Considering the "premium" now paid (at least in NSW) for renewable power, via the FIT, has anyone thought of using an efficient 3 ph "grid" powered pump (Mono or multi-stage centrifugal) to pump water uphill and then let it run back down through a mini hydro to feed back into the grid.
In fact, why even pump it up the hill? Just out of the pump into the hydro!
Still better, why even pump water.......just have the motor turning an alternator?
If both the motor and alternator are 90% eff. then I get back 80% of what I put in. That is more than compensated for by the "up to 46c/kWh" premium FIT.
Just thought I'd throw this in for debate.
Ethical or not?