CATL catapults itself into the record books after unveiling the TENER Stack, the world’s first 9-MWh ultra-large capacity energy storage system solution. The company revealed the next-gen product at ees Europe 2025.
“CATL has always been at the forefront of the energy transition,” said Amanda Xu, CTO ESS and president of ESS Europe CATL. “To meet the expectation of a BESS system that has high energy density, small footprint, simpler AC-side configuration and flexible deployment, we bring the latest CATL TENER energy storage solution. It breaks the limitations of power capacity and product transportation, and makes breakthroughs in space utilization, energy efficiency, and cost.”
TENER Stack incorporates CATL’s high-energy-density cells with five-year, zero-degradation technology, achieving a 45% improvement in volume utilization and a 50% increase in projected energy density compared to conventional 20-ft container systems. The internal capacity reaches up to 9 MWh.
To enhance compatibility and system efficiency, TENER Stack supports both centralized and string PCS (power conversion system) architectures. This dual technology path ensures seamless integration with mainstream AC-side equipment and a wider array of grid applications.
The stacked space efficiency of TENER Stack delivers significant economic value. For instance, deploying 800 MWh of storage using TENER Stack requires nearly one-third fewer containers than traditional 6-MWh systems. This reduces the number of PCS units and hidden costs associated with system oversizing, and increases land-use efficiency by 40%. Overall, developers can expect up to 20% optimization in total station construction costs.
In response to logistical challenges associated with transporting containers exceeding 36 tonnes, the legal threshold in many countries, CATL has developed the “two-in-one” design. Each half-height unit is strictly controlled under 36 tonnes, ensuring compliance with transport regulations across 99% of global markets. This split design allows for standard shipping methods, including standard container spreaders and liners, significantly reducing waiting times and specialized transport costs by up to 35%. With a lower center of gravity and flexibility for height restricted routes, TENER Stack can easily adapt to unique transport scenarios such as bridges and rural areas, highlighting the advantages of its innovative structural design.
With fire safety under global scrutiny, TENER Stack leverages CATL’s robust LFP battery chemistry. Upgraded gas sensors offer 40% higher sensitivity, triggering suppression systems 35% faster. A new triple layer insulation design boosts fire resistance to two hours and the system meets IEEE693 seismic standards, enduring magnitude 9 earthquakes and Category 5 hurricanes. Additionally, an overhead TMS (thermal management system) design reduces thermal radiation, cuts land and maintenance costs and keeps noise to 65dB(A) at 1 m, which is ideal for urban use.
“TENER Stack, giant, flexible, reliable and quiet. We are not only delivering an energy storage product, but a solution for energy accessibility that can be applied globally,” said Hank Zhao, CTO of ESS Europe CATL. “9 MWh is not the limit of the energy capacity or space. Every breakthrough in energy density in the future will unleash greater energy value from a smaller footprint.”
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