Water based suppression system leak causes battery shorting at Moss Landing Phase II
Feb 2022Published 10 Sept 2026Responsible editor: Chief Editor
- Where
- Moss Landing Phase II building, Moss Landing, California
- Operator
- Vistra Energy
- What
- Water leak from suppression system shorted batteries and caused smoke
- Injuries
- None reported
- Cause
- Leaking water hoses in water-based suppression system
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Companies named in the reporting of this entry (being named is not a finding of fault): Vistra Energy
What happened
On 13 February 2022, an early detection safety system activated at the 100 MW Phase II building of the Moss Landing Energy Storage Facility in Moss Landing, California, operated by Vistra Energy. An investigation found that the water-based suppression system released water that contacted batteries, and there was early evidence that water hoses leaked, causing some batteries to short and create smoke inside the building. Firefighters who attended found around ten melted battery racks.
The building's systems contained the event without requiring outside firefighting assistance, although off-site emergency responders were contacted as a precaution. No injuries to personnel were reported. The Phase II system was taken offline following the incident, and restart of the adjacent Phase I facility, which was unaffected, was paused while the operator assessed the Phase II event and incorporated any lessons learned.
Contributing factors
Early evidence pointed to leaking water hoses in the water-based suppression system, which allowed water to contact batteries and cause shorting, similar to a prior incident at the adjacent Phase I facility in September 2021.
Lessons learned
- Water hoses in battery storage suppression systems must be inspected regularly for leaks that could contact energised racks and cause shorting.
- Melted battery racks found after a water leak show that suppression system design must prevent water reaching live cells.
- A repeat water leak event at an adjacent phase requires review of shared suppression system specification and maintenance across the whole site.
More lessons on fire suppression and firefighting, from every incident on the register.
Not yet known
- Battery rack model and age
- Confirmed root cause of hose leaks
- Duration of Phase II outage
- Cost of repairs and lost revenue
This entry is updated when these are reported. Get an alert for the next one like it.
Source
Site page: Elkhorn Battery Energy Storage System (status, dates and other incidents)
Other entries that name Moss Landing
- New fire smoulders at Vistra Moss Landing battery site during cleanup
- Major fire at Moss Landing Energy Storage Facility, California, multi-day incident
- Clamp failure and coolant leak found during Moss Landing battery restart testing
- Battery storage fire reignites at Vistra's Moss Landing facility
- Megapack fire at PG&E Elkhorn Battery, Moss Landing, California
Published 2026-09-10. Written from public reporting. Descriptive, not investigative. See the data accuracy disclaimer.
