Energy shift creates opening for 'world's largest batteries'

https://techxplore.com/news/2022-04-energy-shift-world-largest-batteries.html

"closed-loop" systems that tap a surface or underground supply, then repeatedly cycle that water between reservoirs... pipe water between two 60-acre (24.3-hectare) reservoirs... could power nearly 500,000 homes for up to 12 hours... hundreds of abandoned U.S. mines that could host pumped storage, with upper reservoirs and lower ones below ground. They are close enough to transmission and distribution infrastructure and to solar and wind generating facilities"

Related:

Hydropower technology turning even low-lying hills into green power stores

https://www.rechargenews.com/energy-transition/-no-water-hydropower-technology-set-for-full-scale-debut/2-1-1635557

Low-viscosity waterless high-density hydro storage could expand tech’s reach
https://spectrum.ieee.org/pumped-hydro-storage-rheenergise