OverWatts Atlas Live map
Browse the atlas

Japan · asset class

Power Plants in Japan

Japan has 387 power plants mapped on the OverWatts open energy atlas — the 11th-largest fleet of the 155 countries that hold any, and 1% of the world's mapped total. Of these, 248 operating and 88 under construction or proposed. Operating generation capacity totals 199 GW across 248 utility-scale plants of 100 MW and above. The largest is Kashiwazaki Kariwa nuclear power plant (5.5 GW).

The largest owner-operators are JERA Co Inc (38), Kansai Electric Power Co (35) and Tohoku Electric Power Co Inc (18) — JERA Co Inc alone is named on 10% of them. Half of Japan's power plants in service predate 1991 (median commissioning year of the 246 with a known date), 42 came online in the past decade and the oldest still listed is Yomikaki hydroelectric plant, dating from 1923. 88 are in the pipeline, led by SSE Pacifico Prospective Japanese Projects wind farm (4.1 GW), proposed. They account for 56% of every energy asset OverWatts maps in Japan.

See them on the map →Power Plants worldwide →
387
Power Plant in Japan
#11
of 155 countries
199 GW
Operating capacity
88
In construction / proposed

Operating generation capacity by fuel

On the interactive map

Open the interactive map →

Largest power plants in Japan

Who owns Japan's power plants

Counts an asset once per company named as its owner or operator; a joint venture counts for each partner.

When they were built

Median commissioning year 1991 · oldest Yomikaki hydroelectric plant (1923) · newest Amaterasu Shiraishi solar farm (2025) · 246 of 387 carry a start date

Under construction & proposed

How Japan compares · power plants by country

Frequently asked

How many power plants are there in Japan?
OverWatts maps 387 power plants in Japan — 1% of the world's mapped total, the 11th-largest national fleet of the 155 countries with any.
What is the largest power plant in Japan?
Kashiwazaki Kariwa nuclear power plant, at 5.5 GW, operated by Tokyo Electric Power.
How much power-generation capacity do Japan's power plants have?
About 199 GW operating across 248 plants, with a further 131 GW under construction or proposed. That covers utility-scale sites of 100 MW and above, so it sits below national installed capacity wherever distributed generation is large.
Who owns the power plants in Japan?
JERA Co Inc is named as owner or operator on the most — 38 of 387 (10%). Next are Kansai Electric Power Co (35), Tohoku Electric Power Co Inc (18) and Kyushu Electric Power Co Inc (17).
How old are Japan's power plants?
The median commissioning year is 1991, across the 246 in service with a known start date. The oldest still listed is Yomikaki hydroelectric plant (1923); 42 came online in the past ten years.
What new power plants are being built in Japan?
88 projects are under construction or proposed. The largest are SSE Pacifico Prospective Japanese Projects wind farm (4.1 GW), Ishikari Bay offshore wind farm (3.0 GW) and Kashiwazaki Kariwa nuclear power plant (2.7 GW).

Other asset classes in Japan

Pipeline 93LNG Terminal 57Iron & Steel Plant 42Grid Storage 35Cement Plant 31Chemical Plant 17Refinery 10Export Terminal 8Interconnector 6Data Centre 2Oil / Commodity Contract 1Storage / Tank Farm 1

Power Plants in other countries

China 11,537United States 3,831India 1,675Brazil 879Spain 653Australia 615Philippines 489Russia 461Canada 452Vietnam 392Germany 335Mexico 311