Emergency Drinking Water: Types of Solar Still

In any survival situation lasting more than a few hours, finding a source of emergency drinking water is going to be a concern. One innovative trick to be aware of is harnessing the power of the sun to collect and purify drinking water in a solar stills. There are three main types of solar stills: the pit solar still, the cone solar still and the box solar still. These are all items that you can make on your own, although there are commercial solar stills such as the Water Cone that are available as well.

Pit Solar Still

Pit shaped solar stills are the simplest solar still to make and require little equipment or technical know-how. Simply dig a pit in the earth approximately two feet deep and place a Number 10 sized can at the bottom. If available, set a drinking tube in the bottom of the can leading out of the hole. Then secure a sheet of plastic over the hole a place a stone in the sheet so that it indents the sheet to just above the can's lid. So long as this solar still receives plenty of sun, it will provide a pint or more of emergency drinking water.

Cone Solar Still

A cone shaped solar still is a method of treating impure emergency drinking water rather than gathering it from the atmosphere. A cone is constructed out of plastic designed so that impure water in the bottom evaporates and is captured in a makeshift reservoir as it runs down the side, relieved of impurities. The Watercone is commercial solar still that allows you to distill water naturally at home or on the go with having to construct a solar still of your own. Designed as a water purification system that can generate potable water out of even brackish sea water, the Watercone is also a candidate for providing clean drinking water in developing and failed nations.

Box Solar Stills

The box shaped solar still is fairly complex compared to the other solar stills made for obtaining pure emergency drinking water. This type of still is usually created with a box that has a slanted glass or plastic top with an insulated bottom. A set of tubes allow in impure water and let out over flow and pure distilled water. Maintaining a tight seal on a box shaped solar still is essential. Clearly, this is more of a home project for a green minded person, but having a solid understanding of how all solar stills work might come in handy when trying to construct one from scratch for emergency drinking water.

Sources:

http://en.wikipedia.org/wiki/Solar_still
http://www.desertusa.com/mag98/dec/stories/water.html
http://www.ehow.com/how_12584_make-solar-still.html
http://www.watercone.com/product.html
http://www.homepower.com/article/?file=HP130_pg28_ATE_3