> You see that "upper reservoir"? That's an alpine lake that forms the body of water that flows down through the penstock and drives the electric turbine.
The pressure is at the bottom of the penstock at the turbine. I'm not sure how you came to the conclusion that I wrote otherwise.
If the upper reservoir isn't raised - as in, an alpine lake - the there's no pressure in the penstock. Look at any picture of a hydroelectric storage facility:
If the upper reservoir isn't raised well above the river or lower reservoir, then there's no pressure to drive the turbines. If you didn't build the upper reservoir up high on a mountain forming an alpine lake, and instead built it on flat ground you'd just have a big useless pond. This is why geography is crucial for pumped hydroelectricity storage.
Pumped hydro requires an elevated reservoir ("news at 11!"). It does not, in fact, require an alpine lake. Nor does the upper reservoir need concrete construction, as the pressure on its dike, if in fact one is needed at all, is limited to the depth of the water in it.
You knew all of the above, but chose to lie about it.
> You see that "upper reservoir"? That's an alpine lake that forms the body of water that flows down through the penstock and drives the electric turbine.
The pressure is at the bottom of the penstock at the turbine. I'm not sure how you came to the conclusion that I wrote otherwise.
If the upper reservoir isn't raised - as in, an alpine lake - the there's no pressure in the penstock. Look at any picture of a hydroelectric storage facility:
https://i0.wp.com/esbarchives.ie/wp-content/uploads/2016/02/...
https://www.ecogeneration.com.au/wp-content/uploads/2016/12/...
https://i1.wp.com/www.cleanfuture.co.in/wp-content/uploads/2...
If the upper reservoir isn't raised well above the river or lower reservoir, then there's no pressure to drive the turbines. If you didn't build the upper reservoir up high on a mountain forming an alpine lake, and instead built it on flat ground you'd just have a big useless pond. This is why geography is crucial for pumped hydroelectricity storage.