US developer Vistra has grid connected a 300MW battery storage system located in Monterey County in California.
The 300MW/1200 megawatt-hour (MWh) Moss Landing energy storage facility located on-site at Vistra’s Moss Landing power plant is the largest of its kind in the world.
Construction is now underway on phase two, which will add an additional 100MW/400MWh to the facility by August 2021, bringing the battery plant’s total capacity to 400MW/1600MWh.
The energy storage system is housed inside the Moss Landing power plant’s completely refurbished former turbine building and spans the length of nearly three football fields.
Phase one is made up of more than 4500 stacked battery racks or cabinets, each containing 22 individual battery modules.
These capture excess electricity from the grid, largely during high solar-output hours, and can release the power when energy demand is at its highest and solar electricity is declining, usually early morning and late afternoon.
Phases one and two of the Vistra Moss Landing energy storage facility are backed up by long-term resource adequacy contracts with Pacific Gas and Electric Company (PG&E).
Vistra CEO Curt Morgan said: “This is a keystone project and it is important in so many ways – it revitalizes an existing power plant site and utilises active transmission lines, enhances grid stability, fills the reliability gap created by intermittent renewables, provides emission-free electricity, supports California’s sustainability goals and mandates, significantly benefits the local community, and ultimately provides affordable electricity to consumers.
“A battery system of this size and scale has never been built before. As our country transitions to a clean energy future, batteries will play a pivotal role and the Vistra Moss Landing project will serve as the model for utility-scale battery storage for years to come.”
Vistra said that ultimately the Moss Landing site provides a “unique opportunity for extensive future expansion” of the battery storage system, of up to 1500MW/6,000MWh of storage capacity.
California State Senator John Laird said, “As the largest of its kind in the world, the Vistra Zero Moss Landing Energy Storage Facility will store renewable energy, releasing it when it is needed most.
“It is meaningful, ambitious projects like these that will help to pave the way to a 100% clean energy future for California and the rest of the world.”
Vistra’s storage portfolio comprises a total of five battery projects in California and Texas.
As well as Moss Landing phases one and two it includes the 260MW/260MWh DeCordova project expected online 2022.


