Clean Drinking Water for Everyone !

In previous posts, I have spent considerable amount of time pondering socially-aware topics such as Open-Source and Renewable Energy. While these seem like divergent topics, here is one opportunity for Open-Source principles and Renewable Energy to collide, providing us with something the world needs - more clean drinking water.

As all fourth-grade students know, some 75% of the planet is covered in water. Unfortunately, it is predominately salt-water, rendering it unsafe to drink. As we move further inland, and away from the oceans & seas, we encounter fresh-water. But being the wasteful & destructive beings we are, we pollute our own sources of clean drinking water ! So while we have access to all the water we could possibly need, we need to find ways to make more of it potable & usable.

Recently, I have been reading a lot about self-styled "Permies". These are people who have created a sub-culture dedicated to permaculture. The ideas behind permaculture are to mimic the ways in which Nature does things to create a more sustainable means of living on the planet. So everything from building rocket-stove mass heaters, to filtering water is within the aims of the sub-culture.

Of course, all of these systems require energy of some form. We see the need to pump water or generate electricity for these systems to work. Remarkably, many of the best solutions to these problems are actually hundreds (or in some cases, thousands !) of years old.

Take for example the Solar Water Still. By using the power of the Sun, water is heated enough to evaporate, condenses on a collector, and is collected as potable water ! This exactly mimics the way the Earth herself evaporates water into the atmosphere, which then falls later as rain. Early stills were actually used as a means of harvesting salt from ocean-water !

We know that rain-water is typically much cleaner than ground-water. This is because the natural process of evaporation distills the water to near 100% pure, leaving the salts & other heavy impurities behind. So it would seem obvious that we should drink rain-water where possible. But the opportunity still exists for other pathogens to exist in rain-water. The collected water still requires pasteurization to insure the pathogens present are killed off.

A solar still provides both of these methods, and even adds a few more ! By incorporating a few methods into one system, extremely pure water can be created, with zero additional energy being required.

First the rain water is collected in a catch-basin. It is then transferred by "wicking" (capillary action) into a bed of sand, which helps with the first phase of filtration. Next, the bed of sand is covered in an air-tight container & exposed directly to the sun's rays. The clear plastic cover allows UVA radiation to break down the DNA of the pathogens, effectively killing them !

As the sun heats the sand to 160F or more, the water evaporates into the air of the chamber & collects on the plastic cover, which is tilted at an angle towards the sun. The water vapour then condenses & runs down the surface of the collector to a central container. Voila ! 100% pure, naturally-softened, pathogen-free water, suitable for consumption by one & all.


The opinions expressed are purely those of the author. Opinions are like noses - everyone has one, and they are entitled to it !