Explosion Risk from Lithium-Ion Batteries in Buildings
The increasing use of battery energy storage systems (BESS) creates a need for improved knowledge of the explosion risks associated with lithium-ion batteries in buildings. The aim of this study has been to identify the factors influencing the explosion risk and to evaluate how different technical measures, particularly ventilation and containment, can reduce this risk. The study has also assessed how explosion risk can be analysed using numerical simulations, and whether such tools can be used to support design and risk assessment in practice.
The study shows that thermal runaway can lead to the rapid release of large amounts of flammable gases. If these gases are not ignited immediately, they may accumulate and form explosive gas clouds. A deflagration can produce harmful overpressures, even with relatively small amounts of gas. This can happen due to delayed ignition or re-ignition after a fire has been extinguished.
Numerical simulations have been used to analyse how gas clouds form in battery rooms and how different measures affect the risk. The study shows that simulations are a useful supporting tool for design and risk assessment, but that they must be combined with experimental data and expert judgment.
The results show that there is no single universal solution to eliminate the explosion risk. Two main strategies have been identified: Extraction, where gases are removed through ventilation, and Containment, where the oxygen concentration is reduced. Both strategies can reduce the risk, but they have clear limitations, and flammable gas mixtures may still occur even under optimal conditions.
The report concludes that preventive measures must therefore be supplemented by consequence-mitigating measures, particularly explosion pressure relief, in order to limit damage to buildings and ensure personnel safety. Battery rooms should, as far as possible, be located outside buildings. If this is not feasible, they should be designed to allow direct venting to the open air and effective pressure relief in the event of a deflagration.
The study was funded by the Norwegian Directorate for Civil Protection (DSB) and the Norwegian Building Authority (DiBK).
The full report, in Norwegian with English summary, can be found here: https://assets.mustasj.dev/risefire/filer/Rapport-Eksplosjonsrisiko-fra-Litium-ion-Batterier-i-Bygninger.pdf