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The world’s water battery: Pumped hydropower storage and the clean energy transition

18 December 2018

An additional 78,000 megawatts (MW) in clean energy storage capacity is expected to come online by 2030 from hydropower reservoirs fitted with pumped storage technology, according to this working paper from the International Hydropower Association (IHA).

Below are some of the paper's key messages and findings.

  • Pumped hydropower storage (PHS), 'the world’s water battery’, accounts for over 94 per cent of installed global energy storage capacity, and retains several advantages such as lifetime cost, levels of sustainability and scale. The existing 161,000 megawatts (MW) of pumped storage capacity supports power grid stability, reducing overall system costs and sector emissions.
  • A bottom up analysis of energy stored in the world’s pumped storage reservoirs using IHA’s stations database estimates total storage to be up to 9,000 gigawatt hours (GWh).
  • PHS operations and technology are adapting to the changing power system requirements incurred by variable renewable energy (VRE) sources. Variable-speed and ternary PHS systems allow for faster and wider operating ranges, providing additional flexibility at all timescales, enabling higher penetrations of VRE at lower system costs.
  • As traditional revenue streams become more unpredictable and markets are slow to appropriately reward flexibility, PHS needs to secure new sources of reliable and long term revenue in order to attract investment, particularly in liberalised energy markets. 
  • Driven by the increasing penetration of wind and solar, reduced dispatchable generation and the need for greater grid flexibility, an additional 78,000 MW or an increase of nearly 50 per cent of PHS capacity is expected to be commissioned by 2030. This could further increase with the right policy settings and market rules.

Read the press release