportunity to save our customers time, simplify the process, remove steps, (and) automate as much as we can,” the company said.

Megapack upgrades https://t.co/YLaN0hMpXO

— Elon Musk (@elonmusk) September 9, 2025

Megapack is our utility-scale energy storage platform, a key part of our mission to achieve sustainable abundance via sustainable energy.@Tesla_Megapack stores energy when production is high & discharges/releases it when the grid needs it – balancing renewables & supporting a… https://t.co/CGXfALsUSG

— Tesla (@Tesla) September 9, 2025

Megapack 3 is all about simplicity

The Megapack 3 is Tesla’s next-generation utility battery, designed with a simplified architecture that cuts 78% of connections compared to the previous version. Its thermal bay is drastically simplified, and it uses a Model Y heat pump on steroids. The battery weighs about 86,000 pounds and holds 5 MWh of usable AC energy. Tesla engineers incorporated a larger battery module and a new 2.8-liter LFP cell co-developed with the company’s cell team.

The Megapack 3 is designed for serviceability, and it features easier front access and no roof penetrations. About 75% of Megapack 3’s total mass is battery cells, with individual modules weighing as much as a Cybertruck. It’s also tough, with an ambient operating temperature range from -40C to 60C. This should allow the Megapack 3 to operate optimally from the coldest to the hottest regions on the planet.

Production is set to begin at Tesla’s Houston Megafactory in late 2026, with planned capacity of 50 GWh per year. Additional supply will come from Tesla’s 7 GWh LFP facility in Nevada, which is expected to open in 2025, as well as with third-party partners.

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:

Megablock:
• 23% faster to install with up to 40% lower construction costs
• Plug and play… pic.twitter.com/AZMhzdTNlu

— Sawyer Merritt (@SawyerMerritt) September 9, 2025