Battery Energy Storage Systems (BESS) are at risk of thermal runaway caused by battery faults or external factors, potentially leading to fires or explosions. This article outlines the key safety measures for thermal runaway protection, including explosion venting design and fire-rated wall construction, to ensure system safety.

1. Explosion Venting Design

The purpose of explosion venting is to quickly release high-temperature and high-pressure gases during thermal runaway, preventing container rupture and subsequent explosions.

1.1 Explosion Assessment and Vent Area Calculation

• Assessment Requirements:
  Based on NFPA 855, determine if the system requires explosion venting by evaluating whether the combustible gas concentration (calculated using battery gas generation and container volume) exceeds the lower flammability limit (LFL).
• Vent Area Calculation:
  If venting is necessary, use NFPA 68 to calculate the required vent area and determine the placement of venting devices.

1.2 Explosion Venting Devices

• Vent Pro S Explosion Panels
  Designed specifically for BESS thermal runaway protection, these panels comply with international standards such as UL 9540A, NFPA 68, NFPA 855, and ATEX.
  • Key Features:
    • High safety compliance with international standards.
    • Easy installation and maintenance.
    • Customizable insulation thickness.
    • Suitable for a wide temperature range.

2. Fire-Rated and Explosion-Proof Wall Design

Fire-rated walls provide fire isolation within and around the BESS, preventing the spread of fire to adjacent areas.

2.1 Lightweight Fire-Rated Explosion-Proof Panels

• LS Lightweight Fire-Rated Explosion-Proof Panels
  These advanced materials are ideal for constructing fire-rated walls in BESS.
  • Advantages:
    • Exceptional fire performance, passing CNS Level 1 fire resistance and 3-hour interior wall tests.
    • Lightweight and compact, allowing faster construction and efficient space usage.
    • Flexible applications for walls and ceilings.
    • Cost-effective solution.

2.2 Fire Rating Requirements

• As per the Bureau of Standards, Metrology, and Inspection (BSMI) “Outdoor Battery Energy Storage System Site Verification Technical Specifications,” fire-rated walls must meet the required fire endurance standards certified by relevant authorities.

3. Relevant Standards and Regulations

The design of fire and explosion protection for BESS must comply with the following standards:

• CNS 10205: Emergency power battery systems for fire safety.
• CNS 62619: Safety requirements for secondary lithium batteries.
• NFPA 855:2020: Standard for installation of stationary energy storage systems.
• IEC 62933 series: Safety considerations and requirements for energy storage systems.

4. Risk Assessment

Comprehensive risk assessment is essential before design implementation, focusing on:

• Energy and gas composition released during thermal runaway.
• Venting, fire protection, and containment measures.
• Fire detection and automatic suppression systems.

Conclusion

Managing the risks associated with thermal runaway is critical to ensuring the safe operation of Battery Energy Storage Systems. Effective explosion venting and fire-rated wall designs significantly mitigate the risks, ensuring the reliability and safety of BESS.