Sioux

Coal power plant in Illinois, United States of America. Approximate location 38.9155, -90.2902.

CoalIllinoisUnited States of AmericaCO₂ measured

Sioux is a 1,099 MW coal power station in Illinois, United States of America. It is operated by Union Electric Co - (MO). Based on reported annual generation of 3,886 GWh, it can supply roughly 1.1 million homes. It ranks #596 of 10,938 United States of America power plants by installed capacity. Commissioned in 1967, it is around 59 years old — an older, legacy facility. Its annual emissions of 3,233,285 t CO₂/yr (US EPA GHGRP) are equivalent to about 754k cars driven for a year. In context, coal supplies about 16.3% of United States of America's electricity; the national grid averages 384 gCO₂/kWh (43.0% low-carbon) (2025).

1,099Source-backed capacity
3,886GWh reported / yr
1,110,171homes powered
3,233,285t CO₂ / yr (US EPA GHGRP)
1967commissioned (~59 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0002107.

Data status

Known data

FacilitySioux WRI
CountryUnited States of America · Illinois WRI
Coordinates38.9155, -90.2902 WRI
FuelCoal WRI
MW installed capacity1,099 MW WRI source record; scope not independently normalised
OwnerUnion Electric Co - (MO) WRI
Commissioned1967 WRI
GWh reported / yr3,886 GWh/yr WRI
CO₂ emissions3,233,285 t CO₂/yr measured · US EPA GHGRP

Calculated from dataset

Capacity rank in country#596 of 10938 calculated
Fuel-specific rank in country#226 of 802 calculated
Capacity vs country/fuel peers1.97× · 558 MW median · 802 peers calculated
Homes-powered equivalent1,110,171 calculated from reported generation
Climate13.1°C · HDD 2,520 derived from coordinates
Environmental severityC3 · 36/100 derived from coordinates

Not available

TechnologyNot available not in dataset
GWh reported / yrNot available not in dataset

Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.

Data provenance

The capacity and/or fuel fields on this page include a source-backed provenance label from GEM, an official registry, Wikidata, OSM, or a cross-source match.

capacity: GEM tracker 2026 (location L100000104028); fuel: WRI source-record fuel

In context: how this plant compares

At 1,099 MW, Sioux is well above the median coal plant in United States of America (558 MW). Coal plants burn pulverised coal to raise high-pressure steam for a turbine; they run as baseload but are the most carbon-intensive mainstream source and the first targeted for retirement or efficiency retrofits.

Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.

3,233,285 t CO₂/yr — in everyday terms

This facility's annual emissions are roughly equivalent to:

754kpassenger cars driven for a year
422khomes' yearly energy use
54 milliontree seedlings grown 10 years to absorb it

Equivalencies via US EPA Greenhouse Gas Equivalencies; emissions per US EPA GHGRP (measured for US EPA/EU ETS, modelled for Climate TRACE).

Reported generation trend

2013: 5,080 GWh20132014: 4,964 GWh20142015: 4,495 GWh20152016: 0 GWh20162017: 0 GWh20172018: 0 GWh20182019: 3,886 GWh20195k GWh

Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).

Owner

Operated by Union Electric Co - (MO). All plants by this company →

Local climate & thermal context

This coal plant burns coal to raise high-pressure steam that spins a turbine-generator. It sits in a humid subtropical climate (Köppen Cfa) — Northern Hemisphere, latitude 38.9°N — which shapes how much energy it can produce and how its output varies through the year.

13.1°Cannual mean temp
2,520heating degree-days (base 18°C)
746cooling degree-days (base 18°C)
157 melevation

Monthly mean temperature

J: -2 °CJF: 1 °CFM: 7 °CMA: 13 °CAM: 19 °CMJ: 24 °CJJ: 26 °CJA: 25 °CAS: 21 °CSO: 14 °CON: 7 °CND: 1 °CD26 °C

Heating degree-days here run 3% above the median power plant in this dataset — a proxy for how much extra energy heated equipment must replace through its surfaces in winter.

Climate heat-demand index: 51/100 — this site sits in the mid third of the power plants we cover by heating degree-days.

Climate normals: WorldClim 2.1 (1970–2000 monthly normals, 10 arc-min, CC BY 4.0); zone: Köppen-Geiger world climate classification (Kottek et al. 2006, 0.5° grid). Degree-days & heat-demand index computed by PowerAtlas — a modelled heat-demand proxy, not a measured site figure.

Site climate & environmental severity

For a plant’s outdoor hardware — heat-recovery steam generators (HRSG), expansion joints, valves, flanges and their insulation — the local climate sets how fast unprotected steel and coatings degrade. This site sits in a moderately corrosive environment (estimated ISO 9223 class C3 — Medium), with humidity / wetness the leading environmental stress.

C3ISO 9223 corrosivity (indicative)
36/100environmental-severity index
27.9°Cseasonal temperature swing
436 kmdistance to coast

Higher environmental severity is exactly where protective removable insulation pays back most: a sheltered micro-climate slows corrosion, UV and thermal-cycling damage and extends outdoor hardware service life. This is an indicative site-climate context — not a condition assessment of any specific plant or operator.

Indicative estimate via the ISO 9223:2012 informative method (atmospheric corrosivity from temperature, time-of-wetness and airborne salinity), using WorldClim climate normals, the Köppen-Geiger class and coast distance. Indicative, not a measured corrosion rate.

How it compares & nearby plants

The #226 largest coal power plant of 802 in United States of America by capacity.

United States of America has 802 coal power plants in this dataset, together about 621,194 MW of capacity.

Nearby power plants

Location

Coordinates 38.9155, -90.2902 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions

What type of power plant is Sioux?

Sioux is a 1,099 MW source-record coal power plant in Illinois, United States of America, commissioned in 1967.

How much electricity does Sioux generate?

Sioux generates about 3,886 GWh of electricity per year.

How many homes can Sioux power?

Its output is enough to supply roughly 1,110,171 homes.

Who operates Sioux?

Sioux is operated by Union Electric Co - (MO).

How much CO₂ does Sioux emit?

Sioux has measured emissions of about 3,233,285 tonnes of CO₂ per year (US EPA GHGRP).

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