Hamaoka is a 3,617 MW nuclear power station in Shizuoka, Japan. It is operated by Chubu. Based on its capacity (estimated), it can supply roughly 8,147,550 homes (estimated). It ranks #11 of 659 Japan power plants by installed capacity. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, nuclear supplies about 9.1% of Japan's electricity; the national grid averages 477 gCO₂/kWh (32.7% low-carbon) (2025).
Plant data: WRI Global Power Plant Database (CC BY 4.0), id WRI1000680.
Installed capacity (MW), WRI Global Power Plant Database (CC BY 4.0).
Operated by Chubu. All plants by this company →
This nuclear plant uses heat from nuclear fission to raise steam for a turbine-generator. It sits in a humid subtropical climate (Köppen Cfa) — Northern Hemisphere, latitude 34.6°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 41% below 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: 33/100 — this site sits in the bottom 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 #4 largest nuclear power plant of 16 in Japan by capacity.
Japan has 16 nuclear power plants in this dataset, together about 42,537 MW of capacity.
Coordinates 34.6235, 138.1421 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
