Nesjavellir is a 120 MW geothermal power station in South, Iceland. It is operated by Orkuveita Reykjavíkur. Based on its capacity (estimated), it can supply roughly 225,257 homes (estimated). It ranks #7 of 20 Iceland power plants by installed capacity. Commissioned in 1998, it is around 28 years old — long-established. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, geothermal supplies about 29.2% of Iceland's electricity; the national grid averages 28 gCO₂/kWh (100.0% low-carbon) (2024).
Plant data: WRI Global Power Plant Database (CC BY 4.0), id WRI1002805.
Installed capacity (MW), WRI Global Power Plant Database (CC BY 4.0).
Operated by Orkuveita Reykjavíkur. All plants by this company →
This geothermal plant taps underground heat to raise steam that drives a turbine. It sits in a polar tundra climate (Köppen ET) — Northern Hemisphere, latitude 64.1°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 122% 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: 96/100 — 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 #2 largest geothermal power plant of 6 in Iceland by capacity.
Iceland has 6 geothermal power plants in this dataset, together about 572 MW of capacity.
Coordinates 64.1081, -21.2567 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
