Facts about hydropower
Renewable hydropower is a reliable, versatile and low cost source of clean electricity generation and responsible water management.
Modern hydropower plants are accelerating the clean energy transition, providing essential power, storage, flexibility and climate mitigation services.
Hydropower is also a key asset for building secure, clean, electricity systems and reaching global net zero targets.
More factsheets:
Pumped storage hydropower | Regional interconnections
Greenhouse gas emissions | Green bonds | Resettlement
Fish and aquatic biodiversity | World Heritage and Protected Areas
Types of hydropower
There are four main types of hydropower plants: run-of-river, storage, pumped storage and offshore hydropower.
Only a small minority of the world's dams are built for hydropower, with the majority used for irrigation, water supply, flood control and other purposes.
Responsible water management
Many hydropower projects are used for multiple purposes beyond electricity generation, providing infrastructure to supply clean water for homes, industry and agriculture, as well as recreation and transportation services.
Hydropower projects can be used to regulate and store water to mitigate the impacts of extreme weather events such as floods and drought, which are on the rise due to climate change.
The single largest renewable energy source
Hydropower accounts for more than 50% of renewable electricity production globally. In 2022, the sector produced about 15% of total electricity generation from all sources.
In its 2021 Hydropower Special Market Report, the International Energy Agency (IEA) reports that hydropower accounts for nearly a third of the world’s capacity for flexible electricity supply and has the potential to provide even more.
No country has come close to achieving 100% renewables without hydropower in the energy mix. Hydropower installed capacity reached 1,416 GW in 2023. Conventional hydropower capacity grew by 7.2 GW to 1,237 GW, while pumped storage hydropower grew by 6.5 GW to 179 GW. China, Brazil, the USA, Canada and India are the largest hydropower producing countries by installed capacity.
Charging up variable renewables
Hydropower is an ideal complement to variable renewables like wind and solar, thanks to its flexibility and energy storage services.
Hydropower can meet demand when these intermittent sources are unavailable. Pumped storage hydropower, operating like a green, rechargeable battery, absorbs energy when supply exceeds demand. Water, wind and sun - get the job done!
Low-carbon and pollution-free
Hydropower is among the cleanest sources of electricity, with a low greenhouse gas emission intensity compared to other energy forms.
Independent research suggests that use of hydropower instead of fossil fuels for electricity generation has helped to avoid more than 100 billion tonnes of carbon dioxide in the past 50 years alone, exceeding even the emissions averted by nuclear power. That’s roughly equivalent to the total annual carbon footprint of the United States for 20 years.
Over the life cycle of a power plant, hydropower offers some of the lowest greenhouse gas emissions per unit of energy generated – as well as multiple environmental benefits. (IEA Hydropower Special Market Report 2021)
If hydropower was replaced by coal, IHA estimates 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. There would also be 150 million more tonnes of air polluting particulates emitted each year.
Future projections
The IEA and the International Renewable Energy Agency (IRENA), state that to achieve a cost-effective and feasible global net-zero energy system by 2050, the existing capacity of hydropower will need to be doubled - that is between an approximate range of 2,500 GW to 3,000 GW, including pumped storage hydropower.
The 2024 World Hydropower Outlook reported that up to 2030, a relatively small increase over the recent trend build rate, from about 20 GW/year up to about 25 GW/year, is required for hydropower to make its expected contribution to the 'tripling up' objective agreed at COP28.
After that, however, if net zero is to be achieved, delivery needs to be more than doubled, to about 50 GW/year, and this rate needs to be sustained until 2050.
Such growth would help generate some 600,000 skilled jobs over the coming decade and to double hydropower capacity by 2050, a cumulative investment of approximately US$3.7 trillion is required, or about US$130 billion annually.
Low cost over the long-term
Hydropower provides very low cost electricity over its long lifetime, despite relatively high upfront construction costs.
The global weighted average cost of electricity from hydropower projects in 2022 was US$0.061 per kWh, making it the lowest-cost source of electricity in many markets (IRENA).
Hydropower provides an opportunity to generate significant revenue from exports to neighbouring countries. In addition, the hydropower industry directly employs around 2.5 million people worldwide, and many more in connected supply chains (IRENA).
Hydropower Sustainability
Hydropower projects of all sizes can result in net-benefits to communities and the environment, provided they have a strategic fit in a river basin and are responsibly developed and operated.
Hydropower operators and developers can now demonstrate the environmental, social and governance (ESG) performance of their projects using the Hydropower Sustainability Standard, under the custodianship of the Hydropower Sustainability Alliance.
The certification system was launched in September 2021 and is widely recognised by the IHA, multilateral banks and civil society organisations.
The certification system builds on the Hydropower Sustainability Tools, a set of guidelines and assessment tools used over the past decade by hydropower developers, operators and financiers. Governed by a multi-stakeholder group of civil society, industry, governments and financial institutions, the tools are aligned with safeguards developed by the World Bank and other organisations.
Hydropower and the SDGs
Sustainable hydropower supports the achievement of the United Nations Agenda for Sustainable Development, as well as the Paris Agreement on climate change.
The 17 Sustainable Development Goals were adopted by all member governments of the United Nations and provide a blueprint of priorities for national governments, multilateral organisations, business and civil society.
When responsibly developed and operated, hydropower projects can directly support the achievement of SDGs 6, 7, 9 and 13:
Goal 6: Ensuring availability and sustainable management of water for all
Goal 7: Providing access to affordable, reliable, sustainable and modern energy for all
Goal 9: Upgrading infrastructure with clean, environmentally sound technologies
Goal 13: Taking action to combat climate change and its impacts
