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Fast facts about hydropower

Briefing for media and researchers:

  • The energy sector, the largest source of global greenhouse gas emissions, must decarbonise to meet the challenge of climate change. Renewable hydropower plays a key role in reducing the world's dependence on fossil fuels and avoiding harmful air pollutants.

  • In a world in which almost 1 billion people still do not have access to electricity (IEA 2018) and 2.1 billion are without safely managed water supply (WHO 2017), hydropower is a reliable and affordable source of low-carbon electricity and freshwater management.

  • Hydropower supports growth in variable renewables such as wind and solar, through its flexibility in dispatch and storage services, meeting demand when these sources are unavailable, and absorbing energy when there is a surplus.

  • Multipurpose hydropower reservoirs deliver a vital means of managing freshwater, providing supplies for agriculture, homes and business, and mitigating the impacts of extreme weather events such as floods and drought.

  • The world’s hydropower installed capacity rose to 1,292 gigawatts (GW) in 2018, generating a record 4,200 terawatt hours (TWh). (2019 Hydropower Status Report).

  • Hydropower is among the cleanest sources of electricity, with an estimated median greenhouse gas emission intensity of 18.5 gCO2-eq/kWh (2018 Hydropower Status Report).

  • If hydroelectricity was replaced by coal-fired generation, up to 4 billion tonnes of additional greenhouse gases would be emitted annually, increasing global emissions from fossil fuels and industry by 10 per cent each year. There would also be an additional 148 million tonnes of air polluting particulates, 62 million tonnes of sulphur dioxide, and 8 million tonnes of nitrogen oxide emitted each year (2018 Hydropower Status Report).

  • Despite high upfront costs, hydropower provides very low-cost electricity over its long lifetime. The global weighted average cost of electricity from hydropower projects in 2017 was USD 0.05 per kWh, making it the lowest-cost source of electricity in many markets (IRENA 2018). In addition, hydropower provides an opportunity to generate significant revenue from exports to neighbouring countries. 

  • Hydropower projects of all sizes can result in net-benefits to communities, energy systems and water security, provided they have a strategic fit in a river basin and are developed and operated sustainably.

  • Internationally recognised Hydropower Sustainability Tools exist to ensure that hydropower projects can be developed and operated in accordance with good practice. These tools comprise the Hydropower Sustainability Guidelines on Good International Industry Practice (HGIIP), the Hydropower Sustainability Assessment Protocol (HSAP) and the Hydropower Sustainability ESG Gap Analysis Tool (HESG).

  • The Hydropower Sustainability Tools were developed by a multi-stakeholder group of civil society, industry, governments and financial institutions, and are aligned with safeguards and frameworks developed by the World Bank, International Finance Corporation and the Equator Principles group of commercial banks.

Last updated: 10 May 2019