This last week we learned that there is frozen water at Mercury’s poles and that water has been detected by Curiosity in its exploration of Gale Crater. Water seems to be abundant in the Solar System but increasingly scarce here on Earth. I’m not talking about oceans of water but freshwater. In previous blogs on this subject we have looked at water stressed areas of the planet. Countries and continents are facing a freshwater crisis leading to major investments in the building of large-scale desalinization projects, harvesting freshwater from saltwater sources. But desalinization on this scale doesn’t work in poor countries, or in areas experiencing freshwater shortages far away from coastlines.
I wrote some time ago about capturing water from air using inventions like the Airdrop, a technology developed by an Australian to provide water for irrigation in dry environments. But Airdrop isn’t designed for people. It only works for plants. And plants are less discriminating about water quality than humans. That’s why companies like Coca Cola are joining with entrepreneurial inventors to find ways to create potable water for communities under freshwater stress.
One of those projects has led to the invention of the DEKA Slingshot, a vapour compression distiller that takes any non potable water (seawater, wastewater from sewage, agricultural runoff) and distills it into freshwater using very little energy (less than a kilowatt of electricity). A single Slingshot system can purify up to 300,000 liters (approximately 80,000 gallons) of water annually at the rate of 38 liters (10 gallons) per hour. Successful field trials in 2011 provided drinking water to 1,500 school children in Ghana for over six months with very few problems. What’s in it for Coca Cola? The company, through partnering with entrepreneurial inventors hopes to improve its water use efficiency to a point where it replenishes 100% of all water used in the production of its beverage products by 2020.
DEKA and Coca Cola are not alone in pursuing development of low-cost freshwater technology. Eliodomestico is a solar water distilling system that produces 5 liters (1.3 gallons) of drinking water daily. Invented by Gabriele Diamanti, Eliodomestico is open source. That is the plans for it are made freely available to anyone who wishes to manufacture it. Basic material requirements, terra cotta clay and zinc-plated sheet metal. How does it work? Eliodomestico uses solar heat to boil source water placed within it and then collects and condenses the water vapour.
Another solar distilling device, the Watercone, can transform saltwater into freshwater at the rate of 1.5 liters (50 ounces) per day, enough for a small child’s daily needs. Invented by Stephan Augustin, a native of Germany, and manufactured and distributed worldwide by Mage Water Management GMBH, this simple device, seen in the picture below, is made from a polycarbonate plastic. It works by evaporating salty or brackish water placed in its bottom dish using sunlight. The water vapour condenses on the inner wall of the transparent cone and collects in a trough around its bottom edge. Information I have been able to gather from the web indicates a range of pricing from 20 Euros to $69 U.S. The manufacturer’s purchasing page is currently down but I will revisit.
So from high tech, the Slingshot, to low tech, the Watercone, new devices are addressing freshwater scarcity on our planet. If you uncover solutions like these please let me know and I will write about them. The more we spread the word, the better our 21st century world can become.