> Some claim an existing elevated lake is needed, which is false. An earthen dike at a hilltop suffices. Such a dike may be needed only at one end of the reservoir.
This seems like an over simplification. At a minimum it needs to be an earthen dyke on a strata suitable for retaining water, right? It needs to be located in an appropriate area, near suitable grid infrastructure to ship the power out and road access to get workers and equipment in. Lots of mountainous regions are highly valued for their natural beauty which makes large infrastructure projects more challenging.
("Dyke" is a wholly different noun. I advise against its use until you understand it better.)
The bottom of the reservoir needs to be impermeable. It is well understood by civil engineers how to achieve this.
Earth-moving equipment is very good at getting to places you would not want to try driving your car into (unless, I gather, you are French). Generation and pumping equipment remains at the bottom of the hill. An earthen dike on a hilltop can be as inconspicuous as you care to make it.
You do need wires from there to where the power is, as usual.
> "Dyke" is a wholly different noun. I advise against its use until you understand it better.
Perhaps you could refrain from making snarky comments about minor spelling errors which clearly didn't impact your understanding until you understand dyslexia better?
> The bottom of the reservoir needs to be impermeable. It is well understood by civil engineers how to achieve this.
Understood isn't the same as economically feasible. It's not a trivial issue.
> Earth-moving equipment is very good at getting to places you would not want to try driving your car into
Earth-moving equipment isn't designed to make long distance overland journeys. They are typically delivered to a work site at most hundreds of yards from where they are needed.
> Generation and pumping equipment remains at the bottom of the hill
You still need to get the equipment there so the bottom of the hill needs to be near a road. And you don't want miles of penstock because that will reduce the dynamic head pressure due to friction losses.
The point is there are constraints which you are pretending just don't exist.
There are always constraints. But technology for building roads adequate for transporting heavy machinery, and for building hilltop reservoirs using it, is extremely mature.
Dozens were built in California's Sierra Nevada range in the 1920s using pulley-operated equipment. Those were actually hydro power reservoirs feeding penstocks that have since had pumps attached.
Power loss from flow in penstocks is typically negligible.
It's doubtful anyone genuinely believed that an offensive term for a lesbian was the most appropriate parsing of that sentence. It's just a bad faith argument and I'm you understand that.
This seems like an over simplification. At a minimum it needs to be an earthen dyke on a strata suitable for retaining water, right? It needs to be located in an appropriate area, near suitable grid infrastructure to ship the power out and road access to get workers and equipment in. Lots of mountainous regions are highly valued for their natural beauty which makes large infrastructure projects more challenging.