The year of the ‘water battery’ - global pumped storage capacity surpasses 200 GW

A total of 28 GW of hydropower capacity was commissioned in 2025, including a record 11.7 GW of pumped storage

• Global pumped storage capacity has now surpassed 200 GW, with a further 243 GW currently under construction worldwide.

• Hydropower is moving to the centre of energy security strategies worldwide, as governments prioritise 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.

The 2026 World Hydropower Outlook, released today by the International Hydropower Association (IHA), highlights hydropower’s rapidly evolving role in the global energy transition, as countries increasingly turn to flexible renewable generation and long-duration energy storage to support energy security, economic resilience and decarbonisation.

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 11.6 GW of pumped storage. Pumped storage capacity surpassed 200 GW globally for the first time, reinforcing its growing importance as the world’s dominant form of large-scale energy storage.

While conventional hydropower remains essential for low-carbon electricity generation, increasing shares of wind and solar power are driving growing demand for flexibility, balancing services and long-duration energy storage. As a result, pumped storage is becoming a strategic priority in major electricity markets worldwide.

China remained the dominant force in global hydropower development in 2025, accounting for more than 40% of worldwide hydropower capacity additions. The country now has more than 300 GW of hydropower under construction, including 218 GW of pumped storage.

Construction officially began in 2025 on the Yarlung Zangbo River Hydropower Project, projected to become the world’s largest hydropower facility and capable of generating roughly three times as much electricity as the Three Gorges Dam. While China’s new capacity additions remain substantial, its clean energy transition is increasingly shifting towards strengthening grid flexibility and hydro-wind-solar integration, elevating hydropower’s strategic role in system reliability and balancing.

Across South and Central Asia, hydropower growth is accelerating, supported by a regional development pipeline exceeding 300 GW. India is emerging as a global leader in pumped storage hydropower development, with plans to increase capacity from around 3.5–5 GW today to as much as 100 GW by 2035. Governments across the region are also strengthening cross-border cooperation on water management and electricity trade as climate pressures intensify.

In Europe, record levels of renewable energy curtailment and wider electricity system stress are accelerating demand for pumped storage and long-duration energy storage. Countries including the Netherlands, Germany, Spain, Belgium, Sweden and France recorded more than 500 hours of negative electricity pricing during 2025, highlighting growing flexibility shortages in increasingly renewable-heavy electricity systems. The European Union and national governments are responding through new market reforms, permitting measures and revenue stabilisation mechanisms designed to unlock major pumped storage investment pipelines.

Africa remained one of the strongest regions globally for new conventional hydropower additions for a second consecutive year, commissioning more than 4 GW in 2025. Landmark projects including Ethiopia’s Grand Ethiopian Renaissance Dam and Tanzania’s Julius Nyerere Hydropower Project significantly expanded electricity generation capacity while strengthening regional power systems and energy access. Transmission infrastructure and cross-border electricity trade are becoming increasingly important to unlocking the continent’s vast untapped hydropower potential.

Conventional hydropower deployment is also regaining momentum in South America, supported by a regional development pipeline of around 70 GW. Countries across the region are increasingly recognising hydropower not only as baseload generation but as a strategic flexibility asset capable of balancing rapidly expanding wind and solar fleets. Modernisation and digitalisation of ageing infrastructure are becoming central priorities, with more than half of South America’s hydropower fleet now over 30 years old.

In North and Central America, hydropower continues to serve as a backbone of electricity supply while governments increasingly focus on modernisation, life-extension and pumped storage development. Canada fully commissioned the 1.1 GW Site C project in British Columbia during 2025, while the United States advanced major permitting reforms and fast-track measures to support hydropower modernisation and new electricity infrastructure. More than 60 GW of pumped storage projects are now in development across the USA.

The report also identifies growing demand from data centres and digital infrastructure as a major emerging driver for hydropower worldwide. In North America, technology companies including Google and Microsoft signed landmark long-term hydropower supply agreements during 2025, reflecting rising demand for firm, carbon-free electricity capable of supporting rapidly expanding digital infrastructure and artificial intelligence growth.

Despite strong momentum globally, the Outlook warns that significant barriers continue to slow hydropower deployment in many markets. Financing constraints, permitting delays, transmission bottlenecks, climate-related hydrological variability and regulatory uncertainty remain major obstacles to both conventional hydropower and pumped storage development.

Climate change is also reshaping hydropower planning and operations worldwide. Severe droughts in parts of South America, South and Central Asia and Europe during 2025 exposed vulnerabilities linked to water availability and ageing infrastructure, while extreme weather events highlighted the importance of resilient and flexible electricity systems capable of responding to growing climatic volatility.

At the same time, the report finds that governments are increasingly recognising hydropower as strategic infrastructure capable of strengthening energy independence, supporting industrial growth and reducing exposure to imported fossil fuel price volatility.

Malcolm Turnbull, International Hydropower Association President, commented: As electricity systems become more dependent on variable renewables, and geopolitical tensions make reliance on imports more challenging, countries are increasingly recognising 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 – Co-Head of Power and Renewables, Addleshaw Goddard, commented: “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.”

Eddie Rich, CEO at the International Hydropower Association, said: "This year's Outlook tells a clear story. Pumped storage will double globally in 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."

Global hydropower in numbers:

• Global hydropower generation: 4,495 TWh

• Total installed hydropower capacity: 1,469 GW

• Capacity added in 2025: 28 GW

• Total pumped storage installed capacity: 201 GW

• Pumped storage capacity added in 2025: 11.7 GW

• Global hydropower development pipeline: 1,127 GW

• Global pumped storage development pipeline: 621 GW