Ottumwa Generating Station — United States of America

Ottumwa Generating Station is a 725.9 MW coal power station in Iowa, United States of America. It is operated by Interstate Power and Light Co [48%]; MidAmerican Energy Co [52%]. Based on its capacity (estimated), it can supply roughly 908k homes (estimated). It ranks #864 of 10,884 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).

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

Data provenance

Source of the capacity and fuel values:

capacity: GEM · 2026 · L100000103916; fuel: GEM GCPT

In context: how this plant compares

At 725.9 MW, Ottumwa Generating Station is well above the median coal plant in United States of America (558 MW). Technically it is described as subcritical. 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.

Key facts

Share of United States of America coal capacity

0.1% of 621,194 MW across 802 plants in this dataset

Age among peers

477 of 745 dated coal plants in United States of America are older

Calculated from the capacity and generation records in this dataset (WRI Global Power Plant Database (CC BY 4.0)).

Capacity vs largest coal plants in United States of America

Installed capacity (MW), WRI Global Power Plant Database (CC BY 4.0).

Owner

Operated by Interstate Power and Light Co [48%]; MidAmerican Energy Co [52%].

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.

Monthly mean temperature

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

This site sits in a mild atmospheric environment (estimated ISO 9223 class C2 — Low), with thermal cycling the leading environmental stress.

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 #315 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

• Ottumwa · Coal · 725.9 MW · Iowa
• Cargill Corn Milling Division · Gas · 40 MW · Iowa
• Ottumwa City of · Hydro · 3.2 MW · Iowa
• Prairie Wind Farm · Wind · 168 MW · Iowa
• Bloomfield Municipal Utilities Solar · Solar · 1.6 MW · Iowa
• Bloomfield · Gas · 8.5 MW · Iowa

Location

Coordinates 41.097728, -92.554939 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions