Aug 24, 2016: Most of the people are aware that solar stills help to make seawater or tainted water drinkable. However, in order to generate more than a trickle, devices usually involve costly lenses or other tools. But, not any longer! Researchers have come up with a cheap solar still made up of bubble wrap along with other simple materials that will ensure cleaning drinking water for all.
About the experiment
A 2014 research headed by Gang Chen, a mechanical engineer at the Massachusetts Institute of Technology in Cambridge, introduced a competent solar absorber made up of layer of graphite on floating carbon foam. The two layers were punctured, permitting the water below to wick up to the graphite, where it got warmed by the sunlight. The solar absorber worked, however majority of the energy in the sunlight radiated away. In order to boil water, the solar still required extra devices to concentrate 10 times the ambient sunlight to beat the infrared losses.
Now for their present experiment, the researchers have substituted the graphite solar absorber with a thin coating of a bluish metal and ceramic composite material. This material helps in absorption of ultraviolet rays from the sun, but it doesn’t emit heat in the infrared. Next, the researchers placed a thin sheet of copper between the coating and the foam and then, punched holes through the sandwich like layers.
However, a problem still remained. Majority of the energy absorbed by the compound was being brushed away by convection, heat lost to the air moving above the solar still’s top surface. However, the issue was solved when the researchers covered the solar still in bubble wrap.
Now clean drinking water for all with cheap solar still
Creating a cleansing system would be no small mission. Chen estimates it would require 20 to 40 square meters of the solar still material to provide 50 liters of water on a daily basis.
No extra solar concentrator
The setup paves way for water to be boiled and distilled with no extra solar concentrator. This will facilitate in make large-area solar stills for about one-twentieth the price of conventional technology, according to researchers.
The researchers believe that the cheap apparatus will aid in purifying wastewater .Usually, companies work to evaporate water from wastewater ponds to concentrate and get rid of the contaminants. A cheap solar sponge may as well boost the cleanup.
To be helpful for desalination or other drinking water applications, the device requires another plastic or glass layer on top to amass the water vapor. This might enhance the system’s competence by trapping more heat and boosting evaporation, according to the researchers.