4 October 2021 Battery Energy Storage Systems Explosion Hazards moles, or volume at standard conditions such as standard ambient temperature and pressure (SATP), which is gas at 1 bar of pressure and 25°C (77°F).
The thermal runaway gas explosion hazard in BESS was systematically studied. To further grasp the failure process and explosion hazard of battery thermal runaway gas, numerical modeling and investigation were carried out based on a severe battery fire and explosion accident in a lithium-ion battery energy storage system (LIBESS) in China.
It is notable that all examples plotted in Figure 5 lie well above the partial volume deflagration band, indicating that energy densities in commercial energy storage systems are sufficiently high to gener- ate explosions in the event of thermal runaway failure.
Conclusions Several large-scale lithium-ion energy storage battery fire incidents have involved explosions. The large explosion incidents, in which battery system enclosures are damaged, are due to the deflagration of accumulated flammable gases generated during cell thermal runaways within one or more modules.
Note that the Stationary Energy Storage Failure Incidents table tracks both utility-scale and C&I system failures. It is instructive to compare the number of failure incidents over time against the deployment of BESS. The graph to the right looks at the failure rate per cumulative deployed capacity, up to 12/31/2023.
6 October 2021 Battery Energy Storage Systems Explosion Hazards McMicken BESS in Surprise, Arizona The final example is the McMicken BESS incident in Surprise, Ari- zona. In this incident, a single battery rack went into thermal run- away, filling the container with flammable gas.