MikeWhy wrote:

Locking against heavy loading would seem to suggest a worm. PV? A
Stirling pumped "hydraulic" motor/water wheel? I know... complexity.

PV plus motor plus worm drive is certainly an attractive route, but too
expensive and not suited for local production and maintenance.

It needs to be really simple and so inexpensive that it's not worth
stealing. For context, rural Somalia might be one of the target "market"
areas.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/