Dion R Holm — Plant Summary
- EIA Plant ID
- 380
- Capacity
- 180.2 MW
- Primary Fuel
- Hydro
- Technology
- Conventional Hydroelectric
- Status
- Operating
- Location
- Tuolumne, CA
- Operating Since
- 1960
- Generators
- 2
- Operator
- City & County of San Francisco
- Parent Company
- —
- Annual Generation
- 578,813 MWh
- Capacity Factor
- 36.9%
- Balancing Authority
- California Independent System Operator
- ISO/RTO
- CAISO
- NERC Region
- WECC
Dion R Holm
OperatingHydro
Ranked #16 of 247 Hydro plants in CA#103 of 1454 nationally
180.2 MW Hydro operating in Tuolumne, CA — California Independent System Operator
EIAGEMWD
180.2 MW
Nameplate Capacity
2
Generators
units
Conventional Hydroelectric
Technology
1960
Operating Since
Location
Ownership & Operator
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | City & County of San Francisco | City & County of San Francisco | — |
| Owner(s) | City & County of San Francisco | City & County of San Francisco [100%] | — |
| Status | Operating | operating | — |
Ownership Chain
GEM identifies the owner as City & County of San Francisco [100%]
This entity is not yet in the GEM ownership database — chain unavailable.
About
Dion R Holm Generating Station is a 180.2 MW hydroelectric power plant located in Tuolumne County, California. The plant began operating in 1960 and utilizes conventional hydroelectric technology. It consists of 2 generators and is owned and operated by the City & County of San Francisco.
The plant's primary fuel source is water (WAT). In the most recent year of reported data, Dion R Holm generated 578,813 MWh of electricity, achieving a capacity factor of 36.9%. The plant operates within the California Independent System Operator (CAISO) balancing authority and the Western Electricity Coordinating Council (WECC) NERC region. Dion R Holm ranks as the 16th largest hydroelectric plant out of 42 in California, and 103rd out of 194 nationally.
Generated from EIA, GEM, and public data sources
Engineering & Generators
Grid Context
NERC Region
WECC
Balancing Authority
California Independent System Operator
Grid Voltage
230 kV
Regulatory Status
RE
Entity Type
Municipal
Sector
Electric Utility
Generation
54.9K MWh
Latest Month
578.8K MWh
Annual Generation
36.9%
Capacity Factor
Jan 2023 – Dec 2025
Financial Data
No financial data available for this plant.
Pricing & Market Data
HIGH confidencePoint of Interconnection
Nearest Substation
Early Intake Switchyard · 230 kV
Substation Distance
< 10 km
Operator
San Francisco Public Utilities Commission
Coord Source
OSM spatial
Market Position
ISO/RTO Market
CAISO
LMP Node
INTKEP_2_UNITS-APND
Pricing Hub
TH_NP15_GEN-APND
Location Type
Aggregated Node
Node Source
EIA-860 direct report
News & Articles (1)Beta