Battery storage thermal runaway linked to overcharging at Pyeongchang wind-integration site

A battery energy storage system serving a wind integration application in Pyeongchang, South Korea, experienced a thermal runaway event on 24 September 2019. The system was an indoor installation using NMC lithium-ion cells from Samsung SDI, with a capacity of 21 megawatt-hours and about 2.7 years in service at the time. According to the EPRI BESS Failure Incident Database, energy management system log records confirmed that the battery had been subject to repeated overcharging and discharging, described as battery abuse. The database does not report the extent of any fire, the emergency response, injuries or downtime, and no other detailed public account of the event was available at the time of writing.

The database record states that energy management system logs confirmed repeated overcharging and discharging of the battery, described in the source as battery abuse. No further contributing factors are reported.

1. Battery and energy management systems should enforce and alarm on state-of-charge and charge rate limits so that repeated overcharge or overdischarge cannot persist unnoticed.
2. Operators should periodically audit energy management system logs for abusive charge and discharge patterns that accelerate cell degradation.
3. Storage serving variable duty such as wind integration may need an operating envelope tailored to that duty, with the envelope reviewed as the asset ages.

EPRI

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