Fire safety test evaluates CLOU Aqua-C2.5 system performance in dense station layout

CLOU Electronics has reported that its Aqua-C2.5 utility-scale energy storage system completed the CSA TS-800 Large-Scale Fire Test (LSFT) in February 2025.

The test, conducted in California under CSA Group supervision, evaluated the system’s capacity to limit thermal runaway propagation under simulated fire conditions.

The company stated that the Aqua-C2.5 is the first large-scale energy storage system to feature an active ventilation fire protection design.

Test simulates extreme thermal and spacing conditions

According to CLOU Electronics, the Aqua-C2.5 was tested using a configuration that replicated real-world station layouts.

Four 20-foot containers were positioned in an A/B A/D array, placed closely side-by-side and back-to-back at a spacing of 140 mm.

The arrangement was fully loaded to replicate operational stress.

During the trial, temperatures inside the cabinet exceeded 1000°C and burned continuously for 48 hours.

CLOU Electronics said adjacent cabinets maintained internal temperatures below 40°C due to the system’s active ventilation and off-gassing features.

CSA Group outlines limitations of previous standards

The TS-800 protocol was released in 2024 by the CSA Group to evaluate large-scale fire behaviour in energy storage systems.

Marvin Peng, Battery & Energy Storage Certifier at CSA Group, said: “The existing standards (such as UL 9540A) are capable of testing for thermal runaway, but they do not adequately simulate fire propagation scenarios, especially in multi-module container systems where a single battery fire can potentially ignite adjacent units or even the entire system.

“The core goal of the TS-800 test is to address this gap.”

CLOU highlights design features and certifications

Eric Wang, System Director of CLOU ESS Division, said: “CLOU committees that every product delivered is trustworthy and has undergone rigorous testing.

“The Aqua-C2.5 5MWh utility scaled energy storage system is the world’s first large-scale energy storage system to adopt an active ventilation fire protection design.

“Through active cell sensing, it triggers an electric shutter explosion suppression solution in thermal runaway scenarios, effectively controlling the spread of thermal runaway at extreme short distances in 140mm.”

The Aqua-C2.5, launched in September 2024, has received certifications including CE, UL1973, UL9540A, UL9540, IEC62619, IEC63056, IEC62477-1, UN38.3, NFPA855 and NEC.

It has also passed the IEEE693 seismic test.

Sungrow and other manufacturers also complete TS-800 testing

Other manufacturers have also conducted the TS-800 fire safety tests for their energy storage systems.

In 2024, Sungrow reported that its liquid-cooled system endured four hours of combustion in an A/B array without fire spreading to surrounding equipment.

Sungrow cited the use of pressure-sensing venting, multi-layer fire resistance and dual-compartment design in its PowerTitan system.

The company stated that its next-generation PowerTitan 2.0 product passed the large-scale test.

Trina Storage and BYD also reported completing the TS-800 fire test in October 2024 and January 2025 respectively.

CLOU Electronics completes TS-800 fire safety test for Aqua-C2.5 energy storage system: Summary

CLOU Electronics reported in February 2025 that its Aqua-C2.5 system completed the CSA TS-800 fire test.

The test evaluated fire propagation and containment in high-density energy storage system layouts.

It was conducted under CSA Group supervision using a layout replicating real station conditions.

Temperatures inside the tested cabinet exceeded 1000°C and burned for 48 hours.

Adjacent cabinets remained below 40°C due to active ventilation and off-gassing.

CSA Group launched the TS-800 standard in 2024 to test fire behaviour in multi-module systems.

Marvin Peng of CSA Group said current standards do not fully address fire propagation scenarios.

CLOU stated the Aqua-C2.5 is the first to use active ventilation fire protection.

The system includes electric shutter suppression and thermal detection features.

It holds multiple safety and compliance certifications including UL9540A and IEEE693.

Other manufacturers, including Sungrow, Trina Storage and BYD, also completed TS-800 testing.

Sungrow reported successful tests using its PowerTitan system and next-generation models.