> Pumped storage is a fine technology, but is there a lot of build potential left for it? "A lot" is probably subjective, but the two best known global estimat

> Pumped storage is a fine technology, but is there a lot of build potential left for it? "A lot" is probably subjective, but the two best known global estimates are Hunt et al. (2020) [1] from IIASA and Stocks et al. from ANU re100 (who incidentally also have some interactive maps [3]) which with different cost targets put potential at 17.3 and 23 PWh respectively, which works out to about 2 MWh per person. For comparison, for the past decade, the US ahs consumed about 13 MWh of electricity per person per year, down from a peak of slightly under 14 in 2000 and 2005. With very high levels of electrification, that could potentially rise to 24 to 28 MWh per person per year, or 8 or 9 PWh/yr for the whole country. Total primary energy use is a lot higher, around 90 MWh per person–year or 30 PWh total, this is because both not everything could be practically electrified and the things that could easily be electrified tend to be much more efficient when done electrically. Energy efficiency is also usually assumed to increase slightly in general. The US specifically is actually above the world average at about 4.5 MWh per capita according to the ANU team's estimates. That's 1.5 PWh per year roughly. In any case, I would expect that there is likely to very likely sufficient potential in most (if not all) grids for pumped hydro to be a significant part of medium duration energy storage (if not all of it), though whether it actually would depends on the costs of other technologies as well. [1]: https://doi.org/10.1038/s41467-020-14555-y https://doi.org/10.1038/s41467-020-14555-y [2]: https://doi.org/10.1016/j.joule.2020.11.015 https://doi.org/10.1016/j.joule.2020.11.015 [3]: https://re100.eng.anu.edu.au/ https://re100.eng.anu.edu.au/