Ottumwa

Coal power plant in Iowa, United States of America. Approximate location 41.0961, -92.5558.

CoalIowaUnited States of America

Ottumwa is a 726 MW coal power station in Iowa, United States of America. It is operated by Interstate Power and Light Co. Based on reported annual generation of 3,791 GWh, it can supply roughly 1.1 million homes. It ranks #920 of 10,938 United States of America power plants by installed capacity. Commissioned in 1981, it is around 45 years old — long-established. 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).

726Source-backed capacity
3,791GWh reported / yr
1,083,057homes powered
1981commissioned (~45 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0006254.

Data status

Known data

FacilityOttumwa WRI
CountryUnited States of America · Iowa WRI
Coordinates41.0961, -92.5558 WRI
FuelCoal WRI
MW installed capacity726 MW WRI source record; scope not independently normalised
OwnerInterstate Power and Light Co WRI
Commissioned1981 WRI
GWh reported / yr3,791 GWh/yr WRI

Calculated from dataset

CO₂ emissions3,790,700 t CO₂/yr calculated
Capacity rank in country#920 of 10938 calculated
Fuel-specific rank in country#314 of 802 calculated
Capacity vs country/fuel peers1.30× · 558 MW median · 802 peers calculated
Homes-powered equivalent1,083,057 calculated from reported generation
Climate10.3°C · HDD 3,256 derived from coordinates
Environmental severityC2 · 34/100 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 L100000103916); fuel: WRI source-record fuel

In context: how this plant compares

At 726 MW, Ottumwa 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.

Reported generation trend

2013: 3,363 GWh20132014: 2,632 GWh20142015: 3,856 GWh20152016: 3,709 GWh20162017: 4,019 GWh20172018: 3,736 GWh20182019: 3,791 GWh20194k GWh

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

Owner

Operated by Interstate Power and Light Co. 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 hot-summer humid continental climate (Köppen Dfa) — Northern Hemisphere, latitude 41.1°N — which shapes how much energy it can produce and how its output varies through the year.

10.3°Cannual mean temp
3,256heating degree-days (base 18°C)
488cooling degree-days (base 18°C)
230 melevation

Monthly mean temperature

J: -6 °CJF: -2 °CFM: 4 °CMA: 11 °CAM: 17 °CMJ: 22 °CJJ: 24 °CJA: 23 °CAS: 18 °CSO: 12 °CON: 4 °CND: -3 °CD24 °C

Heating degree-days here run 32% 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: 70/100 — this site sits in the top 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 mild atmospheric environment (estimated ISO 9223 class C2 — Low), with thermal cycling the leading environmental stress.

C2ISO 9223 corrosivity (indicative)
34/100environmental-severity index
30.2°Cseasonal temperature swing
425 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 #314 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 41.0961, -92.5558 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions

What type of power plant is Ottumwa?

Ottumwa is a 726 MW source-record coal power plant in Iowa, United States of America, commissioned in 1981.

How much electricity does Ottumwa generate?

Ottumwa generates about 3,791 GWh of electricity per year.

How many homes can Ottumwa power?

Its output is enough to supply roughly 1,083,057 homes.

Who operates Ottumwa?

Ottumwa is operated by Interstate Power and Light Co.

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