In many parts of the world, including California, South Australia, Qatar, among others, desalination of sea water is a practice, without which the intensity of drought and lack of drinking water would have had an even more devastating impact than what they have now.
However, the huge amount of energy that is consumed by desalination plants, the harmful salty sludge byproduct and the risk to aquatic life, have prevented the process of being labeled anything close to green. Now, projects around the world are looking into integrating solar power into the desalination system, hoping to tackle at least one of the above listed problems.
One initiative is taken by WaterFX, a start-up based in California who are looking into greening up the desalination process. They promise that if their idea is realized, they will not only be generating renewable energy to run the plant, but they might well resolve the problem with lack of fresh water resources, and not only in California.
The system that they present uses concentrated solar steel. It removes salts from the water by collecting the energy from the sun, which powers a heat pump. The heat is used to enable evaporation of fresh water, which is let to condensate and then collected as pure water. There is also a storage system, which holds any extra heat as back up in case it is needed when the sun is not strong enough.
This is not the first project of this kind. In Soudi Arabia, the plans to construct such solar powered desalination plant have been discussed for quite some time now. The main benefit of such technology there would be that currently, per day, the country uses as much as 300,000 barrels of crude oil only to extract fresh water from the sea. Even if this was the only place on Earth where such initiative is undertaken, it would already contribute greatly to the fight against excess greenhouse gas emissions. The best part is, there are others- in South Australia, in Qatar, and hopefully soon in many other parts of the world where fossils need to be replaced by renewables so that the precious resource is extracted in the greenest way possible.
Image (c) WaterFX