Mammoth G1 — Plant Summary
- EIA Plant ID
- 10480
- Capacity
- 10 MW
- Primary Fuel
- Geothermal
- Technology
- Geothermal
- Status
- Operating
- Location
- Mono, CA
- Operating Since
- 1984
- Generators
- 2
- Operator
- Ormat Nevada Inc
- Parent Company
- —
- Annual Generation
- 59,620 MWh
- Capacity Factor
- 67.9%
- Balancing Authority
- California Independent System Operator
- ISO/RTO
- CAISO
- NERC Region
- WECC
Mammoth G1
OperatingGeothermal
Ranked #32 of 33 Geothermal plants in CA#66 of 70 nationally
10 MW Geothermal operating in Mono, CA — California Independent System Operator
EIAGEMWD
10 MW
Nameplate Capacity
2
Generators
units
Geothermal
Technology
1984
Operating Since
Location
Coordinates
37.6451, -118.9143
County
Mono, CA
Nearby Plants
- CD4Geothermal44.4 MW · 0.2 km
- Mammoth G3Geothermal15 MW · 0.4 km
- Mammoth G2Geothermal15 MW · 0.5 km
Ownership & Operator
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 | Ormat Nevada Inc | Ormat Technology Inc [100%] | — |
| Owner(s) | Mammoth Pacific LP | Ormat Technology Inc [100%] | — |
| Status | Operating | operating | — |
Ownership Chain
GEM identifies the owner as Ormat Technology Inc [100%]
This entity is not yet in the GEM ownership database — chain unavailable.
About
Mammoth G1 is a 10 MW geothermal power plant located in Mono County, California. The plant began operating in 1984 and is owned and operated by Ormat Nevada Inc. It consists of two generators utilizing geothermal technology. The plant operates within the California Independent System Operator (CAISO) balancing authority and the Western Electricity Coordinating Council (WECC) NERC region.
In the most recent year of data, Mammoth G1 generated 59,620 MWh of electricity, achieving a capacity factor of 67.9%. The plant ranks 31st out of 33 power plants in California and 65th out of 70 nationally.
Generated from EIA, GEM, and public data sources
Engineering & Generators
Grid Context
NERC Region
WECC
Balancing Authority
California Independent System Operator
Grid Voltage
33 kV
Regulatory Status
NR
Entity Type
Independent Power Producer
Sector
IPP Non-CHP
Generation
5.3K MWh
Latest Month
59.6K MWh
Annual Generation
67.9%
Capacity Factor
Jan 2022 – Dec 2024
Financial Data
No financial data available for this plant.
Pricing & Market Data
HIGH confidencePoint of Interconnection
Nearest Substation
Mommoth Pacific 1
Substation Distance
0.154 km
Coord Source
OSM spatial
Market Position
ISO/RTO Market
CAISO
LMP Node
CONTROLX_1_N009
Pricing Hub
TH_SP15_GEN-APND
Secondary Zone
TH_NP15_GEN-APND
Location Type
Pricing Node
Node Source
Curated node match
News & Articles (2)Beta
Deals·project finance
Ormat Technologies signs finance deal for Indonesian power plant
Ormat Technologies, a US-based holding company, announced that it signed a $1.17 billion financing agreement with an Indonesian group that is building the huge...
Ormat Technologies (developer)
The Times of Israel·11 years ago
Industry·corporate
Top Israeli exporter is top green company too
Ormat Technologies, a maker of environmental energy solutions, is Israel's Exporter of the Year for 2013.
Ormat Technologies (developer)
The Times of Israel·12 years ago
Last updated 2026-03-26
View all articles