Siso is a 180 MW hydro power station in Nordland, Norway. It is operated by Siso Energi AS [100%]. Based on its capacity (estimated), it can supply roughly 180k homes (estimated). It ranks #51 of 307 Norway power plants by installed capacity. Commissioned in 1968, it is around 58 years old — an older, legacy facility. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, hydro supplies about 90.0% of Norway's electricity; the national grid averages 28 gCO₂/kWh (99.0% low-carbon) (2025).
Plant data: WRI Global Power Plant Database (CC BY 4.0), id WRI1003483.
Data status
Known data
Calculated from dataset
Not available
Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.
Capacity provenance
The public capacity above is the current source-record value. A 2026 tracker candidate lists 180 MW for Siso hydroelectric plant, but it is not used as the public primary value until scope is verified (unit vs operating vs installed/project total).
Data provenance
Source of the capacity and fuel values:
capacity: GEM · 2026 · L100000602966; fuel: WRI GPPD
In context: how this plant compares
At 180 MW, Siso is well above the median hydro plant in Norway (43 MW). Technically it is described as conventional storage. 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 Norway hydro capacity
- 0.6% of 28,510 MW across 291 plants in this dataset
- Age among peers
- 64 of 169 dated hydro plants in Norway 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 Norway
Installed capacity (MW), WRI Global Power Plant Database (CC BY 4.0).
Owner
Operated by Siso Energi AS [100%].
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 67.3°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 163% 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 mild atmospheric environment (estimated ISO 9223 class C2 — Low), 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 #46 largest hydro power plant of 291 in Norway by capacity.
Norway has 291 hydro power plants in this dataset, together about 28,510 MW of capacity.
Nearby power plants
Location
Coordinates 67.325, 15.7073 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
Frequently asked questions
What type of power plant is Siso?
Siso is a 180 MW hydro power plant in Nordland, Norway, commissioned in 1968.
Who operates Siso?
Siso is operated by Siso Energi AS [100%].