Tesla Begins Megapack 3 Production in Texas
Tesla has started manufacturing its next-generation Megapack 3 battery storage system at a new Texas facility, aiming for 50GWh annual capacity.
Tesla has begun producing its Megapack 3 battery energy storage system (BESS) at a new facility in Brookshire, Texas. The company plans for the Texas site to reach an annual production capacity of 50 gigawatt-hours for the new product, with deliveries expected to start towards the end of 2026.
According to the report from Energy-Storage.News, Tesla currently operates over 77 gigawatt-hours of Megapack units globally with a claimed uptime of 99.3%. The company deployed 8.8GWh of storage in the first quarter of this year and 13.5GWh in the second quarter. While these quarterly figures include residential Powerwall units, the utility-scale Megapack accounts for most sales. Tesla also recently signed a multi-year agreement with NatPower to supply over 25GWh of BESS capacity in Italy and the UK.
The Megapack 3 is a lithium iron phosphate (LFP) battery system designed to deliver 5 megawatt-hours of energy capacity and 2.5 megawatts of power output. Tesla sells it in several configurations tailored for different applications. A standard version includes an integrated inverter, thermal management, and an AI control platform for automated energy trading.
Configurations and Applications
Other configurations include a Megapack with an electrolyser buffer for combining hydrogen production with grid services, a version optimised for carbon capture operations, and a mobile, trailer-mounted unit compatible with Tesla superchargers for electric vehicle fleets. A final hybrid configuration incorporates a 50-kilowatt fuel cell.
The system is designed for peak shaving, frequency regulation, capacity firming, and renewable energy integration. It can serve as a standalone utility system for grid stability, provide backup power for data centres and commercial businesses, and function within microgrid setups.
The Megablock Advantage
A major development is the Megablock, a pre-engineered configuration combining up to four Megapack 3 units. This provides 20MWh of capacity with four-hour discharge durations, allowing up to 248MWh to be installed on a single acre.
The Megablock design significantly reduces installation complexity. Individual Megapack installations can require up to 24 cable connections per unit to a medium-voltage transformer. By comparison, a Megablock needs only three busbar connections per pack. Tesla claims this cuts installation time by 23% and construction costs by 40%, enabling a gigawatt-hour of capacity to be deployed in just 20 days. The Megablock is designed for a 25-year lifespan.
Supply Chain and Incentive Challenges
One potential barrier is Tesla's current reliance on battery cells from China and Southeast Asia. U.S. Tariffs on BESS made with foreign components could affect affordability. Also, to qualify for U.S. Production and investment tax credits from 2026, at least 55% of a BESS unit's total cost must be manufactured domestically under Foreign Entity of Concern rules.
The report states Tesla hopes to avoid these issues through a partnership with LG Energy Solution for LFP cells produced at LG facilities in Michigan. Production lines at several U.S. Factories are being converted from making NMC pouch cells to LFP prismatic cells. However, the article notes Tesla must hope this manufacturing transition is not delayed as it seeks to decouple from Chinese supply chains.
Technical Comparison with Previous Model
The Megapack 3 offers a 28% increase in energy density over its predecessor, the Megapack 2 XL, storing 5MWh compared to 3.9MWh within the same 28-foot container footprint. This is achieved by using larger 2.8-litre battery cells, which also reduce thermal-system connection points by 78%.
Key performance metrics show differences between the models. Both have a 100% depth of discharge, but their round-trip efficiency varies. The Megapack 3 has a stated efficiency of 92.5%. The Megapack 2 XL's efficiency ranges from 91.7% to 93.7% depending on the specific configuration. While the older model was designed for 2- and 4-hour durations, the new one is designed for up to 8 hours.
| Metric | Megapack 2 XL | Megapack 3 |
|---|---|---|
| Energy Capacity | 3.9 MWh (CO10/CO11), 4.3 MWh (CO12) | 5 MWh |
| Power Output | ~1 MW (4-hr CO10/CO11), ~1.9 MW (2-hr CO10/CO11), ~1 MW (CO12) | 2.5 MW |
| Round-Trip Efficiency | 91.7% - 93.7% | 92.5% |
| Dimensions | 8.80m × 1.65m × 2.79m | 8.1m × 1.6m × 2.8m |
| Weight | 38,100 kg | 38,000 kg |
| Cycle Life | 3,000 - 5,000 cycles | At least 10,000 cycles |
Both the Megapack 3 and Megapack 2 XL exceed the standard U.S. 40-ton weight limit, requiring multi-axle trailers and often special permits for transport. The Megapack 3 has a cycle life of at least 10,000 cycles and comes with a warranty of up to 20 years, compared to the 3,000-5,000 cycle life of the Megapack 2 XL.
