The World Hydropower Outlook, a flagship annual publication by IHA, tracks and directs the progress of hydropower development globally against net zero pathways. Drawing upon exclusive new development insights from IHA’s global database, it provides in-depth analysis of hydropower’s evolving role in the energy transition.
As electricity demand grows and power systems become increasingly dependent on variable renewables, hydropower is moving to the centre of energy security strategies worldwide. The report highlights how flexible hydropower and pumped storage are becoming essential for grid stability, resilience and long-duration energy storage, whilst examining the policy, financing and infrastructure challenges that continue to shape global deployment.
The year of the water battery
Global hydropower capacity grew by 28 GW in 2025, including a record 11.7 GW of pumped storage. Pumped storage capacity surpassed 200 GW worldwide for the first time, cementing its position as the world's largest form of energy storage.
Pipeline reaches new heights
The global hydropower development pipeline now stands at 1,127 GW, including 621 GW of pumped storage projects across all stages of development. A further 243 GW of pumped storage is already under construction, reflecting growing demand for flexibility and long-duration storage.
Hydropower powers energy security
Governments are increasingly recognising hydropower as strategic infrastructure that strengthens energy independence, supports industrial growth and improves grid resilience. Rising electricity demand from electrification, industry, artificial intelligence and data centres is accelerating demand for firm, renewable power.
China drives global development
China remained the world's largest hydropower market in 2025, accounting for more than 40% of global capacity additions. The country has more than 300 GW of hydropower under construction, including 218 GW of pumped storage, as it accelerates hydro-wind-solar integration and grid flexibility.
Regional momentum builds
South and Central Asia's development pipeline now exceeds 300 GW, led by rapid pumped storage growth in India. Africa delivered more than 4 GW of new conventional hydropower for a second consecutive year, while Europe is expanding pumped storage investment to address growing flexibility shortages in renewable-heavy power systems.
