Planet Earth is now home to some 7.5 billion people. In spite of the ever-increasing population and life expectancy figures, one of the sad truths of our world is that more than one in 10 people do not have access to clean drinking water - but all that might be about to change.
Researchers at the State University of New York have created a portable solar still, which is a technology that will allow people to generate their own drinking water much like they generate energy with solar panels.
Solar stills have actually been around for millennia. They’re essentially black-bottomed vessels that filled with water after it has been trapped using a clear material (such as a sheet of plastic). The suns heats up the black container, causing the water to evaporate and become trapped in its upper layer, leaving contaminants and dirt behind.
The problems with solar stills to date have been the cost to set one up, and the amount of surface area required to produce an adequate amount of clean water each day. The researchers at the State University of New York managed to improve the ancient design in two fundamental ways, namely ensuring that it’s just the topmost layer of the water that gets heated for less lost energy, and employing materials that would make the new solar still design viable for the poorest people in the world to own.
Materials include a fiber-rich paper, similar to the paper used to print currency on, that’s coated in carbon black. The latter is a cheap powder that is left as a by-product of oil and tar production. Polystyrene blocks are also cut up and turned into 25 connected sections.
The polystyrene foam allows the solar still to float on the surface untreated water and acts as an insulating barrier, preventing sunlight from heating up too much of the water below. Evaporated water is trapped by a clear acrylic cover before being funneled into a collection vessel.
According to a report on the new solar still design, it channels the energy in sunlight into evaporating water with 88% efficiency. This level of efficiency allows the new design with a 1-square-meter surface area to purify 1 liter of water every hour, which is four times faster than commercially-available solar still designs.
At an estimated cost of just $1.60 per square meter, providing the minimal level water needed to sustain a family of four might cost as little as $5 per solar still. Are we on the cusp of a water revolution? Only time will tell.
Content and image source: The Plaid Zebra
Second image by Deposit Photos.
