Battery unit fire during commissioning at Bouldercombe Battery Project, Rockhampton

What happened

In September 2023, during the final stages of commissioning at the Bouldercombe Battery Project near Rockhampton, Queensland, Australia, operated by Genex Power, one of 40 containerised battery units caught fire in the early evening, near the end of a discharge cycle. Site personnel disconnected the facility from the grid. The fire was contained to the single affected unit and did not spread to others, although the immediately adjacent unit was reported to have suffered minor thermal damage to electrical insulation.

Local fire and emergency services attended and, consistent with the guidance for this unit type, no water was applied directly to the burning cells. Nearby residents were advised to keep windows and doors closed during the response. There were no injuries. The damaged unit was later transported to a testing facility for detailed physical inspection. The commissioning programme was delayed by approximately six weeks while two replacement units were sourced and installed.

Contributing factors

As publicly disclosed by Genex Power around six weeks after the event, a preliminary root cause analysis by Tesla, the battery manufacturer, working with Genex Power and other stakeholders, found that the fault began on the AC side of the affected unit, at the power electronics interface with the AC bus bar inside that unit, and then propagated to the battery modules, leading to the fire. Genex Power stated that the failure was isolated to the power electronics interface in the individual unit and was not considered characteristic of the wider installation. Stated mitigation actions were: replacement of two identified power electronics units, physical inspection of the power electronics in the remaining units at the site, replacement of the two damaged battery units, and an upgrade by Genex Power of breaker control setting response times.

Lessons learned

1. Treat AC side power electronics, including inverter and bus bar connections, as a primary ignition source in battery unit safety cases.
2. Confirm that local fire services will apply the agreed suppression approach for the unit type before energisation.
3. Inspect power electronics in all units on site when a unit level fault is found, even if characterised as isolated.

More lessons on electrical protection and isolation, fire suppression and firefighting, from every incident on the register.

Not yet known

• Model and age of the affected battery unit
• Full root cause analysis findings
• Cost of the damage and delay

This entry is updated when these are reported. Get an alert for the next one like it.

Source

Energy-Storage.news (energy-storage.news)