Niihama Nishi power station is a 300 MW coal power station in Ehime, Japan. It is operated by Sumitomo Joint Electric Power Co. Based on its capacity (estimated), it can supply roughly 375k homes (estimated). It ranks #173 of 692 Japan power plants by installed capacity. Commissioned in 1984, it is around 42 years old — long-established. Its modelled annual emissions are 1,667,700 t CO₂/yr (Climate TRACE), equivalent to about 389k cars driven for a year. In context, coal supplies about 32.1% 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 WRI1020043.
Data status
Known data
Modelled source data
Calculated from dataset
Not available
Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.
Data provenance
Source of the capacity and fuel values:
capacity: GEM · 2026 · L100000102953; fuel: WRI GPPD
In context: how this plant compares
At 300 MW, Niihama Nishi power station is well above the median coal plant in Japan (250 MW). Technically it is described as subcritical. Coal plants burn pulverised coal to raise high-pressure steam for a turbine; they run as baseload but are the most carbon-intensive mainstream source and the first targeted for retirement or efficiency retrofits.
Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.
~1,667,700 t CO₂/yr (modelled) — in everyday terms
This facility's annual emissions are roughly equivalent to:
Equivalencies via US EPA Greenhouse Gas Equivalencies; modelled emissions from Climate TRACE.
Key facts
- Share of Japan coal capacity
- 0.6% of 53,431 MW across 94 plants in this dataset
- Age among peers
- 14 of 83 dated coal plants in Japan are older
Calculated from the capacity and generation records in this dataset (WRI Global Power Plant Database (CC BY 4.0)).
Capacity vs largest coal plants in Japan
Installed capacity (MW), WRI Global Power Plant Database (CC BY 4.0).
Owner
Operated by Sumitomo Joint Electric Power Co.
Local climate & thermal context
This coal plant burns coal to raise high-pressure steam that spins a turbine-generator. It sits in a humid subtropical climate (Köppen Cfa) — Northern Hemisphere, latitude 34.0°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 16% 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: 44/100 — this site sits in the mid 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 moderately corrosive environment (estimated ISO 9223 class C3 — Medium), 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 #42 largest coal power plant of 94 in Japan by capacity.
Japan has 94 coal power plants in this dataset, together about 53,431 MW of capacity.
Nearby power plants
- Niihama Kita thermal power station · Gas · 150 MW · Ehime
- Funayaotsu · Solar · 14 MW · Ehime
- Saijo power station · Coal · 406 MW · Ehime
- Saijo - Sumitomo Solar Power Plant · Solar · 23 MW · Ehime
- Nyugawa power station · Coal · 250 MW · Ehime
- Saijo - Itochu Solar Power Plant · Solar · 33.8 MW · Ehime
Location
Coordinates 33.9545, 133.2491 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
Frequently asked questions
What type of power plant is Niihama Nishi power station?
Niihama Nishi power station is a 300 MW coal power plant in Ehime, Japan, commissioned in 1984.
Who operates Niihama Nishi power station?
Niihama Nishi power station is operated by Sumitomo Joint Electric Power Co.
How much CO₂ does Niihama Nishi power station emit?
Niihama Nishi power station has modelled emissions of about 1,667,700 tonnes of CO₂ per year (Climate TRACE).