Among the drivers, pumped hydro storage as daily storage (TED2.1), under the utility-scale storage cluster, was the most important driver, with a global weight of 0.148. Pumped hydro's ability to generate revenue (SED1.1), under the energy arbitrage cluster, was the second most prominent driver, with a global weight of 0.096.
A dynamic energy storage solution, pumped storage hydro has helped ‘balance’ the electricity grid for more than five decades to match our fluctuating demand for energy. Pumped storage hydro (PSH) involves two reservoirs at different elevations.
The total global storage capacity of 23 million GWh is 300 times larger than the world’s average electricity production of 0.07 million GWh per day. 12 Pumped hydro energy storage will primarily be used for medium term storage (hours to weeks) to support variable wind and solar PV electricity generation.
The 2024 World Hydropower Outlook reported that 214 GW of pumped storage hydropower projects are currently at various stages of development. Recent atlases compiled by the Australian National University identify 600,000 identified off-river sites suggesting almost limitless potential for scaling up global PSH capacity.
Pumped storage hydropower (PSH) is a form of clean energy storage that is ideal for electricity grid reliability and stability. PSH complements wind and solar by storing the excess electricity they create and providing the backup for when the wind isn’t blowing, and the sun isn’t shining.
Prospective off-river pumped hydro storage sites vary from tens to hundreds of hectares, much smaller than typical on-river hydro energy reservoirs. Tunnels and underground power stations, as assumed in the costing methodology, can be used in preference to penstocks to minimize other surface impacts.