Sioux
Sioux is a 1 GW coal power plant in St Charles County, Missouri, operated by Union Electric Co - (MO). EIA-860M lists 2 generating units here, inside MISO. Its units entered service between 1967 and 1968.
As of 2026-07 (inventory dated 2026-07-31) · EIA-860M Preliminary Monthly Electric Generator Inventory · eia.gov/…/july_generator2026.xlsx · eia.gov/…/eia860m
- Nameplate capacity
- 1,099.4 MW
- 974 MW net summer
- Generating units
- 2
- In service
- 1967–1968
- EIA plant ID
- 2107
Where it is
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- County
- St Charles County, Missouri
- Coordinates
- 38.9155, -90.2902
- Balancing authority
- MISO
- Sector
- Electric Utility
Units, technology and status
- Operator of record
- Union Electric Co - (MO)
- Primary energy source
- Coal
- Technologies
- Conventional Steam Coal
- Status
- Operating
Sioux: FAQ
- Where is Sioux?
- In St Charles County, Missouri (MO). The map on this page is placed at the coordinates EIA files for the plant, which locate the site rather than any individual unit.
- How big is Sioux?
- 1 GW of nameplate capacity across 2 units, as of the EIA-860M release for 2026-07.
- Who owns Sioux?
- EIA-860M names Union Electric Co - (MO) as the reporting entity. That is the operator of record on the survey, which is not always the ultimate owner.
- Is this the same as Sioux LLC?
- Probably, but EIA-860M does not say. The survey records a plant name and a reporting entity — Union Electric Co - (MO) here — not the project company that holds the asset. Project companies are commonly registered as an LLC carrying the plant's name, so a search for "Sioux LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.
- Is Sioux still running?
- EIA-860M files it as "Operating" for 2026-07. Statuses change monthly, and this page follows the monthly release.