1163 MW Geothermal operating in Sonoma, CA — California Independent System Operator
1,163 MW
Nameplate Capacity
12
Generators
units
Geothermal
Technology
1971
Operating Since
Coordinates
38.7770, -122.7450
County
Sonoma, CA
Nearby Plants
Owner data does not fully agree across sources.
EIA typically reports the operating utility, while GEM resolves to the financial owner or parent corporation. Both can be correct.
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | Geysers Power Co LLC | Geysers Power | — |
| Owner(s) | Geysers Power Co LLC | Constellation Energy | — |
| Status | Operating | operating | — |
Located in Sonoma County, California, the Geysers Unit 5-20 is a geothermal power plant with a total capacity of 1163 MW across 12 generators. The plant began operating in 1971 and is owned by Constellation Energy, with Geysers Power Co LLC as the operator. It is the largest geothermal plant in California (ranked 1 of 4) and the largest in the United States (ranked 1 of 7).
The Geysers Unit 5-20 utilizes geothermal energy as its primary fuel source. In the most recent year of reported data, the plant generated 4,314,823 MWh of electricity, achieving a capacity factor of 42.3%. The plant operates within the California Independent System Operator (CAISO) balancing authority and the Western Electricity Coordinating Council (WECC) NERC region.
Generated from EIA, GEM, and public data sources
NERC Region
WECC
Balancing Authority
California Independent System Operator
Grid Voltage
230 kV
Regulatory Status
NR
Entity Type
Independent Power Producer
Sector
IPP Non-CHP
334.3K MWh
Latest Month
4.3M MWh
Annual Generation
42.3%
Capacity Factor
No financial data available for this plant.
Market Position
ISO/RTO Market
CAISO
LMP Node
GEYSER20_7_B1
Pricing Hub
TH_NP15_GEN-APND
Location Type
Pricing Node
Node Source
Curated node match
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Last updated 2026-03-21
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