Suppose along a river which is descending a mountain.On the river there are 10 hydropower stations A,B,C......J suppose at distances of 10km each.Now each station producees 100MW Power.So we get 1000MW. My Question is 'In this way can we produce as much power as we require by increasing number of stations on the same river at our discretion?'
As you can imagine, each station is extracting energy from river, so somehow something must be "adding" energy to the river before it can be extracted. Can you think of what that "something" may be? Hint: you already referred to it in your post, but perhaps without thinking about exactly what it means in this situation.
I understand that potential enery and kinetic energy as well of water is getting converted to rotational energy of turbine wheels at each stage.But still can we get energy at our discretion?
One turbine for the full drop produces twice the power of 2 turbines with half drop, and so on. The total energy available from the drop does not change by adding more turbines along the way. In fact, there will be some optimum number of stations that minimize the losses in the conversion, but the total power output will still have a maximum that is a bit less than the total energy stored in the water drop.
Well as long as after each station there is maintained the same amount of water and the same decrease in height (gravitational potential of the flowing water) the you could extract the same amount of power as in the station before but you realize that in real life rivers dont flow just downwards also they are not infinitely long so that puts a limit on how much hydro power plants we can physically put on a single river so that each of them would be useful.