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Nokanan

Hydro power plant in Hokkaido, Japan. Approximate location 43.4879, 142.2196.

HydroHokkaidoJapanconventional storage

Nokanan is a 30 MW hydro power plant in Hokkaido, Japan. It is operated by HOKKAIDO ELECTRIC POWER CO INC. Based on its capacity (estimated), it can supply roughly 30k homes (estimated). It ranks #386 of 692 Japan power plants by installed capacity. Commissioned in 1971, it is around 55 years old — an older, legacy facility. 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).

30Source-backed capacity
30,034homes powered (est.)
1971commissioned (~55 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id WRI1020227.

Data status

Known data

FacilityNokanan WRI
CountryJapan · Hokkaido WRI
Coordinates43.4879, 142.2196 WRI
FuelHydro WRI
MW installed capacity30 MW WRI source record; scope not independently normalised
OwnerHOKKAIDO ELECTRIC POWER CO INC WRI
Commissioned1971 WRI
Technologyconventional storage WRI

Calculated from dataset

Capacity rank in country#386 of 692 calculated
Fuel-specific rank in country#55 of 55 calculated
Capacity vs country/fuel peers0.09× · 350 MW median · 55 peers calculated
Homes-powered equivalent30,034 calculated
Climate5.2°C · HDD 4,697 derived from coordinates
Environmental severityC2 · 33/100 derived from coordinates

Not available

GWh reported / yrNot available not in dataset
CO₂ emissionsnot applicable not applicable

Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.

Data provenance

The capacity and/or fuel fields on this page include a source-backed provenance label from GEM, an official registry, Wikidata, OSM, or a cross-source match.

capacity: GEM tracker 2026 (location L100001054754); fuel: WRI source-record fuel

In context: how this plant compares

At 30 MW, Nokanan is below the median hydro plant in Japan (350 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.

Capacity vs largest hydro plants in Japan

Okutataragi: 1,932 MW2kOkutataragiOkumino: 1,500 MW2kOkuminoOkawachi: 1,280 MW1kOkawachiShin Takasegawa: 1,280 MW1kShin Takas…Okuyoshino: 1,206 MW1kOkuyoshinoMatanogawa: 1,200 MW1kMatanogawaOmarugawa: 1,200 MW1kOmarugawaTamahara: 1,200 MW1kTamahara

Installed capacity (MW), WRI Global Power Plant Database (CC BY 4.0).

Owner

Operated by HOKKAIDO ELECTRIC POWER CO INC. 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 warm-summer humid continental climate (Köppen Dfb) — Northern Hemisphere, latitude 43.5°N — which shapes how much energy it can produce and how its output varies through the year.

5.2°Cannual mean temp
4,697heating degree-days (base 18°C)
41cooling degree-days (base 18°C)
382 melevation

Monthly mean temperature

J: -8 °CJF: -8 °CFM: -4 °CMA: 3 °CAM: 9 °CMJ: 14 °CJJ: 18 °CJA: 19 °CAS: 14 °CSO: 8 °CON: 1 °CND: -5 °CD19 °C

Heating degree-days here run 91% 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: 92/100 — 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

For a plant’s outdoor hardware — heat-recovery steam generators (HRSG), expansion joints, valves, flanges and their insulation — the local climate sets how fast unprotected steel and coatings degrade. This site sits in a mild atmospheric environment (estimated ISO 9223 class C2 — Low), with thermal cycling the leading environmental stress.

C2ISO 9223 corrosivity (indicative)
33/100environmental-severity index
27.3°Cseasonal temperature swing
60 kmdistance to coast

Higher environmental severity is exactly where protective removable insulation pays back most: a sheltered micro-climate slows corrosion, UV and thermal-cycling damage and extends outdoor hardware service life. This is an indicative site-climate context — not a condition assessment of any specific plant or operator.

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 #55 largest hydro power plant of 55 in Japan by capacity.

Japan has 55 hydro power plants in this dataset, together about 27,749 MW of capacity.

Nearby power plants

Location

Coordinates 43.4879, 142.2196 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions

What type of power plant is Nokanan?

Nokanan is a 30 MW source-record hydro power plant in Hokkaido, Japan, commissioned in 1971.

How many homes can Nokanan power?

Its output is enough to supply roughly 30,034 homes (estimated).

Who operates Nokanan?

Nokanan is operated by HOKKAIDO ELECTRIC POWER CO INC.

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