Ossauskoski is a 121 MW hydro power station in Lapland, Finland. It is operated by Kemijoki Oy. Based on its capacity (estimated), it can supply roughly 121k homes (estimated). It ranks #33 of 203 Finland power plants by installed capacity. Commissioned in 1965, it is around 61 years old — an older, legacy facility. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, hydro supplies about 15.1% of Finland's electricity; the national grid averages 57 gCO₂/kWh (96.3% low-carbon) (2025).
Plant data: WRI Global Power Plant Database (CC BY 4.0), id WRI1002476.
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: Wikidata P2109; fuel: WRI GPPD
In context: how this plant compares
At 121 MW, Ossauskoski is well above the median hydro plant in Finland (8.5 MW). Hydropower converts the energy of falling or flowing water into electricity; output depends on rainfall and reservoir level, and large dams also provide grid balancing and storage.
Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.
Key facts
- Share of Finland hydro capacity
- 5.1% of 2,386 MW across 95 plants in this dataset
- Age among peers
- 17 of 24 dated hydro plants in Finland are older
Calculated from the capacity and generation records in this dataset (WRI Global Power Plant Database (CC BY 4.0)).
Capacity vs largest hydro plants in Finland
Installed capacity (MW), WRI Global Power Plant Database (CC BY 4.0).
Owner
Operated by Kemijoki Oy. All plants by this company →
Local climate & thermal context
This hydro plant converts the energy of falling or flowing water through hydro turbines. It sits in a subarctic (boreal) climate (Köppen Dfc) — Northern Hemisphere, latitude 66.1°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 154% 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: 99/100 — 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 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 #5 largest hydro power plant of 95 in Finland by capacity.
Finland has 95 hydro power plants in this dataset, together about 2,386 MW of capacity.
Nearby power plants
- Tornio · Biomass · 39.3 MW · Lapland
- Tornio tv · Wind · 28.8 MW · Lapland
- Hietamankoski · Hydro · 6.7 MW · Lapland
- Kemi · Biomass · 75 MW · Lapland
- Kemi Ajos · Wind · 3 MW · Lapland
- Veitsiluoto · Biomass · 90 MW · Lapland
Location
Coordinates 66.0833, 24.8 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
Frequently asked questions
What type of power plant is Ossauskoski?
Ossauskoski is a 121 MW hydro power plant in Lapland, Finland, commissioned in 1965.
Who operates Ossauskoski?
Ossauskoski is operated by Kemijoki Oy.