Fluence Validates Safety of Gridstack Pro 5000 in Benchmark-Setting Fire Safety Tests

Large-scale testing by Fluence and CSA Group shows Gridstack Pro 5000 system, delivering up to 5.6 MWh in a 20-foot enclosure, surpassing current and emerging safety standards

ARLINGTON, Va., June 12, 2025 (GLOBE NEWSWIRE) -- Fluence Energy, Inc. ("Fluence") (NASDAQ: FLNC), a global market leader delivering intelligent energy storage, services, and asset optimization software, today announced the successful completion of one of the largest fire safety evaluations in the energy storage industry. In partnership with CSA Group, a leading product testing, inspection, and certification organization, Fluence rigorously tested its high-density Gridstack Pro 5000 Series system. The results of these tests demonstrate that the system not only meets but exceeds current and emerging safety standards.  

Prior to the fire tests, Fluence conducted five days of explosion testing—two days of dispersion testing followed by three days of deflagration testing—continuing to lead the industry as one of the first companies to perform such a comprehensive explosion risk assessment. During dispersion testing, the system’s active ventilation effectively exhausted gases as designed, in compliance with NFPA 69, demonstrating its ability to prevent flammable gas accumulation. During deflagration testing, all six deflagration panels deployed as intended, in accordance with NFPA 68, validating the effectiveness of Gridstack Pro 5000’s passive safety features under extreme conditions.  

Gridstack Pro 5000 is designed to deliver up to 5.6 MWh of energy within a 20-foot enclosure, making it one of the highest density solutions on the market today to undergo this level of testing. To validate its safety at this scale, the system underwent rigorous testing using fully charged batteries. The large-scale fire tests were conducted at Safe Laboratories in North Carolina under the observation of CSA Group. These tests far exceeded the requirements of the current UL 9540A standard and aligned with emerging safety standards, including the forthcoming NFPA 855 (2026).  

Four enclosures containing live batteries were set up using minimum spacings, with the deflagration panels on the center enclosure opened. A fire was deliberately ignited in the center enclosure and allowed to fully develop without the use of fire suppression or firefighting intervention. The results confirmed that Gridstack Pro 5000 enclosures are designed to prevent propagation of battery fires under the conditions tested, even in tightly spaced layouts. No enclosure-to-enclosure propagation occurred, and surrounding battery cells remained within safe limits.