Lithium-ion battery energy storage technology has evolved over the last several years to safely store energy while minimizing risks. Battery energy storage systems use rechargeable lithium-ion batteries that have benefited from research and development investments from the electric vehicle and consumer electronic industries. Lithium-ion batteries are a widely adopted battery technology found in various consumer applications, including cell phones, laptops, and other household electronics.

The design and engineering of batteries are subject to numerous codes specifically adopted for stationary battery energy storage systems. These codes are constantly being updated to improve safety and keep up with changes in the battery energy storage industry. Modern lithium-ion battery energy storage systems are subject to robust testing and detailed safety standards from recognized authorities such as the National Fire Prevention Association (NFPA) and Underwriters Laboratory (UL).

Once operational, projects mitigate risk by employing redundant safety systems, monitoring and control, technology assisted fire suppression and detection, and regular inspection and maintenance. Exact safety features depend on the chosen manufacturer, but typically include:

• Exclusive use of top-tier equipment integrated by an experienced party;
• Continuous monitoring for temperature, voltage, current, and health;
• A robust control system with protection, control, monitoring, and reporting capabilities;
• 24/7 remote monitoring, diagnostics, and troubleshooting capabilities;
• An engineered thermal management system appropriately sized and designed based on project location, container geometry, and battery cycles;
• Prudent isolation, spacing, and setbacks guided;
• Ongoing first responder training during construction and operations to regularly educate local first responders about the technology and coordinate a response plan in the unlikely event of an emergency.

UL 1973 – Module-level standard for both Light Rail and Stationary energy storage. Includes propagation tests (IEC 62619) that demonstrate fires are isolated to a single cabinet.

• One centrally located cell is heated until thermal runaway (fire); must demonstrate that fire does not spread to neighboring cell

UL 9540 – System-level standard for energy storage and equipment.

• Burn testing at the rack level to ensure proper fire behavior
• Large scale burn tests of entire BESS enclosures

NFPA 855 (2019/2023) and IFC (2018/2021)

• Hazard Mitigation Analysis by certified fire protection engineer
• Emergency Site Safety Plan
• First responder training
• Deflagration management
• Minimum spacing and setbacks