Mammoth Pool
Hydro power plant · Madera County, California
Nameplate capacity
190 MW
Rank in California
#140
of 1,897 plants
In service since
1960
March 1960
Details
- Primary fuel
- Hydro
- Technology
- Conventional Hydroelectric
- Operator
- Southern California Edison Co
- County
- Madera County
- Generating units
- 2
- Share of state capacity
- 0.18%
- Rank among hydro plants in California
- #13 of 244
- EIA plant code
- 344
Generating units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| 1 | Conventional Hydroelectric | 95 MW | 95 MW | 1960 | Operating |
| 2 | Conventional Hydroelectric | 95 MW | 95 MW | 1960 | Operating |
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
| Sandrini Solar 100 | Solar | 195 MW |
| Procter & Gamble Power Plant | Natural gas | 193 MW |
| Manzana Wind LLC | Wind | 189 MW |
| Blythe Solar IV, LLC | Solar | 184 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 190 MW solar plant and a 190 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