Nameplate capacity
131 MW
Rank in Arizona
#75
of 200 plants
In service since
1927
April 1927
Details
- Primary fuel
- Hydro
- Technology
- Hydroelectric Pumped Storage
- Operator
- Salt River Project
- County
- Maricopa County
- Generating units
- 4
- Share of state capacity
- 0.31%
- Rank among hydro plants in Arizona
- #4 of 11
- EIA plant code
- 145
Generating units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| HM4 | Hydroelectric Pumped Storage | 100 MW | 119 MW | 1927 | Operating |
| HM3 | Conventional Hydroelectric | 12 MW | 12 MW | 1927 | Operating |
| HM1 | Conventional Hydroelectric | 9.9 MW | 10 MW | 1927 | Operating |
| HM2 | Conventional Hydroelectric | 9.9 MW | 10 MW | 1927 | 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
| Sun Streams 2 | Solar | 150 MW |
| Yuma Solar + Storage | Battery storage | 140 MW |
| Arlington Valley Solar Energy II | Solar | 129 MW |
| Arlington Valley Solar Energy I | Solar | 127 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 131 MW solar plant and a 131 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