Energy Vault Holdings has started construction of a utility-scale green hydrogen plus battery ultra-long duration energy storage system (BH-ESS) with 293 MWh of dispatchable carbon-free energy, according to a news release.
Construction of the BH-ESS, which is being developed for Pacific Gas and Electric Company (PG&E) on less than one acre of land in the Northern California City of Calistoga, is expected to be completed by the end of 2Q24.
Upon completion, the BH-ESS, dubbed the Calistoga Resiliency Center, will be the first-of-its-kind utility-scale green hydrogen energy storage project in the United States. The battery portion of the system will be used to support grid forming and black start capabilities.
The system will be prepared to power downtown Calistoga and the surrounding area for up to 48 hours during potential Public Safety Power Shutoffs, which occur when the powerlines serving the surrounding area must be turned off for safety due to high wildfire risk. PG&E’s proposal for the system was approved by the California Public Utilities Commission in April.
Energy Vault’s BH-ESS will replace the traditional mobile diesel generators currently used to energize PG&E’s Calistoga microgrid during PSPS events in the area. The project represents a major advance in community-scale microgrid development and a significant step toward realizing the CPUC’s vision of cleaner forms of microgrid generation.
The energy storage system will be owned, operated and maintained by Energy Vault while providing dispatchable power under a long-term tolling agreement with PG&E. Under the 10.5-year agreement, Energy Vault will provide “Distributed Generation-Enabled Microgrid Services” – a type of energy service that involves using grid-forming generation and storage resources, to provide energy, fault current contribution and to regulate voltage and frequency within the utility’s established parameters to enable the islanding of the Calistoga microgrid during PSPS outages. The solution is designed to operate during PSPS events, serving all the load within a safe-to-energize area in the City of Calistoga, including critical facilities such as fire and police stations, and shared services in the downtown and surrounding area.
