Calistoga Resiliency Center (CRC)

Executive Overview

The Calistoga Resiliency Center (CRC) is an 8.5 MW / 293 MWh hybrid battery and hydrogen fuel cell microgrid developed by Energy Vault for Pacific Gas and Electric (PG&E) in Calistoga, Napa County, California — the world's first ultra-long duration hybrid battery + hydrogen energy storage community microgrid. Energy Vault and PG&E announced successful completion in 2025. The system provides at least 48 continuous hours of zero-emission backup power to approximately 1,600 PG&E customers in downtown Calistoga during Public Safety Power Shutoff (PSPS) events caused by wildfire risk, replacing diesel generators. Total project financing was $28 million including the sale of the Investment Tax Credit. The agreement between Energy Vault and PG&E runs for 10.5 years. PG&E has deployed 13 distribution microgrids since 2021; Calistoga is the largest and the first fully renewable system. The microgrid participates in CAISO markets and sells power to PG&E outside of PSPS events.

How It Works & Differentiation

The CRC integrates four lithium-ion battery enclosures (B-VAULT™) with six hydrogen fuel cell units (H-VAULT™), all coordinated by Energy Vault's VaultOS™ energy management software. During outages, the batteries respond instantly while the hydrogen fuel cells ramp up to provide sustained multi-day power. The 80,000-gallon cryogenic hydrogen tank is periodically refilled to sustain operations. The system is black-start capable, produces zero point-source greenhouse gas emissions, and is fully compliant with California's Renewable Portfolio Standard. The key differentiator versus existing California community microgrids is duration: most PSPS events last 12–48 hours, and no prior system could provide zero-emission power for the full event window without interim diesel generation.

Commercialization & Traction

The CRC is Energy Vault's first commercial deployment of the H-VAULT™ / B-VAULT™ hybrid platform. The CPUC ordered on January 21, 2021 that at least one clean microgrid be developed for PSPS resilience; the CRC satisfies that mandate. CPUC criteria require clean microgrids to cost less than twice the diesel alternative. A multi-property microgrid tariff was finalised by CPUC in December 2024, streamlining regulatory approval for future deployments. PG&E committed up to $43 million to fund nine new community microgrids in the North Coast region in 2025, establishing a clear pipeline.

Scalability & Strategic Context

California has approximately 12,000 communities at elevated wildfire risk across PG&E, SCE, and SDG&E service territories, and current diesel microgrid infrastructure is inadequate for multi-day PSPS events that are becoming more frequent. The CRC demonstrates that clean long-duration storage can meet PSPS reliability requirements at commercially procurable cost. Energy Vault's VaultOS™ software is technology-agnostic — capable of managing any combination of hydrogen, batteries, solar, and other assets — making the Calistoga configuration replicable with any compatible hardware. The 48-hour performance specification directly addresses the duration gap that disqualified lithium-ion-only microgrids from PSPS backup applications.