PR Newswire - CLOU Aqua C2.5 Establishes Unprecedented Safety Benchmark with 59-Hour Large-Scale Fire Test

SHENZHEN, China, June 25, 2025 /PRNewswire/ -- CLOU Aqua C2.5 5MWh liquid-cooled energy storage system has successfully completed an extraordinary 59-hour and 10-minute Large-Scale Fire Test - setting a new benchmark for energy storage safety evaluation. The test was fully witnessed and documented by CSA Group personnel throughout the entire process. The system demonstrated exceptional resilience by maintaining complete structural integrity while withstanding temperatures exceeding 1,300°C, without resulting thermal runaway propagation between initiating BESS and target BESSs nearby.

The Large-Scale Fire Test is designed to evaluate the possibility of fire spreading from one system enclosure to adjacent systems in centralized installations of energy storage systems. During the test, under conditions where the triggered system was fully engulfed in flames, the fire did not cause any adjacent systems to exhibit valve opening or thermal runaway signs. This demonstrates the product's exceptional flame-retardant and thermal insulation performance, meeting the customized testing requirements of the client.

This testing milestone embodies Clou's profound commitment to addressing clients' safety imperatives. By ignition of Container A, sustained combustion persisted for 59 hours and 10 minutes until complete extinguishment without reignition. The testing methodology accurately simulates the full progression of extreme fire scenarios - from ignition, escalation to natural attenuation. The obtained critical data provides essential parameters for optimizing fire protection system design in energy storage plants.

"The test results have far exceeded our most stringent safety benchmarks. CLOU's integrated approach combining superior flame retardancy, advanced thermal management and inherent system protection represents a significant advancement in energy storage safety engineering." Eric Wang, System Director of CLOU ESS Division emphasized the solution's forward-looking design, specifically engineered to address emerging challenges posed by high-energy-density battery technologies.

The successful evaluation from this test conclusively demonstrates Aqua C2.5's readiness for GW-scale deployment. The system delivers unparalleled protection against prolonged thermal runaway events while establishing new certification benchmarks for the global energy storage industry. This milestone reinforces CLOU's leadership in next-generation energy storage safety technologies, carrying significant implications for utility-scale, commercial and industrial applications worldwide. The system's performance sets a new safety standard benchmark for the sector, demonstrating that extreme safety protocols and high operational efficiency can be seamlessly integrated into modern energy storage solutions.