7th largest plant in Missouri · 279th nationally
Sioux is a coal power plant in Missouri with a nameplate capacity of 1,099 MW. It generates roughly 3.1M MWh per year — enough to power about 290,524 average U.S. homes.
Its capacity factor of 32% reflects intermittent or peaking operation. At 2316 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 (1,099 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 | Sioux |
|---|---|
| Operator | Union Electric Co - (Mo) |
| City | West Alton |
| County | St Charles County |
| State | Missouri |
| ZIP | 63386 |
| Coordinates | 38.91548, -90.29025 |
This plant highlighted in navy-ringed pin; other generators within 25 miles shown as fuel-colored dots.
| ID | Technology | Fuel | Capacity | Status | Online |
|---|---|---|---|---|---|
| 1 | Conventional Steam Coal | Subbituminous Coal | 550 MW | Operating | 1967 |
| 2 | Conventional Steam Coal | Subbituminous Coal | 550 MW | Operating | 1968 |
| CO₂ | 3.5M metric tons |
|---|---|
| SO₂ | 902 metric tons |
| NOₓ | 3.5k metric tons |
| CO₂ Rate | 2316 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 | SERC |
|---|---|
| Balancing Authority | Midcontinent Independent Transmission System Operator, Inc.. |
Coal plants burn pulverized coal to boil water and spin steam turbines. They emit substantial CO₂, SO₂, and NOₓ along with mercury and particulate matter. Modern units include scrubbers and selective catalytic reduction; older units are increasingly being retired or converted to natural gas as economics shift.