Iwanuma Mill power station is a 165.8 MW coal power station in Miyagi Prefecture, Japan. It is operated by Nippon Paper Industries Co Ltd [100%]. Based on its capacity (estimated), it can supply roughly 207k homes (estimated). It ranks #208 of 692 Japan power plants by installed capacity. Commissioned in 1969, it is around 57 years old — an older, legacy facility. 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 GEM_coa_iwanumamill_japan.
Data status
Known data
Calculated from dataset
Not available
Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.
Capacity provenance
The public capacity above is the current source-record value. A 2026 tracker candidate lists 111 MW for Iwanuma Mill power station, but it is not used as the public primary value until scope is verified (unit vs operating vs installed/project total).
Data provenance
Capacity and fuel are the upstream open-dataset record, not yet matched to a 2026 registry or GEM entry.
capacity: GEM GCPT; fuel: GEM GCPT
In context: how this plant compares
At 165.8 MW, Iwanuma Mill power station is below 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.
Key facts
- Share of Japan coal capacity
- 0.3% of 53,431 MW across 94 plants in this dataset
- Age among peers
- 4 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 Nippon Paper Industries Co Ltd [100%].
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 38.1°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 0% 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: 50/100 — 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 corrosive environment (estimated ISO 9223 class C4 — High), 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 #53 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
- Iwanuma - Marubeni Solar Power Plant · Solar · 28.3 MW · Miyagi
- Nebio Kakuda power station · Other · 42.9 MW · Miyagi
- Sendai Takamatsu power station · Coal · 112 MW · Miyagi Prefecture
- Sendai Gamo power station · Biomass · 75 MW · Miyagi
- Kansai Sendai power station · Coal · 112 MW · Miyagi
- Soma Kyodo power station · Coal · 1,000 MW · Fukushima Prefecture
Location
Coordinates 38.0897829, 140.8607769 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
Frequently asked questions
What type of power plant is Iwanuma Mill power station?
Iwanuma Mill power station is a 165.8 MW coal power plant in Miyagi Prefecture, Japan, commissioned in 1969.
Who operates Iwanuma Mill power station?
Iwanuma Mill power station is operated by Nippon Paper Industries Co Ltd [100%].