In August 2021, Texas-based Vistra Energy announced their Moss Landing Battery Energy Storage Facility, located in Monterey County, California, was the world’s largest Battery Energy Storage Facility, after adding a 100 MW (megawatt) facility (Phase II Building) to the site’s existing 300 MW facility (Phase I Building). What was once the site of the world’s largest battery energy storage facility is now the site of two inactive battery plants.
In September 2021, the 300MW facility was shutdown indefinitely, due to an incident that caused the battery storage plant’s fire suppression system to soak ~7,000 batteries. Vistra was planning to restart the 300MW facility but have canned those plans due to the most recent incident, which still remains under investigation
This recent event occurred on February 13th, just after the Los Angeles Rams won the Super Bowl, when local fire crews were called to the newer, Phase II Building – 100MW facility – for a similar incident. The Early Detection Safety System for the Phase II Building was activated and in accordance with their procedure and protocol, they contacted off-site emergency response. Vistra management noted that the Phase ii Building’s early detection safety system activated, contained the event, and that there are no injuries to personnel.
North County Fire District Chief Joel Mendoza says four trucks responded to the February 13 event, and when they arrived, there were no flames, but ten lithium-ion battery packs had been melted. The situation looked very similar to the September incident: wet batteries and melted plastic around the battery racks. The team stayed on site for about 24 hours, to ensure no subsequent fire would break out.
You may recall our article about a Lithium-ion Battery
Runaway Event in the September 2020 newsletter. Although, this was in no “runaway event”, Lithium-ion batteries build up a lot of heat and Vistra’s Early Detection Safety System responded appropriately to prevent such an event. But if these batteries reach a thermal runaway condition, they can produce fires that are difficult to contain because water does not put them out.
“An investigation is underway to determine what caused the safety system to activate. While this is in its very early stages, what we know is the water-based suppression system released water that contacted some batteries. There is early evidence that water hoses leaked and that some batteries shorted, creating smoke in the building, similar to what we observed with the September incident at our 300-MW Phase I facility next door,” said Vistra in a released company statement.
In the meantime, the facility remains offline to avoid any future fire incidents and it will remain dormant until Vistra Energy figures out what happened and can repair and correct any issues.