More frequent blackouts and reverting to the use of fossil fuels could be on the cards unless urgent action is taken to scale up pumped storage, warns a government-led coalition.

The warning comes from the International Forum on Pumped Storage Hydropower, a grand coalition of 13 governments led by the US Department of Energy, the International Hydropower Association (IHA) and involving more than 70 multilateral banks, research institutes, NGOs and public and private companies, which has set forth seven major recommendations to avert the risk of policy-makers and grid operators falling back on fossil fuels to provide clean energy storage.

The International Forum was formed in November 2020 to research practical recommendations for governments and markets aimed at addressing the urgent need for green, long-duration energy storage in the clean energy transition. It is co-chaired by Malcolm Turnbull who as Prime Minister of Australia 2015-2018 spearheaded the development of pumped storage hydropower (PSH) including the 2 GW Snowy 2.0 project and the Battery of the Nation initiative. Mr Turnbull has warned the lack of adequate long duration energy storage to support growing penetrations of solar and wind power is “the ignored crisis within the crisis”.

In its summary report, the partners to the International Forum warn that conventional batteries alone cannot provide adequate storage and grid flexibility. “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,” it says.

It warns that, unless governments are willing to retain power plants fired by fossil fuels, they will need to invest in the clean energy storage provided by pumped storage hydropower. “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 report says.

The seven major policy recommendations which governments are urged to follow are:

  1. Assess long-term storage needs now, so that the most efficient options, which may take longer to build, are not lost. 
  2. Ensure consistent, technology neutral comparisons between energy storage and flexibility options. 
  3. Remunerate providers of essential electricity grid, storage, and flexibility services. 
  4. Licensing and permitting should take advantage of internationally recognised sustainability tools. 
  5. Ensure long-term revenue visibility with risk sharing to deliver the lowest overall cost to society. 
  6. Assess and map for pumped storage hydropower among potential existing hydropower assets and prospective sites.  
  7. Support and incentivise pumped storage hydropower in green recovery programmes and green finance mechanisms. 

The full reports from each of the International Forum’s working groups are available online at