Forsmark is a 3,446 MW nuclear power station in Uppsala, Sweden. It is operated by 65% Vattenfall; E.ON 8.5%; Mellansvensk Kraftgrupp 25.5%. Based on reported annual generation of 24,576 GWh, it can supply roughly 7.0 million homes. It ranks #2 of 178 Sweden power plants by installed capacity. Commissioned in 1980, it is around 46 years old — long-established. 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 WRI1002098.
Data status
Known data
Calculated from dataset
Not available
Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.
Data provenance
Source of the capacity and fuel values:
capacity: GEM · 2026 · L100000500073; fuel: WRI GPPD
In context: how this plant compares
Technically it is described as boiling water reactor. Nuclear plants split uranium to raise steam with no direct CO₂; they run as steady baseload with very high capacity factors and the longest operating lifetimes of any thermal plant.
Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.
Key facts
- Load factor
- 81%, from 24,576 GWh of reported generation
- Share of Sweden nuclear capacity
- 34.8% of 9,890 MW across 4 plants in this dataset
- Age among peers
- 3 of 4 dated nuclear plants in Sweden are older
Calculated from the capacity and generation records in this dataset (WRI Global Power Plant Database (CC BY 4.0)).
Reported generation trend
Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).
Owner
Operated by 65% Vattenfall; E.ON 8.5%; Mellansvensk Kraftgrupp 25.5%.
Local climate & thermal context
This nuclear plant uses heat from nuclear fission to raise steam for a turbine-generator. It sits in a warm-summer humid continental climate (Köppen Dfb) — Northern Hemisphere, latitude 60.4°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 84% 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: 91/100 — 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 moderately corrosive environment (estimated ISO 9223 class C3 — Medium), with humidity / wetness 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 #2 largest nuclear power plant of 4 in Sweden by capacity.
Sweden has 4 nuclear power plants in this dataset, together about 9,890 MW of capacity.
Nearby power plants
- Lanforsen · Hydro · 44 MW · Uppsala
- Kvarnsveden 2 · Hydro · 30 MW · Uppsala
- Alvkarleby · Hydro · 116 MW · Uppsala
- Kvarnsveden 1 · Hydro · 28 MW · Uppsala
- Hammarforsen · Hydro · 80 MW · Stockholm
- Untra · Hydro · 43 MW · Uppsala
Location
Coordinates 60.4028, 18.1744 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
Frequently asked questions
What type of power plant is Forsmark?
Forsmark is a 3,446 MW nuclear power plant in Uppsala, Sweden, commissioned in 1980.
How much electricity does Forsmark generate?
Forsmark generates about 24,576 GWh of electricity per year.
Who operates Forsmark?
Forsmark is operated by 65% Vattenfall; E.ON 8.5%; Mellansvensk Kraftgrupp 25.5%.