I have thought the same thing on the water idea. I have seen some YouTube video's with an old Stirling Engine they used to use to pump water into a holding tank for cabins and hotels. The stirling just uses heat to power it. So they used to fire it up first thing in the morning by lighting a fire under it and then just let it run until the fire went out. That would pump enough water to supply the buildings. So imagine using something like a fresnel lens to heat that engine and pump water or run a generator? You can see a fresnel lens used on a small stirling engine also on YouTube. It is almost a no brainer! There are a couple of videos showing the fresnel lens "melting" concrete!
To me it looks like you would just need something to allow the fresnel to move and track the sun to keep the stirling running. The stirling is an old technology. The one video on YouTube shows a Sterling from 1895 that was used to pump water.
Wind to pump water has been done for a long time, and again seems like a no brainer. Not sure why this isn't being discussed. Probably makes too much sense!
Longsnowsm