Oskarshamn is a 2,603 MW nuclear power station in Kalmar, Sweden. It is operated by OKG (Uniper / Fortum). Based on reported annual generation of 11,074 GWh, it can supply roughly 3,163,914 homes. It ranks #3 of 168 Sweden power plants by installed capacity. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, nuclear supplies about 27.6% of Sweden's electricity; the national grid averages 35 gCO₂/kWh (98.8% low-carbon) (2025).
Plant data: WRI Global Power Plant Database (CC BY 4.0), id WRI1002168.
Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).
Operated by OKG (Uniper / Fortum).
This nuclear plant uses heat from nuclear fission to raise steam for a turbine-generator. It sits in a temperate oceanic climate (Köppen Cfb) — Northern Hemisphere, latitude 57.4°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 58% 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: 83/100 — this site sits in the top 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 #3 largest nuclear power plant of 3 in Sweden by capacity.
Sweden has 3 nuclear power plants in this dataset, together about 9,762 MW of capacity.
Coordinates 57.413, 16.6683 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
