I attached a PDF file of this unit. This is an actual ice maker using no electricity, it works on the same principal that the fridge in an RV uses with a pilot lite.

I believe the output is about 5 kg per square meter of collector, per sunny day so the one shown would probably produce about 50+ lbs of ice per day.

The property I am looking at has a natural spring on it & I am planning on building a spring house over it to keep animals & debris from dirtying the water but also as a cool place to store food.

The basic idea would be to have maybe an old bath tub filled with water that the unit freezes. Having that inside the cool spring house the ice would probably last for a few days. Shelves above the tub could store fresh veggies until they can be canned.

The unit would not need to be turned on or off.

I'm open to all suggestions & comments but I think this could solve storage problems & also transportation problems for those who are selling at markets. Insulate your van or trailer, make ice, put it in van or trailer along with the produce & go to market. What does not sell can be stored in the spring house.