The rapid expansion of battery technology into the energy sector raises serious concerns about the installation of Battery Energy Storage Systems (BESS) in communities. Read this article to explore the Warwick, NY lithium-ion battery fire incident and gain insights into battery risk management solutions.

How the Incident Began

On June 26, 2023, fire alarms were heard at 6:06 PM at two lithium-ion Battery Energy Storage Systems (BESS) facilities in Warwick, NY. A fire broke out in the battery storage facility located on Warwick Valley Central School District land. Two of the newly installed commercial battery storage units ignited and burned. The fire caused heavy smoke and burning plastics, prompting the evacuation of the district office, middle school, high school, and elementary school. No one was injured during the event.

The cause of the incident has not been determined yet, but according to Ken Boyce, a principal engineer at UL, thermal runaway in lithium-ion batteries can be triggered by external conditions such as temperature or internal failures. That evening the area experienced heavy rain, high winds, and power outages as well as cloud-to-ground lightning.

Response and Recovery

As a precaution, all Warwick, NY schools remained closed until July 3, 2023. Dozens of toxins were detected during the three-day fire, but New Jersey Orange County Hazmat determined they were within a safe limit (News 12 in Westchester, NY). Because of the release of toxic chemicals during the fire, air quality samples were collected from different surfaces, including schools, buses, transit, and facility offices, and forwarded to a laboratory for study. All of the samples had levels of toxic chemicals that were below detectable limits. The Warwick, NY facility is closed and Convergent has enlisted a third party to investigate the incident.

Industry Implications

In site approvals, there is an overarching presumption of safety if compliance is met. But battery energy storage technology changes rapidly, much faster than regulation. In this example, the BESS installation in Warwick, NY was approved on May 18, 2020, by O&R Utilities and the New York State Education Department (NYSED) based on the installation of six General Electric (GE) Reservoir Storage Units (RSU). An Emergency Response Plan was developed by Convergent for Warwick, NY in 2020 based on that technology. The emergency response plan details compliance with various codes and standards as well as layers of protection to mitigate thermal runaway cascade and venting. The plan includes, for example, the requirement of a ventilation system to prevent flammable gas build-up and cell isolation to prevent thermal runaway cascade.

Facility rendering from the Emergency Response Plan developed by Convergent.

Three years later the facility came online with Powin’s newest model battery storage system referred to as the Centipede. The Centipede systems, two of which ignited and burned, were unique to Warwick, NY, and have not been deployed elsewhere.

Convergent non-Centipede battery storage solutions, on the other hand, have not shown similar safety issues. It is unknown if the facility’s Emergency Response Plan was later updated to reflect the change. A management of change (MOC) strategy could put in place workflows to update the emergency response plans, evaluate the differences between systems, and determine the new layers of protection and mitigation required. Convergent noted in the 2020 Emergency Response Plan that their LI-ion batteries were sourced, “…from Tier-1 suppliers with products that have a track record of utilizing technology and components that render the likelihood of a safety event low.”

Hazards of BESS Systems

The current regulatory framework is insufficient alone for predicting the most likely reasons for battery failure. A thorough battery hazard analysis, emergency response plan, and layers of protection, along with an effective MOC methodology, are required to maintain the safety of these energy storage units.

Fire Hazards

Lithium-ion or Li-ion batteries can overheat and catch fire or explode if not properly managed. The progression of a runaway reaction is difficult to predict given the many possible interactions. Safety issues for Li-ion batteries can be generalized to the following:

• Thermally unstable cathode
• Flammable electrolyte
• Overcharge-sensitive to cathode/anode
• Dendrite formation and defects in the separator

The various chemistries each provide a unique set of risks because of the unstable nature of high energy densities and small production differences between cells. Negative electrode chemistry is very important to understand, as some compounds are more unstable than others.

During thermal runaway, the release of flammable gases and the decomposition reactions occurring release high amounts of energy and can be up to 79% of the cell's total energy. The release of this much energy and the cell reaching temperatures of 400 to 900 ℃, depending on the battery type and state of charge, could result in the individual cells, modules, and then packs, beginning to catch fire. A single cell is hazardous; in a module or rack of cells, the thermal runaways can propagate between cells resulting in venting hazardous substances, fire, and when confined, explosions of a larger magnitude.

Chemical Exposure

During a Li-ion battery fire, the air in the immediate vicinity of the facility should be regarded as potentially corrosive, poisonous, and/or combustible due to the makeup of gases emitted, potentially exposing personnel and emergency responders to a health hazard. In thermal runaway, gases are released and are either burned, creating a flame jet or fire.

Alternatively, the gases and solid ejecta can accumulate, resulting in a gas or dust explosion. When the housing where the cells are encased is exposed to intense heat, the venting material can escape via that route. When oxygen is released from the decomposition reaction of the electrodes, electrolyte combustion reactions occur, resulting in flammable gases. These can include Oxygen (O2), Hydrogen (H2), Carbon Monoxide (CO), Carbon dioxide (CO2), Methane (CH4), Ethyne (C2H2), Ethylene (C2H4), and Ethane (C2H6). Ventilation in combination with fire suppression systems can be used to prevent the accumulation of flammable gases which could lead to deflagration. Deflagration vents (Blast panels) can be sized and adequately placed as a last layer of protection to minimize explosion damage to the system.

Fire Suppression

The 2019 battery fire and explosion at the Arizona Public Service (APS) facility in Surprise, AZ, was also a thermal runaway event. According to DNV GL, heat must be removed (by cooling with water) or the fuel must be dispersed in a unit to stop a thermal runaway event. According to the incident reports by DNV GL and the Firefighter Safety Research Institute, the fire suppression system for the LG Chem units at the APS facility was incapable of stopping thermal runaway.

The Staten Island Advance of Staten Island, N.Y. reported the fires in Warwick, NY burned for days. The 2020 Emergency Response Plan instructs that cabinet doors should not be opened by any emergency response personnel, including the Warwick Fire Department. The assumption is that the fire suppression system within the battery units would stop a thermal runaway event. Based on previous incidents, relying on the suppression system alone is not recommended. Various cooling methods should be investigated and secondary thermal runaway needs to be considered when responding to a battery fire.

A battery hazards analysis would include safety lessons learned from prior BESS incidents and necessitate testing of the fire suppression system within the battery units. Recommendations for adding commercially available fire suppression measures would be included for a safer facility.

Siting Hazards

Emergency management officials told News 12 Westchester that one of the battery storage facilities is located in close proximity to a 1,000-gallon propane tank and fuel pumps for the district bus garage. This incident shows that a facility siting study was not completed, otherwise, a priority list of problems would have been developed along with a mitigation strategy during the planning stages of facility installation. OSHA's PSM Rule (29 CFR 1910.119, Section (e)) includes facility siting as a part of the requirements of a Process Hazard Analysis (PHA) study for chemical facilities.

A facility siting is an important aspect of process safety for identifying affected personnel and buildings whenever there is the potential for hazards. Although it is primarily utilized for chemical facilities, facility sitings for energy storage systems should be performed since they pose both electrical and chemical threats to the site and the local communities.

We Can Help

Process safety aims to identify best practices, address potential risks, and ensure facilities are safe. A proactive approach using facility sitings, battery hazard analysis, and layers of protection studies, coupled with properly implemented management of change programs, can help minimize loss of life, environmental impact, equipment damage, and litigation. Call us today at 1.844.ioMosaic or fill out our online form. We would love to hear from you.