Home / Asia / Japan / Joetsu Solar Power Plant

Joetsu Solar Power Plant

Solar power plant in Niigata, Japan. Approximate location 37.2117, 138.3126.

SolarNiigataJapan

Joetsu Solar Power Plant is a 2 MW solar power plant in Niigata, Japan. It is operated by Inpex Mega Solar Joetsu. Based on its capacity (estimated), it can supply roughly 850 homes (estimated). It ranks #670 of 692 Japan power plants by installed capacity. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, solar supplies about 9.8% of Japan's electricity; the national grid averages 477 gCO₂/kWh (32.7% low-carbon) (2025).

2Source-backed capacity
850homes powered (est.)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id WRI1026489.

Data status

Known data

FacilityJoetsu Solar Power Plant WRI
CountryJapan · Niigata WRI
Coordinates37.2117, 138.3126 WRI
FuelSolar WRI
MW installed capacity2 MW WRI source record; scope not independently normalised
OwnerInpex Mega Solar Joetsu WRI

Calculated from dataset

Capacity rank in country#670 of 692 calculated
Fuel-specific rank in country#302 of 324 calculated
Capacity vs country/fuel peers0.15× · 13 MW median · 324 peers calculated
Homes-powered equivalent850 calculated
Climate11.4°C · HDD 2,838 derived from coordinates
Environmental severityC4 · 43/100 derived from coordinates

Not available

CommissionedNot available not in dataset
TechnologyNot available not in dataset
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 L100001036076); fuel: WRI source-record fuel

In context: how this plant compares

At 2 MW, Joetsu Solar Power Plant is below the median solar plant in Japan (13 MW). Solar PV converts sunlight directly into electricity with no moving parts or fuel; output varies by time of day and weather, so it pairs with storage or flexible backup.

Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.

Capacity vs largest solar plants in Japan

Setouchi: 235 MW235SetouchiTomatoh Abira Solar Power Plant: 111 MW111Tomatoh Ab…Hosoe: 96 MW96HosoeOita - Marubeni Solar Power Plant: 82 MW82Oita - Mar…Kagoshima - Nanatsujima Solar Power Plant: 70 MW70Kagoshima …Rokkasho - Takahoko Solar Power Plant: 65 MW65Rokkasho -…Minamisoma: 60 MW60MinamisomaShin Mine CS: 56 MW56Shin Mine …

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

Owner

Operated by Inpex Mega Solar Joetsu.

Local climate & thermal context

This solar plant converts sunlight directly into electricity with photovoltaic panels. It sits in a humid subtropical climate (Köppen Cfa) — Northern Hemisphere, latitude 37.2°N — which shapes how much energy it can produce and how its output varies through the year.

11.4°Cannual mean temp
2,838heating degree-days (base 18°C)
451cooling degree-days (base 18°C)
320 melevation

Monthly mean temperature

J: 0 °CJF: 0 °CFM: 2 °CMA: 9 °CAM: 15 °CMJ: 19 °CJJ: 23 °CJA: 24 °CAS: 20 °CSO: 14 °CON: 8 °CND: 3 °CD24 °C

Heating degree-days here run 15% 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: 58/100 — this site sits in the mid third of the power plants we cover by heating degree-days.

Solar PV loses ~0.35%/°C above 25°C cell temperature — roughly 0.0% at warm-season highs here (estimate).

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 corrosive environment (estimated ISO 9223 class C4 — High), with humidity / wetness the leading environmental stress.

C4ISO 9223 corrosivity (indicative)
43/100environmental-severity index
25.0°Cseasonal temperature swing
50 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 #302 largest solar power plant of 324 in Japan by capacity.

Japan has 324 solar power plants in this dataset, together about 5,680 MW of capacity.

Nearby power plants

Location

Coordinates 37.2117, 138.3126 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions

What type of power plant is Joetsu Solar Power Plant?

Joetsu Solar Power Plant is a 2 MW source-record solar power plant in Niigata, Japan.

How many homes can Joetsu Solar Power Plant power?

Its output is enough to supply roughly 850 homes (estimated).

Who operates Joetsu Solar Power Plant?

Joetsu Solar Power Plant is operated by Inpex Mega Solar Joetsu.

Built from open public data; no personal information. Operate this site? Request a correction or removal.