[Timshel]

Interesting but it appears to only take account the topographic feasibility of the project.

The first location I looked at (link is not working :(), it relies on building two dams on rivers (which is something we tend to do less not more) and would flood some houses ...

And there is supposedly a price estimate, but it's just an A, B, C, D or E ranking could not find some costs to make comparison with battery storage for example.