[ziotom78]

Interesting! I wasn’t aware of pumped hydro. I checked one of the links in the thread, and it does look like a promising technology.

Has it been proven at the scale and reliability needed to balance a fully solar-dominated grid year-round?

[avhception]

The problem with pumped hydro seems to be that the places with the topography needed to create artificial lakes that lend themselves to hydro storage are rather limited. Other than that, it seems to be doing well!

[defrost]

Walpole has gentle hills, not mountains, and a farm dam full of water was sufficient for 30 MW hours of storage.

https://www.abc.net.au/news/2024-12-01/australian-first-mini...

Very few places are flat without hills ( Much of Mali is really flat, for example ).