alt.energy.homepower

"BobG" wrote in message
news: @ ...
> What would be inefficient? The pump impeller? Pump motor could be very
> efficient. The pelton wheel turbine is pretty efficient. The turbine
> could spin a pma alternator that is pretty efficient. The water and
> the tanks wont wear out like a couple of batteries would. Can you pin
> down 'enormously larger than two batteries' a little more
> quantitatively?

I think a lead acid battery can be ballparked at about 80% efficiency. We
would also lose a bit in the charge controller and wiring, so let's be
pessimistic and call it 70% efficiency for the battery storage system.

In the water storage system, each of the individual parts can each be
pretty efficient, but the problem is that you have a pretty long chain of
losses. Lets say the motor, generator, pump and turbine are each 90% efficient.
If so, then we can calculate .9 X .9 X .9 X .9 = 65% efficiency. But
unfortunately we are not done, because we have to consider flow losses and
evaporation, so you might ballpark our water storage system's efficiency at
something like 50%. But we are still not done because there are several hours
per day where the solar panels are not making enough power to start and run the
pump, but they could be usefully charging a battery.

Vaughn