Hydropower
Hydropower is expected to remain the world’s largest source of renewable electricity generation and play a critical role in decarbonising the power system and improving system flexibility.
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Hydropower is a mature technology, yet it continues to evolve. Reservoir hydropower plants and pumped storage plants are particularly suited to providing system flexibility, while run-of-the river hydropower plants are themselves variable according to current or seasonal weather conditions.
Run-of-river hydropower plants harness energy for electricity production mainly from the available flow of the river. These plants may include short-term storage or "pondage", allowing for some hourly or daily flexibility but they usually have substantial seasonal and yearly variations.
Reservoir hydropower plants rely on stored water in a reservoir. This provides the flexibility to generate electricity on demand and reduces dependence on the variability of inflows. Very large reservoirs can retain months or even years of average inflows and can also provide flood protection and irrigation services.
Pumped storage plants use water that is pumped from a lower reservoir into an upper reservoir when electricity supply exceeds demand or can be generated at low cost. When demand exceeds instantaneous electricity generation and electricity has a high value, water is released to flow back from the upper reservoir through turbines to generate electricity. Pumped storage currently represents the overwhelming majority of on-grid electricity storage.
Run-of-river hydropower plants harness energy for electricity production mainly from the available flow of the river. These plants may include short-term storage or "pondage", allowing for some hourly or daily flexibility but they usually have substantial seasonal and yearly variations.
Reservoir hydropower plants rely on stored water in a reservoir. This provides the flexibility to generate electricity on demand and reduces dependence on the variability of inflows. Very large reservoirs can retain months or even years of average inflows and can also provide flood protection and irrigation services.
Pumped storage plants use water that is pumped from a lower reservoir into an upper reservoir when electricity supply exceeds demand or can be generated at low cost. When demand exceeds instantaneous electricity generation and electricity has a high value, water is released to flow back from the upper reservoir through turbines to generate electricity. Pumped storage currently represents the overwhelming majority of on-grid electricity storage.
Last updated Jan 7, 2022
Key findings
Hydropower and wind electricity generation growth in selected markets, 2015-2020 average and 2021
Open
Hydropower generation increased 124 TWh (+3%) in 2020, reaching 4 418 TWh and remaining the largest renewable source of electricity, generating more than all other renewable technologies combined. After five consecutive years of decline, hydropower capacity additions rebounded in 2020 and reached 21 GW thanks to commissioning of several large power plants in China and Turkey.
In 2021 however, severe drought conditions in Brazil, the United States, China and Turkey have limited global hydropower generation. As a result, our forecast expects hydropower generation to remain stable compared with 2020, ending the annual increases seen since 2001.
Hydropower generation in the Net Zero Scenario, 2000-2030
OpenHydropower is not fully on track with the Net Zero Scenario
In the Net Zero Emissions by 2050 Scenario, hydropower maintains a 3% average annual generation growth rate between 2020 and 2030 to provide 5 870 TWh of electricity per year. To meet this level, an average 48 GW of new capacity should be connected to the grid annually during this period. Although capacity additions are expected to accelerate in upcoming years owing to the many large projects under construction in China, India, Ethiopia and Southeast Asia, achieving the required deployment will take much more effort, especially to streamline permitting and ensure project sustainability.
Global net hydropower capacity additions by region, 1991-2030
OpenWithout major policy changes, global hydropower expansion is expected to slow down this decade
Global hydropower capacity is set to increase by 17%, or 230 GW, between 2021 and 2030. However, net capacity additions over this period are forecast to decrease by 23% compared with the previous decade. The contraction results from slowdowns in the development of projects in China, Latin America and Europe. However, increasing growth in Asia Pacific, Africa and the Middle East partly offsets these declines.
The IEA is providing the world’s first detailed forecasts to 2030 for three types of hydropower: reservoir, run-of-river and pumped storage plants. Reservoir hydropower plants account for half of net hydropower additions through 2030 in our forecast. Pumped storage hydropower plants represent 30% of net hydropower additions through 2030 in our forecast. Run-of-river hydropower remains the smallest growth segment because it includes many small-scale projects below 10 MW.
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Our work on Hydropower
Hydropwer is the largest source of renewable electricity in the world and it is particularly suited to providing system flexibility. The Hydropower TCP is a global platform for advancing hydropower technology, encouraging the sustainable use of water resources for the development and management of hydropower.
Related sectoral Technology Collaboration Programmes (TCP)
Events
25 Mar 2022 09:00—16:00
IEA Low-Carbon Gas Day
12 Oct 2021 11:30—13:45
Hydropower in India
20 Jul 2021 14:30—15:15
Hydropower Special Market Report Webinar
26 Mar 2021 14:00—15:30
