Water crisis is one problem that is affecting people world over. Us humans are the sole reason for this problem because human have misused water resources, and polluted many to the core that they are no more fit for human drinking and other purposes. If this reckless behavior continues, it would not be long that almost every part of this earth faces draught like condition. The need of the hour is to mend such reckless behavior and come up with solutions that make clean water available for humans. One such way out is desalination.
Our planet has no dearth of water resources but 96.5 percent of all the water on earth is present in oceans, which is salt water. We all know that humans cannot consume seawater because of its salt content, as it dehydrates human body. They cannot even use it for other purposes like irrigation. Such massive amount of water in oceans is of no help for humans. However, things have changed now, in fact, it would not be wrong if we say that scarcity has made human beings to think and come up with several ideas that can turn the saline ocean water fit for human consumption.
Desalination is a process that takes away salt from saline water and leaves it tasting like fresh water. Numerous desalination technologies like RO (Reverse Osmosis), electro dialysis, distillation, and vacuum freezing came up but they happened to be much more energy consuming and expensive than other ways of deriving water like water recycling, taking out underground water, from rivers, and water conservation.
Desalination consumes too much energy
Everybody knew that oceans are a great source of water but despite having the hang of desalination technology; many nations were not using it because of its high-energy consumption and its expensive nature. A search for such a desalination system started that could turn ocean water into salt free water in a way that was not expensive and was eco-friendly. A system that was not very expensive money wise and energy consumption wise altogether. The search brought fruitful result in the form of solar powered desalination plants.
The technique to take away salt form ocean water with the help of sun energy is called the solar desalination. This technique is quite effective and is eco-friendly as well. The project uses sun energy to purify water, and this technique has two forms – direct and indirect.
Direct Solar Desalination
This technique is employed in numerous desalination plants and marine survival kits contain this mechanism. A simple cycle makes use of a solar collector and a distilling mechanism. This technique is proportional to the solar surface area and the incidence angle. Direct solar desalination plants are in very good interest of plants that have a production capacity of less than 200m3/d.
Indirect Solar Desalination
This technique employs two separate systems – conventional desalination plant and a solar collection array (photovoltaic or fluid based thermal collectors). Indirect solar desalination projects that use PV (photovoltaic) panels and RO (Reverse Osmosis) have been in commercial use for some years now. The higher the efficiency of the plant, the higher is the clean water production through an indirect solar desalination technique. RO, Stage Flash Distillation (MSF), Multiple Effect Distillation (MED), Humidification Dehumidification (HDH), and the Freeze Effect Distillation are some methods used in the indirect technique.
Desalination is a process that makes salty ocean water fit for human consumption. However, not all desalination projects and plants are green but the ones that use solar energy for their operation. They are clean and green projects and are affordable too.