Solar Still

A simple, cheap solar still that folds flat

In about 2 minutes you can make a simple solar still from common materials costing just a few pennies. One would not be enough to survive on, but since they are light and a half dozen small ones could fold into pocket size, it could keep you alive in the wilderness or if adrift.

Top of the outer bag is sealed.
(Side view)


This one uses a square of styrofoam from a take-out box. The material is cut from a pair of old black denim pants. The bags are 1 sandwich size, and one 1qt. size.


Finished still ready for use or storage. You can see the staples at the top of the sandwich bag.

On a boat or rubber raft they could be strung along the sides, or arranged on the deck since they will stand by themselves.

A cool fall day under less than ideal conditions (high thin clouds and windy) a 1 Qt freezer bag produced almost 1 oz of distilled water an hour. It will work at a reduced volume if it is cloudy. Good efficiency is possible because only the wick has to be heated instead of a large volume of water. Plus, the wick increases the surface area.

Material for the wick can be an old dark or black towel, of cut from an old pair of black Levis (denim).

The stiff plastic (with a single staple through it, the cloth and the upper edge of the inner bag) shown in the drawing could come from a  plastic can lid or the sides of a milk carton. Its purpose is to prevent collapse of the inner sandwich bag and contaminating the distilled water.

Aluminum foil taped to the Sun side helps prevent the distilled water from evaporating again. The inside surface of some brands of  bags of potato chips would work well.

Gallon size bags would of course provide more water than smaller ones. Of course, the outer bags can be used for storage until needed as a still.

This is not patented or copyrighted. Use it as you wish as long as you give credit to this website.