Quantitative fire likelihood assessment of battery home storage systems in comparison to general house fires in Germany and other battery related fires

Battery storage systems are becoming an integral part of the energy transition by enabling energy availability during periods of low renewable energy generation and by providing various grid services. Currently, the most battery storage systems are deployed in home storage systems (HSSs) and electric vehicles (EVs), and their growth continues exponentially. However, despite this upside development, there are public concerns about potential fire risks associated with photovoltaic (PV) home storage systems and EVs. This paper presents a quantitative analysis comparing statistics of fires occurring in HSS with fires in PV systems, in EV, internal combustion engine (ICE) vehicles and, general house fires. However, because of a lack of available data, HSS fire incidents in Germany for 2023 were determined through web crawling, while other probabilities were derived from already existing research data. The results show a significantly lower probability of an HSS fire compared with a general house fire. In detail, the findings indicate that the probability of an HSS fire is very low (0.005 %) and is 50 times lower than for a general house fire. All home appliances have a generally low probability of catching fire, which is also true for HSS. If compared to other home appliances, HSS share roughly the same probability of catching fire as tumble dryers. Furthermore, compared with the fire probability of HSS, PV systems demonstrate an even lower probability, approximately three times lower than that of HSS. The probability of a traditional ICE vehicle fire (0.089 %) is approximately four times higher than that of an EV fire. The probability of an HSS catching fire is approximately 18 times lower than an ICE catching fire and four times lower vs. an EV. These findings provide important insights into the risks and safety aspects of battery storage in the residential buildings, thus supporting to make informed decisions about integrating of renewable energy systems. • HSS fires 50 times less likely than house fires, four times less likely than EV fires. • HSS fires as likely as tumble dryer fires, three times more likely than PV fires. • Indoor HSS fires highlight need for better risk mitigation. • Standardized reporting essential for reliable HSS fire data