# Vanadium Redox Flow Battery Plant

CAISO asset profile · https://askthegrid.com/assets/facilities/vanadium-redox-flow-battery-plant

San Diego Gas & Electric Company - San Diego County - CAISO

The Vanadium Redox Flow Battery Plant is SDG&E’s 2 MW / 8 MWh flow-battery system at Miguel Substation in Bonita, San Diego County. EIA lists generator VRF as operating in August 2026, with an operating month of June 2017. Sumitomo Electric supplied the system for a NEDO-commissioned demonstration that tested grid services and microgrid operation. The battery entered CAISO markets in 2018. Its later 2022 purchase-option milestone is distinct from the battery’s original 2017 operating start.

## Metrics

- **Nameplate capacity:** 2 MW — Canonical EIA plant baseline.
- **Registry anchor:** Plant 61107 — plant-61107
- **EIA energy capacity:** 8 MWh — August 2026 generator VRF inventory; 2 MW rated power.

## Facts

- **Technology:** Batteries
- **Operator:** San Diego Gas & Electric Company
- **Operating status:** Operating

## Related parties

- **Owner / operator:** San Diego Gas & Electric Company — Owner and operator; host utility at Miguel Substation ([source](https://www.sdge.com/))
- **Market operator:** California Independent System Operator — Wholesale electricity market operator; battery participates in CAISO markets ([source](https://www.caiso.com/))

## Sources

- [clean-coalition.org](https://clean-coalition.org/wp-content/uploads/2020/01/SDGE-Webinar-Clean-Coalition-1-29-20-min.pdf) — clean-coalition.org · public_source — Source retained for exact-record publication review.
- [sumitomoelectric.com](https://sumitomoelectric.com/id/project/v19/05) — sumitomoelectric.com · public_source — Source retained for exact-record publication review.
- [sumitomoelectric.com](https://sumitomoelectric.com/products/flow-batteries/case-studies/SDGE-Sandiego) — sumitomoelectric.com · public_source — Source retained for exact-record publication review.
- [sumitomoelectric.com](https://sumitomoelectric.com/sites/default/files/2025-11/download_documents/FBNA%20Presentation%20Slides.pdf) — sumitomoelectric.com · public_source — Source retained for exact-record publication review.
- [nedo.go.jp](https://www.nedo.go.jp/english/news/AA5en_100449.html) — nedo.go.jp · public_source — Source retained for exact-record publication review.

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Canonical page: https://askthegrid.com/assets/facilities/vanadium-redox-flow-battery-plant
Website: [San Diego Gas & Electric Company](https://www.sdge.com/)

Source: Ask the Grid — https://askthegrid.com/