Vistra’s very large utility-scale battery at the site of the former Pacific Gas & Electric Moss Landing power plant has been taken partly offline. The Moss Landing Energy Storage Facility “experienced an overheating issue with a limited number of battery modules in its Phase I 300-megawatt/1200 megawatt-hour system,” on the evening of Sept. 4, according to Vistra.
The storage plant was recently expanded and 100 MW of new storage, housed in a separate building, remains up and running.
Vistra, together with battery manufacturer LG Energy Solution, engineering firm Fluence, and others are investigating the cause of the overheating. “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,” Vistra said last week.
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The contribution of rising levels of battery storage connected to the grid is publicly visible in real time on the California Independent System Operator website. Today’s Outlook shows how much storage is on the system.
Currently, there is 1,500 MW of large lithium ion battery capacity, up from 500 MW a year ago. That total is expected to double by the end of this year. In early 2018, there was just 50 MW of battery capacity.
The additional storage has helped grid operators balance the system in the face of growing climate change impacts, including major wildfires and reduced hydropower from the drought in California and the West, according to CAISO.
“No other grid in the country is adding battery storage at the rate that California is,” Gabe Murtaugh, CAISO storage sector manager for market and infrastructure policy, stated Sept. 13. The increase in storage is pushing “grid operators to quickly learn grid management strategies and tools to best integrate the new technology.”
Battery storage assets usually charge during the day, when solar energy is abundant and prices are low, and discharge as the sun sets and solar resources fall offline but demand remains high.