All You Wanted To Know About Solar Desalination

Solar energy has been found to be of immense use to mankind. Can you imagine a day or two if the sun does not shine? Isn’t it so depressing? Not only for our general well being, but solar energy is being immensely used for our huge growing power needs. Solar has found a large number of applications as the technology advances. Other than the many solar products available in the market today, the social impact of solar has increased manifold. For example, mini solar grids powering many rural parts of the world. Another growing application is in Solar Desalination of Water.

Solar Desalination is the technique to desalinate water using solar technology. The major advantage of using solar is that it is not only free but also environment-friendly. Solar energy is one of the most primitive ways used to desalinate water. It was used earlier to produce salt rather than drinking water. There are two types of Solar Desalination: i) Direct and ii) Indirect.

Image Credit: RE World

The demand for freshwater keeps multiplying with an ever-increasing growth in population, and the problem of scarcity of fresh drinking water is very grave. Many parts of the world still have no access to pure drinking water. According to statistics, at least 40% of the world’s population live without drinking water. As a result, people try and convert the available seawater into a usable form. However, desalination is a very power intensive process. Many countries desalinate seawater using fossil fuels which in turn leads to air pollution. It will be good for the environment if instead of using harmful fossil fuels, renewable sources of energy like solar could be used for the process.

Could you imagine the amount of power that is being used by the thousands of operating desalination plants in the world? If solar energy could be used at a large scale to power these plants, a large amount of carbon emissions could be prevented.

The cost of deploying solar energy at desalination plants is currently high. However, favorable policies could support its adoption, just like the way solar has been largely embraced by the world in the power industry. It has been found that CSP (concentrating solar power) is best suited for solar desalination process. There are three important components to be used – CSP, thermal energy storage and reverse osmosis.

One of the major concerns with solar power is its intermittency issue. Imagine what will happen to a plant running 100% on solar energy in the event of a cloudy day or at night time. If the plant keeps on turning off or on a layer of salt deposits on its membranes which further disturbs its efficient working. As a result, solar storage is an important component of this entire process. Reverse osmosis is favored because it is cost effective.

Solar energy seems to be a good option for desalination plants given growing energy costs, rising population and depleting water sources.