September 16, 2025
As the number of Li-ion Battery Energy Storage Systems (BESS) facilities being installed continues to rise rapidly, it’s crucial to address the hazards and risks associated with these facilities during the design, installation and operation phases. AEGIS published our initial white paper on this topic back in 2021. As more BESS facilities are constructed and remain operational for longer periods, we continue to learn from both losses and model practices across our membership. The first revision to the BESS white paper was released in 2023, expanding on the Deflagration Hazard Study (DHS), installation-level testing criteria, and concerns associated with various facility configurations, such as parking garage-style layouts and enclosure stacking. Available now, this second revision contains additional and updated information, including:
- Details on how Probable Maximum Loss (PML) and Maximum Foreseeable Loss (MFL) are determined by AEGIS based on BESS separation and arrangements
- Information that should be provided on displays/control consoles for emergency responders
- Considerations for site security and flood risk management for BESS installations
- A reference to recently developed CSA TS-800:24 for Large Scale Fire Testing (LSFT) Criteria
- Updates to references reflecting the latest version of NFPA 855
- A reference to IEEE P2686 – Recommended Practice for Battery Management Systems in Energy Storage Applications