There is plenty of water in the world for everyone, the problem has always been trying to convert it into a form we can drink. German Researchers at the Fraunhofer Institute recently announced that they have developed a new method to convert air humidity into drinking water using renewable energy. They are proposing large water harvesting plants to be located even in the most remote of places, such as the Sahara desert. Is this the solution to our water problems?
Getting water from thin air is actually not as difficult as it seems – the problem has always been how to do so in a cheap and relatively energy efficient way. The research was led by Siegfried Egner, head of the deparment at the Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB) in Stuttgart, in conjunction with Logos Innovationen. The most intriguing part of their research is how this concept can be adapted depending upon the demand for water. It can be adapted to suit individual needs as well as large-scale installations. So far, the researchers have been able to replicate this on a laboratory scale, though they hope to have a working facility up and running soon.
The innovative process works as follows: A saline solution known as hygroscopic brine absorbs moisture as it is drawn through a tower or chimney. The moisture-rich saline solution is then sucked into an underground tank, thanks to a lower pressure prevalent in the system, and is heated up by solar collectors installed in the roof. The lower pressure is the key in this process, as water is released from the brine at a temperature that is well below its boiling point. This evaporated water is collected and run down a completely filled tube, which in turn creates the lower pressure which drags down further liquid, thus creating a continuous loop within the system. This water is collected into a tank which can then be consumed.
There are still huge hurdles to cross before we see water harvesting plants like the one pictured above in cities everywhere. And indeed, there is no indication of what would be needed or how much they would cost. We have to say, though, that on principle, this seems like a worthy research project.
+ Fraunhofer ITP
Lead photo by Snapr