Harquahala Generating Project
Natural gas power plant · Maricopa County, Arizona
Nameplate capacity
1,277 MW
Rank in Arizona
#5
of 200 plants
In service since
2004
June 2004
Details
- Primary fuel
- Natural gas
- Technology
- Natural Gas Fired Combined Cycle
- Operator
- New Harquahala Generating Co, LLC
- County
- Maricopa County
- Generating units
- 6
- Share of state capacity
- 2.99%
- Rank among natural gas plants in Arizona
- #2 of 33
- EIA plant code
- 55372
Generating units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| CTG1 | Natural Gas Fired Combined Cycle | 282 MW | 240 MW | 2004 | Operating |
| CTG2 | Natural Gas Fired Combined Cycle | 282 MW | 227 MW | 2004 | Operating |
| CTG3 | Natural Gas Fired Combined Cycle | 282 MW | 226 MW | 2004 | Operating |
| STG1 | Natural Gas Fired Combined Cycle | 144 MW | 120 MW | 2004 | Operating |
| STG2 | Natural Gas Fired Combined Cycle | 144 MW | 115 MW | 2004 | Operating |
| STG3 | Natural Gas Fired Combined Cycle | 144 MW | 116 MW | 2004 | 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
| Santan | Natural gas | 1,326 MW |
| Glen Canyon Dam | Hydro | 1,312 MW |
| West Phoenix | Natural gas | 1,207 MW |
| Red Hawk | Natural gas | 1,127 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 1,277 MW solar plant and a 1,277 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