A holistic approach to improving safety for battery energy storage systems

The integration of battery energy storage systems (BESS) throughout our energy chain poses concerns regarding safety, especially since batteries have high energy density and numerous BESS failure events have occurred. Wider spread adoption will only increase the prevalence of these failure events unless there is a step change in the management and design of BESS. To understand the causes of failure, the main challenges of BESS safety are summarised. BESS consequences and failure events are discussed, including specific focus on the chain of events causing thermal runaway, and a case study of a BESS explosion in Surprise Arizona is analysed. Based on the technology and past events, a paradigm shift is required to improve BESS safety. In this review, a holistic approach is proposed. This combines currently adopted approaches including battery cell testing, lumped cell mathematical modelling, and calorimetry, alongside additional measures taken to ensure BESS safety including the requirement for computational fluid dynamics and kinetic modelling, assessment of installation level testing of the full BESS system and not simply a single cell battery test, hazard and layers of protection analysis, gas chromatography, and composition testing. The holistic approach proposed in this study aims to address challenges of BESS safety and form the basis of a paradigm shift in the safety management and design of these systems.