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Mariposa Energy Project

Natural gas power plant · Alameda County, California

Nameplate capacity
200 MW
Rank in California
#134
of 1,897 plants
In service since
2012
October 2012

Details

Primary fuel
Natural gas
Technology
Natural Gas Fired Combustion Turbine
Operator
Diamond Generating Corporation
County
Alameda County
Generating units
4
Share of state capacity
0.19%
Rank among natural gas plants in California
#50 of 309
EIA plant code
57483

Generating units

Individual generating units at Mariposa Energy Project
UnitTechnologyNameplateSummerOnlineStatus
CTG1Natural Gas Fired Combustion Turbine50 MW50 MW2012Operating
CTG2Natural Gas Fired Combustion Turbine50 MW50 MW2012Operating
CTG3Natural Gas Fired Combustion Turbine50 MW50 MW2012Operating
CTG4Natural Gas Fired Combustion Turbine50 MW50 MW2012Operating

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

Imperial Valley Solar, LLCSolar200 MW
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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 200 MW solar plant and a 200 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