It is a good thing, then, that pumped hydro is not limited to existing dams, or even to places where a hydroelectric power station would be practical. Pumped hydro does not need the large watershed and elevated river valley a hydroelectric dam needs. All pumped hydro needs is an elevated depression somewhere not too porous. There are myriads of those, and building a penstock up to one is very cheap.

Some places have no hills, so are not candidates for pumped hydro storage, and would need to rely on something else, such as long-distance transmission lines, or liquified air, or synthesized hydrogen, or synthesized ammonia, or underground compressed air, or iron-air batteries, or numerous others, or (most usually) some combination of them.