Battery storage failure at SK Ulsan CLX site, Ulsan, South Korea
EIR-0664Provisional entry. This entry reflects a documented battery storage failure in Ulsan, South Korea, confirmed only by the EPRI failure database; the specific site and company involved have not been confirmed by any direct incident report and should not be treated as established. No further update is scheduled; the entry stays provisional until new information is published.
On 12 January 2022, a 10 MW, 50 MWh battery energy storage system in Nam-gu, Ulsan, South Korea, using NMC cell chemistry and installed indoors for peak load reduction, experienced a failure event approximately two years after entering service. According to the EPRI BESS Failure Incident Database, the event damaged about 1 percent of the installed capacity. No cause, fire response, injury or evacuation information has been reported. Based on matching location and capacity, the site is inferred to be SK Ulsan CLX, operated, owned and with equipment manufactured by SK On, though this identification has not been directly confirmed by any incident report. A 2018 news report describes a similarly sized 50MWh ESS installed at the SK Ulsan CLX complex by SK Innovation and SK E&S, but that article does not describe this incident.
Not reported in available sources.
- Even mature battery storage systems can experience localised failures affecting only a small fraction of installed capacity.
- Structured failure databases such as EPRI's are valuable for tracking incident frequency and severity even where narrative detail is limited.
- Matching technical specifications to public announcements is not a reliable method for confirming the identity of an incident site and should not be treated as established fact.
EPRI
Published 2026-09-11. Written from public reporting. Descriptive, not investigative. See the data accuracy disclaimer.