52nd largest plant in Arizona · 2116th nationally
Horse Mesa is a hydroelectric power plant in Arizona with a nameplate capacity of 130 MW. It generates roughly 127.6k MWh per year — enough to power about 12,149 average U.S. homes.
Its capacity factor of 11% reflects intermittent or peaking operation.
| Plant Name | Horse Mesa |
|---|---|
| Operator | Salt River Project |
| City | Apache Junction |
| County | Maricopa County |
| State | Arizona |
| ZIP | 85119 |
| Coordinates | 33.59070, -111.34400 |
This plant highlighted in navy-ringed pin; other generators within 25 miles shown as fuel-colored dots.
| ID | Technology | Fuel | Capacity | Status | Online |
|---|---|---|---|---|---|
| HM4 | Hydroelectric Pumped Storage | Water | 99.8 MW | Operating | 1927 |
| HM3 | Conventional Hydroelectric | Water | 11.7 MW | Operating | 1927 |
| HM1 | Conventional Hydroelectric | Water | 9.9 MW | Operating | 1927 |
| HM2 | Conventional Hydroelectric | Water | 9.9 MW | Operating | 1927 |
| NERC Region | WECC |
|---|---|
| Balancing Authority | Salt River Project |
Hydroelectric plants spin turbines using falling or flowing water — typically from a dam-impounded reservoir. They are dispatchable, long-lived, and emission-free at the point of generation, though large reservoirs can disrupt rivers and ecosystems and methane can be released from flooded vegetation.