Quick Answer
A solar still is a suitable option for survival situations in the wilderness, providing a reliable method for purifying water using the sun's energy. This method is especially useful in arid or desert environments where water sources are scarce. It requires minimal equipment and can produce a steady supply of clean drinking water.
Design and Setup
To build a solar still, gather a shallow container (at least 6 inches deep and 12 inches in diameter) and a smaller container or cup. Place a layer of small rocks in the shallow container, followed by a cloth or plastic sheet, and finally the smaller container. Weigh down the center of the smaller container with a rock to create a depression. This setup allows for the collection and condensation of water vapor.
Water Collection and Purification
Add contaminated water to the shallow container, making sure not to submerge the smaller container. As the sun heats the water, water vapor rises and condenses on the underside of the plastic sheet or cloth. The condensed water then drips into the smaller container, creating a steady supply of clean drinking water. Aim to collect at least 1 liter of water per day, depending on the intensity of the sun and the design of the still.
Efficiency and Considerations
A solar still can be an efficient method for water purification, with some designs able to produce up to 2 liters of water per day. However, the process can be slow, and it’s essential to consider the amount of sunlight available, the design of the still, and the initial source of water. To optimize the still’s performance, use a dark-colored container to absorb more sunlight and ensure the still is level to prevent water from seeping out.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.