CATL’s TENER Stack: 9 MWh Containerized Stacked BESS System

During the recent Intersolar Europe 2025, a few well-known companies showcased their latest megawatt (MW) scale battery energy storage system (BESS) targeting Europe’s growing utility-scale PV + storage market.  

Contemporary Amperex Technology Co., Limited (CATL), a well-known China-based energy storage solution provider, displayed its brand new TENER Stack series ultra-large capacity containerized BESS system during the event. Caspar Spinnen, Senior Specialist – Public Relations, from the CATL, exhibited and offered a brief description of the new stacked storage system to the TaiyangNews team at its booth. 

Performance 

This system, designed as a 2-split containerized BESS solution, can be stacked to deliver a cumulative energy storage capacity of up to 9 MWh, according to Spinnen. A company statement on its official website highlights that the system is equipped with CATL’s high-energy-density cells featuring up to 5 years of zero degradation. Compared to traditional 20-foot containers, it achieves up to a 45% improvement in volume utilization and a 50% increase in projected energy density. With an overhead louver, this stacked BESS system has a height of 4.7 meters and a 2-meter head width. Enhancing the BESS system’s compatibility and system efficiency, it supports both centralized and string Power Conversion System (PCS), targeting Europe’s application scenario, utility-scale PV + storage projects. 

Transportation 

Thanks to its "two in one" design, each half-height unit is strictly controlled under 36 tonnes, in line with logistical challenges associated with global transport regulations. 

Safety 

Concerning potential fire risk emanating from the installed large-size containerized BESS system, CATL has leveraged its own LFP battery chemistry, facilitating inherent thermal stability, noted the company statement. Additionally, it incorporates upgraded gas sensors with high sensitivity for much quicker fire suppression activation, along with a triple-layer insulation design that boosts fire resistance to 2 hours. Enduring extreme weather events, this stacked BESS product is certified to withstand up to magnitude 9 earthquakes and Category 5 hurricanes. 

Engineered with an overhead thermal management system (TMS), this design can reduce thermal radiation, claimed Spinnen. Its operational noise level is below 65 dB, making it suitable for urban usage.  

This recently released product is set for mass production, with the company starting shipments in the next 3 months.