Hydropower is the electrical energy derived from turbines being driven by flowing water in rivers, with or without man-made dams forming reservoirs.
Presently, hydropower is the world’s largest source of renewable electricity. China is the leading hydropower producer, followed by Brazil, Canada, the United States, and Russia. Hydropower represents the largest share of renewable electricity production. It was second only to wind power for new-built capacities between 2005 and 2010.
The IEA’s Energy Technology Perspectives 2010 BLUE map scenario – which sets the goal of halving global energy-related CO2 emissions by 2050 (compared to 2005 levels) – projects that hydro could produce up to 6,000 terawatt-hours in 2050, roughly twice as much as today.
Hydropower’s storage capacity and fast response characteristics are especially valuable to meet sudden fluctuations in electricity demand and to match supply from less flexible electricity sources and variable renewable sources, such as solar PV and wind power.
The environmental and social effects of hydropower projects need to be carefully considered. Countries should follow an integrated approach in managing their water resources, planning hydropower development in co-operation with other water-using sectors, and take a full life-cycle approach to the assessment of the benefits and impacts of projects.