Report identifies 300 GW gap in hydropower needed to limit global warming

More than 500 GW of hydropower installations are in the pipeline worldwide, but this is far short of what is required to limit dangerous global warming.

This is the conclusion of a major new report, ‘Hydropower 2050: Identifying the next 850+ GW towards 2050’, by researchers from the International Hydropower Association (IHA), published today at the World Hydropower Congress.

The report assesses pathways to net zero modelled by the International Energy Agency (IEA) and International Renewable Energy Agency (IRENA), against current and future planned hydropower capacity.

Both IEA and IRENA models assess that in order to keep global warming to below 2°C, around 850 GW of new hydropower capacity will be required by 2050 – amounting to a gap of more than 300 GW based on the current pipeline.

For the more ambitious net zero target to limit temperature rise to below 1.5°C, more than 1,200 GW of additional hydropower capacity will be needed – leaving a gap of over 600 GW.

‘Policy-makers need to take urgent action now to bridge this gap’

One of the report’s authors, Alex Campbell, Head of Research and Policy at IHA, said: “Hydropower’s highly flexible, low carbon generation and storage capabilities will have an essential part to play in the electricity grids of the future.

“Our analysis shows that, even if we built all the 500+ GW of projects in the pipeline, we will still be a long way short of the sustainable hydropower required to keep global warming below 2 degrees, let alone achieve net zero emissions. Policy-makers need to take urgent action now to bridge this gap.”

Among the more than 500 GW in the pipeline, just 156 GW of this is under construction, with another 165 GW approved by regulators. The rest has been announced or is pending approval.

This remains significantly below the contribution required from hydropower under the IEA and IRENA models to reach net zero emissions. In 2020, annual growth in installed capacity was just 1.6 per cent - lower than the minimum 2 per cent growth required.

Led by demand in China, the East Asia and Pacific region has 240 GW of future projected capacity planned, permitted or under construction. The next few years could see sizeable growth in Africa’s hydropower capacity, with 118 GW currently in the pipeline. In addition, South and Central Asia will see 91 GW in additional capacity.

Hydropower accounts for around 17 per cent of global electricity generation today. In 2020, global installed hydropower capacity reached 1,330 GW. The sector generated a record of 4,370 TWh of electricity that year, roughly equivalent to the annual electricity consumption of the United States.

Future hydropower potential by region

Outside of China, the pace of development remains slow and unlikely to meet IEA and IRENA model targets without action by governments to incentivise new developments. Moving from understanding the global potential to actual deployment will therefore take huge political will and enabling market mechanisms, concludes the report.

The report highlights future potential in regions where hydropower is less developed, as well as the centrality of hydropower for many countries’ shifts towards renewable energy and extending electricity access to growing populations.

Future hydropower potential by type

The report also confirms the growing importance of pumped storage hydropower as a source of long duration energy storage in the clean energy mix. Available data shows that current installed capacity in the world’s ‘water batteries’ will almost double if all projects in the current pipeline are completed.

In regions where hydropower is more developed, such as Europe or North America, electricity generation capacity can be added by modernising older plants. There is further potential from retrofitting dams that are currently not used for electricity generation.

Recommendations to bridge the gap

Policy recommendations that could help incentivise new sustainable hydropower projects and bridge the gap between planned versus needed capacity include: better remunerating hydropower for its grid system services and streamlining licensing and permitting processes, and improving regulatory frameworks to promote plant upgrades and modernisation.

In addition, companies are encouraged to adopt sustainability standards to reassure investors, to build climate resilience into planning and operations, and to consider retrofitting non-powered dams with hydropower.

Download the report at

Notes for Editors:

The 2021 World Hydropower Congress, 7-24 September, brings together industry, governments, multilateral and financial institutions, civil society and community groups to set priorities for future hydropower development. The online, free-to-access event will showcase how sustainable hydropower – the world’s largest renewable energy source – is part of the solution to climate change.

Ahead of the UN Climate Change Conference (COP26), this is an opportunity to hear how the massive roll-out of solar and wind power is dependent on the clean generation, storage and grid resilience services offered by sustainable hydropower.

The World Hydropower Congress will see a range of other announcements and commitments made by and on behalf of the hydropower sector.

On 16 September 2021, the International Forum on Pumped Storage Hydropower, co-chaired by the US Department of Energy and former Australian Prime Minister Malcolm Turnbull, will publish three new reports on the future of the world’s water batteries.

Media Contact:

Will Henley

Head of Communications

International Hydropower Association

The World Hydropower Congress Secretariat

Telephone:  +44 797 423 0904  


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