The California Energy Commission has issued a $31 million grant to build a 60 MWh long-duration energy storage system that is expected to provide backup power to the Viejas Tribe of Kumeyaay Indians and bolster the reliability of the energy system statewide.

More than 4 GW of battery storage has been installed in the California Independent System Operator footprint, and the state projects that it would need another 48 GW of battery storage and 4 GW of long-duration storage by 2045. This project is the first to be awarded under the state’s $140 million long-Source: California Energy Commissionduration energy storage program.

The 60 MWh system, considered one of the largest in the U.S., will be developed by Indian Energy, a Native American-owned microgrid developer. In addition to providing the Viejas tribe with renewable backup power during outages, it will allow the tribe to reduce electricity use from the grid when the state needs more resources.

The project will include around 30,000 solar panels, with a 15 MW output and the 60 MWh of long-duration storage. This includes a 10 MWh vanadium redox flow battery from Invinity, which will be paired with a 35 MWh, 10-hour energy storage system from Eos.

The remaining 15 MWh of storage will also be non-lithium-ion technologies and will be provided by the tribe at a later date. The initial 45 MWh are expected to come online by the summer of 2023, with the entire project online by summer of 2024.