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Mammoth G3

Other power plant · Mono County, California

Nameplate capacity
15 MW
Rank in California
#759
of 1,897 plants
In service since
1990
December 1990

Details

Primary fuel
Other
Technology
Geothermal
Operator
Ormat Nevada Inc
County
Mono County
Generating units
3
Share of state capacity
0.01%
Rank among other plants in California
#63 of 152
EIA plant code
10479

Generating units

Individual generating units at Mammoth G3
UnitTechnologyNameplateSummerOnlineStatus
T101Geothermal5.0 MW3.3 MW1990Operating
T102Geothermal5.0 MW3.3 MW1990Operating
T103Geothermal5.0 MW3.3 MW1990Operating

Nameplate is the maximum rated output; summer capacity is what the unit can reliably deliver on a hot day, which is typically lower.

Similarly sized plants in California

Kings BeachOther15 MW
Mammoth G2Other15 MW
Morelos del SolSolar15 MW
RE Columbia Two, LLCSolar15 MW

About this data

From EIA’s inventory of operable generators, May 2026 release. Capacity is nameplate — the maximum rated output of the equipment, not what the plant actually generates over a year, which depends on how often it runs. A 15 MW solar plant and a 15 MW nuclear plant have the same entry here and produce very different amounts of electricity.

“In service since” is the earliest in-service date among the units still listed, so a site rebuilt around newer equipment can read as younger than the site itself. All California power plants · What California actually generates