36th largest plant in Pennsylvania · 672nd nationally
Allegheny Energy Units 3 4 & 5 is a natural gas power plant in Pennsylvania with a nameplate capacity of 556 MW. It generates roughly 4.5M MWh per year — enough to power about 426,704 average U.S. homes.
Its capacity factor of 92% means it runs nearly around-the-clock as baseload generation. At 750 lb CO₂/MWh, its emission rate sits below the national grid average of roughly 800 lb/MWh.
Ghost bars are each month's theoretical maximum (556 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 | Allegheny Energy Units 3 4 & 5 |
|---|---|
| Operator | Springdale Energy Llc |
| City | Springdale |
| County | Allegheny County |
| State | Pennsylvania |
| ZIP | 15144 |
| Coordinates | 40.54528, -79.76861 |
This plant highlighted in navy-ringed pin; other generators within 25 miles shown as fuel-colored dots.
| ID | Technology | Fuel | Capacity | Status | Online |
|---|---|---|---|---|---|
| UNT5 | Natural Gas Fired Combined Cycle | Natural Gas | 188 MW | Operating | 2003 |
| UNT3 | Natural Gas Fired Combined Cycle | Natural Gas | 184 MW | Operating | 2003 |
| UNT4 | Natural Gas Fired Combined Cycle | Natural Gas | 184 MW | Operating | 2003 |
| CO₂ | 1.7M metric tons |
|---|---|
| SO₂ | 8 metric tons |
| NOₓ | 114 metric tons |
| CO₂ Rate | 750 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 | RFC |
|---|---|
| Balancing Authority | Pjm Interconnection, Llc |
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.