The International Forum on Pumped Storage Hydropower, warn in a report that conventional batteries alone cannot provide adequate storage and grid flexibility.

The government-led coalition says the world should get used to blackouts or risk reverting to fossil fuel as calls to scale up long-duration storage to support fast-growing solar and wind energy sources ramp up.

The International Forum on Pumped Storage Hydropower is a coalition of 13 governments, led by the US Department of Energy, the International Hydropower Association (IHA) and involving more than 70 multilateral banks, research institutions, NGOs and public and private companies. The Forum was formed in November 2020 to research practical recommendations for governments and markets to address the need for green, long-duration energy storage in the clean energy transition.

Convening three industry-led working groups, this year-long initiative will develop guidance and recommendations about how sustainable pumped storage hydropower could best support the energy transition. The IHA acts as the secretariat to the Forum.

In its summary report, the partners to the International Forum asked: “What happens when the sun does not shine and the wind does not blow? These technologies need a low carbon back-up or we will fall back on fossil fuels or simply have to get used to blackouts.”

“Without adequate storage, there is a very real risk that electricity grids of the future will not be able to provide reliable power without recourse to high carbon sources of back-up such as gas turbines.”

The Forum warns that unless governments are willing to retain power plants fired by fossil fuels, they should invest in the clean energy storage provided by pumped storage hydropower.

A clean, green water battery

The Forum points out pumped storage hydropower is an ideal complement to modern clean energy systems as it can accommodate for the intermittency and seasonality of variable renewables such as wind and solar.

A new IHA report, Hydropower 2050: Identifying the next 850GW towards 2050, says pumped storage installed capacity is set to more than double in the next few years. However, this remains well short of energy storage requirements of electricity grids which are increasingly becoming reliant on solar and wind power for generation.

By the end of 2020, 160GW of pumped storage hydropower had been installed globally, making up 95% of all total installed energy storage.

China has installed the most recent growth in pumped hydropower storage. Earlier this year they announced plans to double national capacity to 120GW by 2030. That would be a fourfold increase from 32GW today in less than ten years.

In Europe, the European Commission’s new Taxonomy on Sustainable Finance recognised pumped storage hydropower as making a substantial contribution to climate change mitigation.

Yves Giraud, EDF Hydro CEO said pumped storage hydropower projects should be better acknowledged for the services they bring to the electric system – flexibility, ancillary services needed to develop variable renewable energies, such as wind and solar: “In my opinion, in Europe and many countries worldwide, there should be a new market design to integrate storage facilities. Pumped storage hydro is highly valuable and key enabler of energy transition, we have all the tools to develop it in a sustainable way, so that it could play this major and vital role in decarbonisation of electricity.”

In the US, the American Jobs Plan calls for new investment in pumped storage hydropower, with tax credits and a new clean electricity standard to incentivise development.

Major policy recommendations for pumped storage hydropower

The International Forums put forward seven major recommendations for governments around the world to avert the risk of policy-makers and grid operators falling back on fossil fuels to provide clean energy storage:

Assess long-term storage needs now so that the most efficient options, which may take longer to build, are not lost.

Ensure consistent, technology neutral comparisons between energy storage and flexibility options.

Remunerate providers of essential electricity grid, storage and flexibility services.

Licensing and permitting should take advantage of internationally recognised sustainability tools.

Ensure long-term revenue visibility with risk sharing to deliver the lowest overall cost to society.

Assess and map for pumped storage hydropower among potential existing hydropower assets and prospective sites.

Support and incentivise pumped hydropower in green recovery programmes and green finance mechanisms.

Uwe Wehnhardt, Voith Hydro President and CEO, said: “We need pumped storage hydropower because it helps avoid the curtailment of renewable energy and reduces reliance on thermal power plants. These facilities provide essential grid services such as rotating inertia and reactive power and provide a means to respond quickly to the risk of blackouts.”

All the International Forum’s reports were launched at the World Hydropower Congress on 16 September.