Hongawa is a 615 MW hydro power station in Ehime, Japan. It is operated by Shikoku. Based on its capacity (estimated), it can supply roughly 615,702 homes (estimated). It ranks #120 of 659 Japan power plants by installed capacity. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, hydro supplies about 7.2% 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 WRI1000718.
Installed capacity (MW), WRI Global Power Plant Database (CC BY 4.0).
Operated by Shikoku. All plants by this company →
This hydro plant converts the energy of falling or flowing water through hydro turbines. It sits in a humid subtropical climate (Köppen Cfa) — Northern Hemisphere, latitude 33.8°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 7% 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: 53/100 — this site sits in the mid 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 #19 largest hydro power plant of 55 in Japan by capacity.
Japan has 55 hydro power plants in this dataset, together about 27,439 MW of capacity.
Coordinates 33.7657, 133.3411 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
