2nd largest plant in Arizona · 90th nationally
Gila River Power Block 4 is a natural gas power plant in Arizona with a nameplate capacity of 1,857 MW. It generates roughly 7.4M MWh per year — enough to power about 703,880 average U.S. homes.
Its capacity factor of 45% puts it in the middle range — running steadily but not full-time. At 1207 lb CO₂/MWh, its emission rate sits above the national grid average of roughly 800 lb/MWh.
Ghost bars are each month's theoretical maximum (1,857 MW nameplate × hours in the month). Filled bars are actual net generation reported to EIA Form 923. The gap between them is capacity factor made visible.
| Plant Name | Gila River Power Block 4 |
|---|---|
| Operator | Salt River Project |
| City | Gila Bend |
| County | Maricopa County |
| State | Arizona |
| ZIP | 85337 |
| Coordinates | 32.97500, -112.69440 |
This plant highlighted in navy-ringed pin; other generators within 25 miles shown as fuel-colored dots.
| ID | Technology | Fuel | Capacity | Status | Online |
|---|---|---|---|---|---|
| ST12 | Natural Gas Fired Combined Cycle | Natural Gas | 271 MW | Operating | 2003 |
| CTG7 | Natural Gas Fired Combined Cycle | Natural Gas | 174 MW | Operating | 2003 |
| CTG8 | Natural Gas Fired Combined Cycle | Natural Gas | 174 MW | Operating | 2003 |
| CO₂ | 4.5M metric tons |
|---|---|
| SO₂ | 23 metric tons |
| NOₓ | 305 metric tons |
| CO₂ Rate | 1207 lb/MWh |
Annual totals and CO₂ rate reported by EPA eGRID for 2023. Reference averages are approximate U.S.-wide figures from the same dataset.
| NERC Region | WECC |
|---|---|
| Balancing Authority | Salt River Project |
Natural gas plants are the workhorse of the modern grid. Combined-cycle units achieve very high efficiency and can ramp up and down quickly to balance variable renewables. They emit roughly half the CO₂ per MWh of coal and far less of other pollutants, but they still release upstream methane during fuel extraction.