I do understand that potential energy is based on the height of an object. In this case it being water. But what happens when you add multiple hydroelectric dams on a strech of river. Can we add infinite dams or is there a limit?
– Sal via the Ask a science question page.
There is a limit. And this limit depends on the height of the river. So as long as you have a height you can build dams in a cascade fashion and run a hydroelectric powerplant. The limit ends where the height reaches the sea level. You will be better off building one plant at a very steep area of the river than building consecutive installments as the river water starts losing kinetic energy and height down the stream.