No. No "really" believes that. It's just another P&D pinky share selling operation. Someone posted a lengthy proof of the physics and even if you give SWET ideal lossless machines, they are not going to get enough energy out of this giant toilet tube to generate the electricity required to pump all that water at pressure to the height they claim.
This pos is marking new 52 week lows every week.
Well, yes, but it really reduces to the knapsack problem in that case. Do you have some kind of heuristic, or are we dealing with an NP-complete case?