Vistra’s Moss Landing Storage Facility Offline Post “Overheating Incident”

Texas-based energy company Vistra Corp has begun its preliminary assessment of Phase I (300 megawatts) of its Moss Landing Energy Storage Facility in California following an “overheating incident” that occurred on the evening of Sept. 4 and rendered Phase I of the facility out of service.

Teams from Vistra, battery manufacturer LG Energy Solution, engineering and construction firm Fluence, and other external experts are conducting their initial walkthroughs of the building in order to gather information and begin their investigation into the root cause of the issue. The North County Fire Protection District of Monterey County is assisting with the investigation.

The teams are in the early stages of this investigation and expect that it will take some time to fully assess the extent of the damage before developing a plan to safely repair and return the battery system to operation. “We are working with our partners to ensure all necessary safety precautions are in place to minimize any risk during this process,” said Vistara.

Phase I / 300 MW is out of service and Phase II / 100 MW, which is located in a separate stand-alone building, is operational, explained the company.

Late Saturday evening, Sept. 4, the Moss Landing Energy Storage Facility, the largest battery storage facility of its kind in the world, experienced an overheating issue with a limited number of battery modules in its Phase I 300-megawatt/1200-megawatt hour system. There are multiple layers of safety integrated into the battery facility and the risk mitigation and safety systems worked as designed, detecting these modules were operating at a temperature above operational standards and triggering targeted sprinkler systems aimed at the affected modules.

As a result, the overheating was controlled and contained without the need for outside assistance, said Vistara. However, the Moss Landing team did ask the local fire department to respond to the site. Importantly, no injuries were reported to the facilities’ workers or the local community as a result of the incident.

The company states that it is prioritising safety and taking a conservative approach by keeping the entire facility offline as it investigates the root cause of the incident in partnership with its engineering contractor, Fluence, and battery manufacturer, LG Energy Solution. Vistra is uncertain about the timing of the return of the facility, pending an investigation and any needed repairs.