30 Apr 14
Originally posted by FabianFnasarr it just so happens I have done some internet research on this very subject:
A question about storing energy in a dam of water in a higher level:
You need energy when you pump up the water. How many percent of that energy do you get back when you let it down again in a hydro power plant?
I would think it is quite ineffective process...
http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity
"... energy efficiency varies in practice between 70% and 80%,[1][2][3][4] with some claiming up to 87%.[5] ..."
-Not too bad I suppose -but I think it surely can be made to be much more efficient! This is because the most energy efficient electric motors are about 98% energy efficient and I see no significant reason why they couldn't be designed to power ultra-low friction piston pumps (rather than turbines ) to pump water up into a reservoir with an energy efficiency of perhaps ~96% ?
30 Apr 14
Originally posted by humyMy guess is the loss of efficiency is not so much due to electromechanical losses in the motors but a lot of the loss coming from friction of the water flowing down pipes.
arr it just so happens I have done some internet research on this very subject:
http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity
"... energy efficiency varies in practice between 70% and 80%,[1][2][3][4] with some claiming up to 87%.[5] ..."
-Not too bad I suppose -but I think it surely can be made to be much more efficient! This is because ...[text shortened]... er than turbines ) to pump water up into a reservoir with an energy efficiency of perhaps ~96% ?
I would not be surprised to find work done to lower the friction co-efficient of water flowing in pipes would give them a better shot at 95+%.
For instance, coating the inside of the pipes with teflon for instance or some of these hydrophilic compounds Nissan just developed for car paint.