Does Japan Use Hydropower?
Hydropower is a form of renewable energy that harnesses the power of flowing water to generate electricity. It is one of the oldest and most widely used forms of renewable energy in the world. Hydropower uses the natural water cycle of evaporation and precipitation to move water. Typically, hydropower plants capture water from a river or stream and direct it through large pipes called penstocks. The moving water spins a turbine connected to a generator to produce electricity.
Hydropower provides a number of benefits such as being a clean energy source, reliable baseload power, energy storage capabilities, and recreational opportunities. Currently, hydropower accounts for 7% of total U.S. utility-scale electricity generation and makes up 37% of renewable electricity generation. With substantial hydropower resources still untapped, this resource has the potential to grow and continue meeting U.S. electricity demands.
Japan’s Energy Mix
Japan has a diverse energy mix for electricity generation. In 2021, the main sources were coal (31%), natural gas (37%), oil (3%), hydropower (8%), nuclear (6%), solar (7%), wind (1%), geothermal (1%) and other renewables (5%) according to the International Energy Agency (https://www.iea.org/countries/japan). Fossil fuels like coal, natural gas and oil made up the majority at 71% of the electricity generation mix. Renewables accounted for 22%, with hydropower being the largest renewable source. Nuclear power used to account for a larger share, but its contribution decreased after the 2011 Fukushima nuclear accident. Overall, Japan’s electricity generation mix has been shifting away from fossil fuels and nuclear towards an increasing share of renewables.
Hydropower in Japan
Japan has significant hydropower resources and a long history of hydroelectric development. As of 2021, hydropower accounted for approximately 8% of Japan’s total electricity generation capacity, with around 50,000 megawatts (MW) of installed capacity according to Statista.
While hydropower capacity has remained relatively stable in recent years, Japan tapped most of its viable large-scale hydropower resources in the 20th century. Currently, there are over 2,700 hydropower plants across Japan, mostly small-scale facilities under 1 MW. The smaller plants account for around 15% of Japan’s hydropower capacity. The remaining 85% comes from large and medium hydropower stations, especially in mountainous regions of Honshu and Kyushu.
Hydropower plays an important role in Japan’s energy mix and electricity generation. While growth potential is constrained compared to other renewables like solar and wind, existing hydropower helps provide stable baseload power and grid balancing services. Overall, Japan relies on hydropower as a domestic, renewable energy source that will continue contributing to energy security and sustainability objectives.
History of Hydropower in Japan
Hydropower has a long history in Japan, with the first hydropower plant being built in Kyoto in 1887 to provide electricity for lightbulbs and trains. Hydropower development expanded rapidly in the early 20th century to power Japan’s growing industrialization. According to a 2019 study, over 1,200 hydropower plants had been constructed in Japan by the end of World War II [1].
The growth of hydropower continued in the postwar period to meet electricity demand. Many large dams and pumped storage hydropower projects were constructed between the 1950s-1970s. Total hydropower capacity reached 27 GW by 1980, meeting around 27% of Japan’s electricity needs at the time [2]. While growth has slowed since then, Japan still taps a significant amount of hydropower, with around 8% of its electricity coming from hydropower today.
Potential for Growth
Japan’s conventional hydropower potential is considered to be almost fully utilized, with limited opportunities for major capacity expansion (https://en.wikipedia.org/wiki/Hydroelectricity_in_Japan). In 2022, Japan had around 50,000 MW of installed hydropower capacity (https://www.statista.com/statistics/1197639/japan-hydropower-generation-capacity/). However, some prefectures like Toyama have significant untapped small-scale hydropower resources that could still be developed.
The Japanese government has assessed the potential for growth in hydropower, especially micro and small hydropower projects under 1 MW capacity. Recent policy changes allow small power producers to sell excess electricity to utilities, creating more incentive for small hydropower development. Overall, Japan likely has an additional 1,500 MW of feasible small hydropower capacity that could be built in the coming years if supported by favorable policies.
While large-scale hydropower is limited by geographical constraints, targeted development of smaller projects and upgrades to existing infrastructure can still help Japan incrementally grow its hydropower capacity. However, growth is constrained compared to other renewable sources like solar and wind power which have greater remaining potential.
