W R Gianelli
Hydro power plant · Merced County, California
Nameplate capacity
424 MW
Rank in California
#50
of 1,897 plants
In service since
1967
March 1967
Details
- Primary fuel
- Hydro
- Technology
- Hydroelectric Pumped Storage
- Operator
- California Dept. of Water Resources
- County
- Merced County
- Generating units
- 8
- Share of state capacity
- 0.39%
- Rank among hydro plants in California
- #5 of 244
- EIA plant code
- 448
Generating units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| 1 | Hydroelectric Pumped Storage | 53 MW | 51 MW | 1968 | Operating |
| 2 | Hydroelectric Pumped Storage | 53 MW | 50 MW | 1968 | Operating |
| 3 | Hydroelectric Pumped Storage | 53 MW | 50 MW | 1967 | Operating |
| 4 | Hydroelectric Pumped Storage | 53 MW | 50 MW | 1967 | Operating |
| 5 | Hydroelectric Pumped Storage | 53 MW | 50 MW | 1967 | Operating |
| 6 | Hydroelectric Pumped Storage | 53 MW | 50 MW | 1967 | Operating |
| 7 | Hydroelectric Pumped Storage | 53 MW | 50 MW | 1967 | Operating |
| 8 | Hydroelectric Pumped Storage | 53 MW | 50 MW | 1967 | 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
| Slate Hybrid | Solar | 440 MW |
| Panoche Energy Center | Natural gas | 432 MW |
| Watson Cogeneration | Natural gas | 405 MW |
| Kola Energy Center | Battery storage | 400 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 424 MW solar plant and a 424 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