Nuclear power plant in Missouri, United States of America. Approximate location 38.7589, -91.7788.
NuclearMissouriUnited States of America
Callaway is a 1,236 MW nuclear power station in Missouri, United States of America. It is operated by Union Electric Co - (MO). Based on reported annual generation of 9,190 GWh, it can supply roughly 2,625,685 homes. It ranks #221 of 9,833 United States of America power plants by installed capacity. Commissioned in 1985, it is around 41 years old — long-established. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, nuclear supplies about 17.4% 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 USA0006153.
Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).
Operated by Union Electric Co - (MO). All plants by this company →
This nuclear plant uses heat from nuclear fission to raise steam for a turbine-generator. It sits in a humid subtropical climate (Köppen Cfa) — Northern Hemisphere, latitude 38.8°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 7% 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: 53/100 — this site sits in the mid third of the power plants we cover by heating degree-days.
In colder climates, uninsulated hot equipment (boilers, turbines, valves, steam lines) loses proportionally more heat to ambient air — exactly the loss Inzonex modular insulation is designed to cut.
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.
The #42 largest nuclear power plant of 58 in United States of America by capacity.
United States of America has 58 nuclear power plants in this dataset, together about 104,233 MW of capacity.
Coordinates 38.7589, -91.7788 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
