Hydroelectricity in Japan

Hydroelectricity is Japan’s main renewable energy source, with an installed capacity of about 50 GW (including pumped storage) and a production of 69.2 TWh of electricity in 2009, making Japan one of the biggest hydroelectricity producers in the world. Most of Japanese hydroelectric power plants are pumped-storage plants. Conventional hydropower plants account for about 20 GW out of the total installed capacity as of 2007.

Conventional hydropower potential of Japan is considered to be almost fully developed, with little opportunity for further capacity increase. In recent years, almost exclusively pumped storage plants were commissioned, significantly increasing the ratio of pumped storage capacity over conventional hydro. The large capacity of pumped storage hydropower was built to store energy from nuclear power plants, which until the Fukushima disaster constituted a large part of Japan electricity generation. As of 2015, Japan is the country with the highest capacity of pumped-storage hydroelectricity in the world, with 26 GW of power installed. After the 2011 nuclear power shutdowns, pumped-storage plants have been increasingly used to balance the variable generation of renewable energy sources such as solar, which have been growing rapidly in recent years.

As of September 2011, Japan had 1,198 small hydropower plants with a total capacity of 3,225 MW. The smaller plants accounted for 6.6% of Japan’s total hydropower capacity. The remaining capacity was filled by large and medium hydropower stations, typically sited at large dams. Cost per kilowatt-hour for power from smaller plants was high at ¥15-100, hindering further development of the energy source.

Hydroelectric potential
The technically exploitable hydroelectric potential of Japan is estimated in 2013 by the World Energy Council at 136.5 TWh/ year. Most sites favorable to the installation of large plants have been equipped; the major projects underway or planned are pumped storage plants. The technical potential of small hydro is estimated at 47 TWh/ year. At the end of 2011, the installed capacity of the small hydro was 3.5 GW. or 12.5% of the total conventional power.

The hydro power Japan is the main source of renewable energy in the country with a power generation 92.55 TWh in 2017, the 8 th world with 2.2% of world production; it provided 8.8% of Japan’s total electricity production in 2015.

The power hydroelectric plants in Japan reached 49,905 MW end 2017, the 5 th in the world with 3.9% of the world total.

The originality of Japan in this area is the preponderant share of power plants pumped: 27,637 MW at second in the world with 18.1% of the world total, behind China.

Hydroelectric Generation
Hydroelectric production in Japan reached 92.55 TWh in 2017, the 8 th world with 2.2% of world production, far behind China (28.5%) h.

In 2015, hydroelectric generation amounted to 91.27 TWh. representing 8.8% of the country’s electricity production and 52% of its renewable electricity production.

Installed power
The installed capacity of hydroelectric power plants in Japan reached 49,905 MW end 2017, the 5th in the world with 3.9% of the global total, far behind China (341,190 MW; 26.9%) and the USA (102 867 MW. 8.1%). More than half of that power is made up of central pumped: 27,637 MW at second in the world with 18.1% of the world total, behind China (19.6%) and ahead of the United States (14.9%) h.

In 2016, the Japanese Ministry of the Environment selected an international consortium to build its first commercial-scale (2 MW) tidal power plant in Naru Strait near Nagasaki.

In 2015, Toshiba installed the second 200 MW group of the Kyogoku pumping station in Hokkaido; the first turbine was commissioned in 2014. Both turbines use variable speed technology which allows the plant, while providing peak power, to suppress frequency fluctuations on the grid.

Hydropower plants accounted for 16% of the total installed capacity in 2011 with 48 GW. of which about half was pumped-storage; a group was commissioned at the Kannagawa plant in 2012, and an additional 3.3 GW will be commissioned by 2022.

Major hydroelectric plants
The article in English Hydroelectricity in Japan provides a list of dozens of Japanese hydropower plants; we can see that the 20 most powerful are pumped-storage plants; among the others, usually referred to as conventional power plants, the most powerful are:

Okutadami Dam, which supplies Japan’s most powerful conventional hydropower plant (560 MW).
Miyanaka Dam (449 MW)
Tagokura Dam (390 MW)
Kurobe Dam (336 MW)

Pumping and storage plants
The plants pumped up more than half of the hydroelectric power of Japan: 27,637 MW in 2017, second in the world with 18.1% of the world total, behind China (19.6%) and ahead of United States (14.9%) h.

Japan is particularly well equipped in pumped storage plants:
Japan is ranked 3 th in the world (behind China and the United States) for the number of plants pumped large (1000 MW and over): he has 7 plants with a total capacity of 9 293 MW, plus 2 plants under construction (4,420 MW). The most powerful of these plants, Okutataragi (1,932 MW), in Hyōgo Prefecture. was commissioned in 1974 and is owned by Kansai Electric Power Company. The central building Kannagawa. whose commissioning is scheduled for 2020, will be the 2 th most powerful in the world with 2820 MW. after that of Bath County in the United States; two of its six 470 MW units were commissioned in 2005 and 2012.

Japan has begun to equip plants pumped from 1930. Tokyo Electric Power Company (TEPCO) has 9 of these plants totaling approximately 10,000 MW. which Kannagawa plant under construction.

The Japan is the first country to build a plant pumped seawater (marine or STEP), on the island of Okinawa, 1999 with an average elevation of 136 meters and a capacity of 30 turbinable MW usable for 8 hours.

Small hydraulic
In September 2011, Japan had 1,198 small hydropower plants with a total capacity of 3,225 MW. These small plants accounted for 6.6% of Japan’s total installed hydro capacity. the rest corresponded to large and medium-sized plants, usually associated with large dams. The production cost per kilowatt hour of small plants was high: ¥ 15-100, preventing the development of this energy source.

Energy Policy
Japan has set a target of 9.6% of its electricity from hydropower by 2030.

Japan assures small hydro feed-in tariffs of 35.7 JPY/ kWh (0.29 €/ kWh over 20 years for a power less than 200 kW. 30.45/ JPY kWh from 200 kW to 1 MW and JPY 25.2/ kWh from 1 MW to 3 MW.

Source from Wikipedia