Benefits of Hydropower
Hydropower provides many benefits in addition to generating electricity. As a clean, renewable, and domestic source of energy, hydropower offers environmental and economic advantages over other sources of electricity. Hydroelectric power plants emit virtually no carbon dioxide and do not produce air pollution like fossil fuel plants. Compared to nuclear power and other renewables like solar and wind, hydropower facilities have a much longer lifespan and require less maintenance and upkeep over time. According to the U.S. Department of Energy, hydropower is “an affordable way to add clean, renewable electricity generation capacity to the nation’s grid” (https://www.energy.gov/eere/water/benefits-hydropower).
Hydropower is a flexible energy source that can easily adjust output to meet changing demands for electricity. The flow of water driving the turbines can be rapidly controlled, allowing hydropower to fill gaps when other sources fluctuate. This makes the overall power system more reliable. Hydropower plants also offer storage capabilities by pumping water uphill into reservoirs during low-demand periods, then releasing it to generate power when electricity use peaks. According to Enel Green Power, hydropower’s ability to stabilize the grid helps accommodate intermittent renewable resources like wind and solar (https://www.enelgreenpower.com/learning-hub/renewable-energies/hydroelectric-energy/advantages).
Challenges of Hydropower
Hydropower faces several key challenges despite its status as a mature renewable energy technology (Irena, 2023). Two major challenges include the high upfront costs and potential impacts on rivers and habitats.
Constructing hydropower plants requires substantial upfront investments, especially for large-scale projects like dams and reservoirs. The costs include land acquisition, infrastructure, turbines and other equipment. These high capital costs can deter investment and make financing difficult (DOI, 2022).
Hydropower projects also alter the natural flow of rivers which can negatively impact wildlife habitats and ecosystems. Dams obstruct fish migration routes and change water levels downstream. Reservoirs flood valleys and forests. Mitigation measures like fish ladders can help, but balancing power generation and environmental stewardship remains an ongoing challenge.
Comparison to Other Renewables
While hydropower plays an important role in Japan’s renewable energy portfolio, other sources like solar and wind have seen more significant growth in recent years. As of 2021, hydropower accounted for around 8.4% of Japan’s renewable energy generation, while solar made up 7.4% and wind 1.7% (source: https://eastasiaforum.org/2023/06/10/reaching-japans-resourceful-solar-and-wind-energy-future/).
Japan has strong potential for expanding both solar and wind power due to its geographical advantages. The country has abundant solar resources across most regions and favorable wind conditions along its coasts and mountain ridges (source: https://www.pv-magazine.com/2023/06/19/japans-vast-wind-and-solar-resources/). Studies show Japan could cost-effectively generate all of its electricity from wind and solar in the future.
Compared to hydropower which has limited potential for new projects, solar and wind are seen as greater growth opportunities in Japan’s renewable energy mix going forward. The government has set ambitious targets for installing more solar and wind capacity by 2030. While hydropower will continue playing a role, solar and wind are expected to make up a larger share of Japan’s renewable generation in the coming decades.
Future Outlook
Looking ahead, expectations for hydropower’s role in Japan’s energy mix are mixed. On one hand, the Japanese government has set ambitious renewable energy targets, aiming for hydropower to provide 9% of Japan’s electricity by 2030, up from around 8% today.1 To help achieve this, there are plans underway to build new pumped storage hydropower facilities as a form of energy storage.
However, challenges remain. Climate change is projected to lead to more severe droughts and floods in Japan, which could hamper hydropower output.2 Competition from other renewables like solar PV and wind power is also increasing. Costs for hydropower tend to be higher in Japan compared to other countries.3
While hydropower will likely continue playing an important role, its growth may be constrained unless new technologies and incentives can improve its cost-competitiveness. Striking a balance between hydropower, climate resilience, and river ecosystems will also be an ongoing challenge.
Conclusion
In summary, while hydropower accounts for a small portion of Japan’s overall energy mix at around 8%, it still plays an important role in the country’s renewable energy landscape. Hydropower has a long history in Japan dating back over 1,000 years, with the potential for further growth, especially through upgrading existing facilities. The main benefits of hydropower include its reliability, low operating costs, and lack of greenhouse gas emissions. However, challenges remain around environmental impacts and securing sites. Looking ahead, hydropower will likely maintain its place in Japan’s energy mix as the country continues to diversify its renewable sources and reduce reliance on imported fossil fuels.
To directly answer the original question, yes Japan does utilize hydropower as part of its overall energy production and expects hydropower generation capacity to remain stable going forward.
