Explosion follows smoke event at solar-paired battery storage system in East Asia

In 2022, a thermal event occurred in a battery energy storage system installed alongside a solar generation facility in East Asia. The fire service was called after a report of smoke and entered the structure housing the battery system. Firefighters observed a large amount of smoke but no visible flames at that time. After they exited the structure, an explosion occurred approximately ten minutes later. No injuries were reported. The system used nickel manganese cobalt (NMC) cells, was around three years old at the time of the incident and was of an outdoor architecture. Reported damage affected a small proportion of the installed capacity.

Not reported in the available source material.

1. Thermal events in enclosed battery structures can produce heavy smoke with no visible flame, so the absence of flame should not be taken as an indication that the failure has stopped.
2. Explosions can occur some minutes after smoke or fire appears to have subsided, so standoff distances and exclusion zones should be held well beyond the point of initial suppression or inspection.
3. Responders attending battery storage incidents should be briefed on flammable off-gas accumulation and delayed explosion risk before entering or re-entering an affected structure.
4. Site emergency plans should identify who is authorised to declare a structure safe to enter and on what basis, including gas monitoring and remote temperature indications where these are available.

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