Solar stills.
There seems to be a lot of confusion about 'Solar Stills'.
What ANY still, solar or otherwise, does is condense moisture vapor back into liquid water.
YOU DO NOT HAVE TO BOIL THE WATER TO GET IT TO VAPORIZE.
Ever seen a cold glass condense clean, drinkable water on the outside of it sitting at room temprature?
Same principal, but we are capturing the water condensate.
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You can use a plastic bag on a tree branch with leaves to capture and condense the moisture being expelled by the tree.
That is one type of 'Solar Still'.
You can put anything containing moisture in a container and put a water tight cover over it, set it in the sun, and it will 'Sweat' drinkable water.
Even poisonous plants will yield clean water in a solar still.
In the jungle during survival training, we simply used a hole in the ground with a plastic poncho liner over the hole.
The moisture in the ground provided more than enough water vapor to fill up a two quart canteen daily.
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I use a table sized solar still to extract clean water for cooking when we were first starting to build at the river.
It was nothing more than a box with glass front face that angled to meet the sun.
The lower side of the glass made a natural drip edge, and a piece of PVC cut long ways made a good catch tray for the clean water.
River water, fruit/vegetable peelings, even urine can go into the 'Tank', and clean, drinkable water will come out.
Here is a link to making your own...
Solar Water Distillation
The first one I made was out of cardboard and black plastic/clear plastic.
Once the 'Proof Of Concept' worked,
I built mine out of an old Formica counter top and use fiberglass boat hull repair resin to water proof everything.
I used half of a PVC tube as catchment and the bottom edge of face glass as drip edge, and it seems to work just fine that way!