Science Buddies: "Ask an Expert"

My hypothesis is "Can an Archimedes Screw be Adapted to Solar Power Source?" I have a real life application for a
full scale screw.
Background
The hilly village of Chiapas Mexico has poor people. This summer I met a missionary who built 2 trade schools and a clinc for this village. Few of the people have water wells. Drilling is a luxury. If a communty well is made in a low lying area then others can share the water using the screw pump. I want to rephase my question so it matches with the purpose,
Purpose: How much water can be moved per day with a 4.0 volt solar powered screw?
John

This is an interesting question, and I think you've adapted it very well.

First off, I think you care about the *power* output of your solar array, rather than the voltage. To be useful, it's likely that the voltage will have to be "stepped up" using a transformer anyway. Most electric motors that could run an Archimedes screw efficiently will probably run on either 12VDC or 110VAC.

To answer your question analytically, you would need to know the efficiency of your motor at converting power into motion, as well as the efficiency of the screw (which will depend on factors like the load, the friction, etc.).

It's probably a lot easier to measure the efficiency of the screw experimentally (most motors specifications will tell your the motor's efficiency, or you can find it somewhere online, but measuring it would be more accurate).