Stewart Mountain
Hydro power plant · Maricopa County, Arizona
Nameplate capacity
13 MW
Rank in Arizona
#140
of 200 plants
In service since
1930
March 1930
Details
- Primary fuel
- Hydro
- Technology
- Conventional Hydroelectric
- Operator
- Salt River Project
- County
- Maricopa County
- Generating units
- 1
- Share of state capacity
- 0.03%
- Rank among hydro plants in Arizona
- #9 of 11
- EIA plant code
- 150
Generating units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| SM | Conventional Hydroelectric | 13 MW | 13 MW | 1930 | 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 Arizona
| RE Bagdad Solar I LLC | Solar | 15 MW |
| Badger 1 | Solar | 15 MW |
| Davis Monthan AFB (AZ) West Airfield | Solar | 13 MW |
| Raptor Ridge | Solar | 13 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 13 MW solar plant and a 13 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 Arizona power plants · What Arizona actually generates