Hydropower, or hydroelectricity, 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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Key findings

Hydropower generation in the Net Zero Scenario, 2010-2030


Due to droughts, hydropower generation decreased in 2021 for the first time in two decades, despite relatively high capacity growth

In 2021 global hydropower generation decreased by 15 TWh (down 0.4%) to 4 327 TWh. The drop in generation was caused by persistent droughts in hydropower-rich countries. At the same time, capacity additions in 2021 reached 35 GW, 50% higher than the average of the previous five years. However, severe draughts continue in 2022, which can result in continuation of below average generation.

In the Net Zero Emissions by 2050 Scenario, hydropower maintains an average annual generation growth rate of about 3% in 2022-2030 to provide approximately 5 700 TWh of electricity per year. In the last five years the growth rate was just one-third of what is required, signalling a need for significantly stronger efforts, especially to streamline permitting and ensure project sustainability.

Global net hydropower capacity additions by region, 1991-2030


Without 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.

Share of cumulative power capacity by technology, 2010-2027


Solar PV claims the most installed power capacity worldwide by 2027, surpassing coal, natural gas and hydropower

Cumulative PV capacity almost triples to over 2 350 GW by 2027 in the main case, surpassing hydropower in 2024, natural gas in 2026 and coal in 2027 to become the largest installed electricity capacity worldwide. Hydropower is falling to third place in terms of installed renewable capacity due to the rapid expansion of wind.

Overall renewable electricity generation is expected to increase almost 60% to reach over 12 400 TWh, with hydropower remaining the primary source of renewable electricity generation throughout the forecast period even though its capacity expands less than that of wind and solar PV.
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.