CATL Launches 9MWh Ultra-Large Capacity TENER Stack ESS

Chinese battery maker CATL on Thursday unveiled the TENER Stack, a 9MWh large-capacity energy storage system, set to enter mass production in 2025. The new solution, launched at the ees Europe exhibition, is designed to boost efficiency, safety and transportability in response to growing global electricity demand.

Targeted at utilities, industrial users and developers, the TENER Stack offers a 45 percent improvement in volume utilization and a 50 percent increase in projected energy density compared to conventional 20-foot container systems. According to CATL, the unit can charge up to 150 electric vehicles or supply electricity to a typical German household for six years.

The system incorporates CATL’s proprietary high-energy-density cells with five-year zero degradation technology.

Enhanced Compatibility and Efficiency

The TENER Stack supports both centralized and string PCS (power conversion system) architectures, allowing greater compatibility with AC-side equipment and grid systems. CATL said the system improves land-use efficiency by 40 percent and reduces overall construction costs by up to 20 percent, thanks to its compact design.

For example, deploying 800MWh of storage would require one-third fewer containers compared to 6MWh systems, the company said.

Adapted for Global Transport

To address logistical constraints in markets where transport weight limits are below 36 tonnes, CATL introduced a “two-in-one” split design. Each unit remains within legal weight limits for shipping in 99 percent of global markets, allowing standard handling and reducing transport-related costs by up to 35 percent.

The lower center of gravity and modular structure also enable deployment in areas with height restrictions, such as under bridges or in rural regions.

Safety and Durability Upgrades

CATL said the TENER Stack meets IEEE693 seismic standards, withstanding magnitude 9 earthquakes and Category 5 hurricanes. The system uses lithium iron phosphate (LFP) chemistry, which is less prone to thermal runaway, and features triple-layer insulation for up to two hours of fire resistance.

Upgraded gas sensors improve fire detection response by 35 percent, and the system’s overhead thermal management reduces operational noise to 65dB(A), making it suitable for urban settings.

Building on Previous Models

The TENER Stack follows CATL’s earlier TENER and TENER FLEX systems, which were deployed in over 1,700 global projects by late 2024. The new model aims to combine previous features with higher capacity and improved transport adaptability.

“CATL has always been at the forefront of the energy transition,” said Amanda Xu, CTO and President of ESS Europe at CATL. “With the TENER Stack, we offer a high-density, flexible solution for the next generation of energy storage.”

Hank Zhao, CTO of ESS Europe, added: “Nine megawatt-hours is not the limit. Each gain in energy density opens new potential for compact, high-capacity storage worldwide.”