# Melrose BESS

CAISO asset profile · https://askthegrid.com/assets/facilities/melrose-bess

## Current generation inventory

EIA plant 66281 · Inventory reporting month: 2026-08.

- batteries: 20 MW operating nameplate
- Capacity basis: operating_generator_nameplate_mw
- Source inventory: [EIA-860M workbook (preliminary)](https://www.eia.gov/electricity/data/eia860m/xls/august_generator2026.xlsx)
- Inventory retrieved: 2026-10-10T22:49:53.020309+00:00
- Filed coordinate (longitude, latitude): -117.2528, 33.207233
- OSM extract: 2026-10-09T20:21:04Z
- OSM mapped edit: 2026-01-05 14:44:54+00:00
- Map prepared: 2026-10-10T23:05:21.836879+00:00

Battery power (MW) and stored energy (MWh) are separate measures. Shared physical-site membership does not establish electrical connectivity, settlement or a common export limit.

## Reviewed overview

Melrose BESS is SDG&E’s 20 MW / 80 MWh battery installation at Melrose Substation in Vista, California. Two 10 MW units provide a four-hour project configuration. SDG&E’s construction notice describes 126 lithium iron phosphate battery cubes and nodes; the CPUC identified Fluence as EPC contractor. EIA’s August 2026 inventory records March 2024 as the operating month for both generators.

## Profile

- **SDG&E role:** Utility owner and operator, rather than only a power purchaser or transmission neighbor.

## Reviewed metrics

- **Project power / energy:** 20 MW / 80 MWh — 4-hour project design reported by the utility or supplier; power is MW and stored energy is MWh.
- **Nameplate capacity:** 20 MW — Canonical EIA plant baseline.
- **Registry anchor:** Plant 66281 — plant-66281

## Facts

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

## Related parties

- **Owner / operator:** San Diego Gas & Electric Company — Owner and operator ([source](https://www.sdge.com/))
- **EPC contractor / O&M provider:** Fluence Energy, LLC — EPC contractor and long-term service and maintenance provider ([source](https://fluenceenergy.com/))
- **Balancing authority / market operator:** California Independent System Operator (CAISO) — Wholesale market operator and balancing authority ([source](https://www.caiso.com/))

## Sources

- [docs.cpuc.ca.gov](https://docs.cpuc.ca.gov/PublishedDocs/Published/G000/M449/K525/449525225.pdf) — docs.cpuc.ca.gov · authoritative — Source retained for exact-record publication review.
- [docs.cpuc.ca.gov](https://docs.cpuc.ca.gov/PublishedDocs/Published/G000/M451/K413/451413037.PDF) — docs.cpuc.ca.gov · authoritative — Source retained for exact-record publication review.
- [docs.cpuc.ca.gov](https://docs.cpuc.ca.gov/PublishedDocs/SupDoc/A2405007/7811/544870396.pdf) — docs.cpuc.ca.gov · authoritative — Source retained for exact-record publication review.
- [mbrweb.ferc.gov](https://mbrweb.ferc.gov/SearchlkpEIA/Index?page=757) — mbrweb.ferc.gov · authoritative — Source retained for exact-record publication review.
- [sdge.com](https://sdge.com/sites/default/files/regulatory/SDGE-10_Electric_Generation_Darren_Weim_Direct_6156_6157.pdf) — sdge.com · public_source — Source retained for exact-record publication review.
- [sdge.com](https://www.sdge.com/sites/default/files/Melrose%20Substation%20Battery%20Storage%20Project%20Customer%20Notification%2008.05.22.pdf) — sdge.com · public_source — Source retained for exact-record publication review.

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Canonical page: https://askthegrid.com/assets/facilities/melrose-bess
Website: [San Diego Gas & Electric Company](https://www.sdge.com/)

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