The International Hydropower Association (IHA) said global installed hydropower capacity reached 1,469 GW in 2025 after the addition of 28 GW of new capacity during the year, including a record 11.7 GW of pumped storage. Pumped storage capacity surpassed 200 GW globally for the first time, which the agency said reinforces the technology’s “growing importance as the world’s dominant form of large-scale energy storage.”
The IHA in its 2026 World Hydropower Outlook released June 23 highlighted what it called “hydropower’s rapidly evolving role in the global energy transition.” The group said hydropower is increasing in importance as countries “increasingly turn to flexible renewable generation and long-duration energy storage to support energy security, economic resilience and decarbonization.”
Malcolm Turnbull, president of the IHA, said, “As electricity systems become more dependent on variable renewables, and geopolitical tensions make reliance on imports more challenging, countries are increasingly recognizing the importance of flexibility, long-duration storage and resilient domestic generation. Hydropower and pumped storage are uniquely positioned to provide these services at scale.”
Rory Connor, partner and co-head of Power and Renewables for Addleshaw Goddard, a London, UK-headquartered law firm, said, “Hydropower is central to global energy security, stability and the energy transition. IHA’s World Hydropower Outlook is always a seminal report valued by the hydropower and wider energy industry year after year. We are delighted to help IHA launch the World Hydropower Outlook 2026.”
The 2026 World Hydropower Outlook is being discussed during the ongoing London Climate Action Week in the UK, happening now through June 28. The global event is hosted by Addleshaw Goddard in partnership with IHA, the Global Renewables Alliance, and the British Hydropower Association.
The report said that while conventional hydropower remains important for low-carbon electricity generation, the increasing share of solar and wind power on global power grids is driving calls for flexibility, balancing services, and long-duration energy storage. The group said that has led to pumped storage “becoming a strategic priority in major electricity markets worldwide.”
Highlights from the report include:
- Global pumped storage capacity has now surpassed 200 GW, with a further 243 GW currently under construction worldwide.
- Hydropower is moving to the center of energy security strategies worldwide, as governments prioritize system resilience, grid stability, and domestic electricity generation.
- Global hydropower capacity reached 1,469 GW by the end of 2025, remaining the world’s largest source of renewable electricity.
- The total global hydropower development pipeline now stands at 1,127 GW, including 621 GW of pumped storage projects across all stages of development.
- Rising electricity demand from digital infrastructure like data centres, electrification and industrial growth is strengthening demand for firm, renewable power.
Eddie Rich, CEO of IHA, told POWER, “2025 will be remembered as the year the water battery came of age. With global pumped storage capacity now exceeding 200 GW and more projects under construction than ever before, governments are increasingly recognizing that energy security, grid reliability and clean growth depend on long-duration storage. Hydropower provides the flexibility and resilience needed to power economies, integrate renewables and meet rising demand from industries, data centres and electrification.
“This year’s Outlook tells a clear story,” said Rich. “Pumped storage will double globally in [the] next 15 years. But we can and must go further. If the right policy changes are made, it should triple and if governments treat water batteries and chemical batteries equally, the industry will quadruple capacity by 2040.”
China Leads Hydro Additions
The IHA said the China, the global leader in renewable energy, accounted for more than 40% of worldwide hydropower capacity additions last year. The country now has more than 300 GW of hydropower under construction, including 218 GW of pumped storage.
China officially began construction last year of the $170-billion Yarlung Zangbo River Hydropower Project in Tibet, also known as the Motuo (or Medog) Hydropower Station. The project, being designed with five power stations with a total 60 GW of generation capacity, would be the world’s largest hydropower facility. It would be capable of generating about three times as much electricity as the current largest hydro project, the 22.5-GW Three Gorges Dam, according to the Chinese government. The IHA noted that China “is increasingly shifting towards strengthening grid flexibility and hydro-wind-solar integration, elevating hydropower’s strategic role in system reliability and balancing.”