Fluence Achieves Major Safety Milestone for Gridstack Pro 5000 with Comprehensive Fire Testing

Fluence Validates Safety of Gridstack Pro 5000 in Benchmark-Setting Fire Safety Tests
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Large-scale testing conducted by Fluence in collaboration with CSA Group has confirmed that the Gridstack Pro 5000 system, which delivers up to 5.6 MWh within a 20-foot enclosure, exceeds both current and emerging safety standards.

**ARLINGTON, Va., June 12, 2025 (GLOBE NEWSWIRE)** — Fluence Energy, Inc. (“Fluence”) (NASDAQ: FLNC), a global leader in intelligent energy storage, services, and asset optimization software, has successfully completed one of the most extensive fire safety evaluations in the energy storage industry. In partnership with CSA Group, a prominent organization in product testing, inspection, and certification, Fluence rigorously assessed its high-density Gridstack Pro 5000 Series system. The results indicate that the system not only meets but surpasses existing safety standards.

Before conducting fire tests, Fluence executed five days of explosion testing, comprising two days of dispersion testing and three days of deflagration testing. This positions Fluence as a frontrunner in the industry, being one of the first companies to undertake such a thorough explosion risk assessment. During the dispersion tests, the system’s active ventilation successfully exhausted gases as intended, adhering to NFPA 69 standards and demonstrating its ability to prevent the accumulation of flammable gases. In the deflagration tests, all six deflagration panels functioned as designed, in accordance with NFPA 68, confirming the efficacy of the Gridstack Pro 5000’s passive safety features under extreme conditions.

The Gridstack Pro 5000 is engineered to deliver an impressive 5.6 MWh of energy within a compact 20-foot enclosure, making it one of the highest density solutions in the market to undergo this level of rigorous testing. To ensure safety at this scale, the system was tested with fully charged batteries. Large-scale fire tests were conducted at Safe Laboratories in North Carolina, under the observation of CSA Group. These tests significantly exceeded the current UL 9540A standard and were aligned with upcoming safety standards, including the anticipated NFPA 855 (2026).

The testing involved setting up four enclosures containing live batteries with minimum spacing, while the deflagration panels on the center enclosure were opened. A fire was deliberately ignited in the center enclosure and allowed to develop fully without any fire suppression or intervention. The results confirmed that the Gridstack Pro 5000 enclosures are designed to prevent the propagation of battery fires under the tested conditions, even in densely spaced arrangements. No fire propagation occurred between enclosures, and surrounding battery cells remained within safe limits.

“We designed the Gridstack Pro 5000 to redefine the possibilities of energy storage density, and with that comes the responsibility to ensure it can be done safely,” stated Peter Williams, Fluence SVP and Chief Product and Supply Chain Officer. “This testing surpasses current industry requirements and serves as a real-world demonstration of how next-generation systems must perform under worst-case scenarios.”

To enhance transparency and technical rigor, Fluence invited independent observers, including experts from organizations such as Hiller and members of standards development committees, to witness the testing at Safe Labs.

“Fluence continues to demonstrate its commitment to fire safety by exceeding industry standards,” remarked Paul Hayes, Hiller VP of Energy Infrastructure and Fire Protection Engineer. “The scale and extent of their testing illustrate readiness to meet the upcoming 2026 NFPA 855 safety standard ahead of its publication. The Gridstack Pro 5000’s successful performance under various physical test scenarios confirms the system’s safety architecture and Fluence’s dedication to industry safety standards.”

Throughout the fire tests, Fluence collected detailed gas sampling data to support plume analysis, enhance emergency response training, and provide permitting guidance. This complements the company’s broader safety initiatives, including specialized training for first responders regarding battery energy storage systems.

Since 2022, Fluence has made significant advancements in safety testing protocols and certification processes across the energy storage industry through deflagration and large-scale fire testing. The company collaborates with leading laboratories to integrate advanced safety features into its systems, aiming to prevent, detect, and contain thermal events while maximizing energy capacity within increasingly compact designs.

### About Fluence

Fluence Energy, Inc. (Nasdaq: FLNC) is a global market leader in intelligent energy storage and optimization software for renewables and storage. The company’s solutions and operational services are instrumental in creating a more resilient grid and unlocking the full potential of renewable energy portfolios. With gigawatts of projects successfully contracted, deployed, and managed across nearly 50 markets, Fluence is transforming how we power our world for a sustainable future.

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