Investigating Lithium Ion Battery Energy Storage System Explosions: Enhancing Firefighter Safety
Abstract:
The report titled "Four Firefighters Injured In Lithium-Ion Battery Energy Storage System Explosion - Arizona" delves into a near-miss incident involving a deflagration at a lithium-ion battery energy storage system (ESS) facility in Surprise, Arizona. Funded by the U.S. Department of Homeland Security (DHS) and Federal Emergency Management Agency (FEMA), this report provides a comprehensive analysis of the incident, fire service response, and recommendations to bolster codes, standards, and emergency response training, aiming to safeguard first responders, maintenance personnel, and nearby communities.
Introduction:
The rapid expansion of lithium-ion battery energy storage systems (ESS) presents novel challenges for the fire protection community, necessitating a deeper understanding of the associated risks and effective mitigation strategies. The recent incident in Surprise, Arizona underscores the urgent need to address the safety implications of these systems. By examining the incident through the lens of fire safety and firefighter safety, this report seeks to elucidate critical insights to inform future safety protocols and regulatory frameworks.
Understanding the Incident:
On April 19, 2019, a deflagration event occurred within a 2.16 MWh lithium-ion battery ESS, resulting in severe injuries to four career firefighters. The incident unfolded as the smoke detector within the ESS signaled an alarm condition, triggering the discharge of a total flooding clean agent suppressant (Novec 1230). Subsequent assessments by the hazardous materials (HAZMAT) team revealed elevated levels of hydrogen cyanide (HCN) and carbon monoxide (CO) in the vicinity, indicating a potential thermal runaway event within the battery cells. Despite precautionary measures, including the establishment of a hot zone and continuous monitoring, a deflagration event occurred upon opening the ESS door, leading to serious injuries to all HAZMAT team members.
Technical Analysis:
The deflagration event in the lithium-ion battery ESS facility can be attributed to the thermal runaway phenomenon, characterized by uncontrolled exothermic reactions within the battery cells. Lithium-ion batteries are susceptible to thermal runaway due to factors such as internal short circuits, overcharging, and physical damage. Once initiated, thermal runaway can propagate rapidly, releasing significant amounts of heat, flammable gases, and toxic byproducts, posing grave risks to personnel and property.
The rate of thermal energy release during a lithium-ion battery thermal runaway can be described by the following equation:
q= Q / Δt
Where:
q = Rate of thermal energy release (W)
Q = Total thermal energy released (J)
Δt = Time duration of the event (s)
Recommendations for Firefighter Safety:
Drawing from the insights gleaned from the incident, the report offers a set of recommendations aimed at enhancing firefighter safety in similar scenarios. These recommendations encompass the implementation of stringent standards and codes for ESS sites, comprehensive HAZMAT training programs emphasizing ESS safety protocols, deployment of advanced gas monitoring systems capable of remotely assessing air quality and identifying hazardous substances, and measures for explosion prevention and protection, including the use of explosion-resistant enclosures and fire suppression systems specifically designed for lithium-ion battery installations. Additionally, the report advocates for continuous research initiatives and full-scale testing to inform effective fire service response tactics and ensure the development of robust safety measures tailored to the evolving landscape of energy storage technologies.
Implications for Codes and Standards:
The incident in Surprise, Arizona underscores the critical need to revise and enhance existing codes and standards governing lithium-ion battery ESS installations. While the ESS involved in the incident complied with relevant codes at the time of its commissioning, the report highlights the necessity of ongoing revisions to align with evolving industry best practices and technological advancements. Recommendations put forth in the report aim to inform the development of comprehensive guidelines that prioritize firefighter safety without compromising operational efficiency or hindering the adoption of clean energy technologies.
Conclusion:
The near-miss incident in Surprise, Arizona serves as a poignant reminder of the inherent risks associated with lithium-ion battery energy storage systems and the imperative to prioritize firefighter safety in the design, operation, and maintenance of such facilities. By leveraging technical analyses, firsthand accounts, and lessons learned from the incident, this report offers valuable insights into the complexities of ESS-related incidents and provides a roadmap for enhancing firefighter safety through proactive risk mitigation strategies, robust training programs, and stringent regulatory frameworks.
Hossam Shalabi, P.Eng., Ph.D.
CFEI Special Advisor; National Life Safety Group
National Life Safety Group is an industry leading consultancy firm, specializing in public and workplace safety, with a focus on best practices in the integration of facility fire & life safety, physical security and emergency management.