IISc Develops Novel Solar Powered Thermal Desalination System

Bengaluru’s Indian Institute of Science (IISc) has developed a solar energy based new thermal desalination system. The IISc researchers say it is energy-efficient, cost-effective and portable. These features make the solar thermal desalination system convenient for installation in remote areas that have no or limited electricity supplies providing clean drinking water to the inhabitants.

The solar powered desalination system was designed by Susmita Dash, Assistant Professor in the Department of Mechanical Engineering, and her PhD student Nabajit Deka.

IISc says that the thermal desalination is most employed for water desalination. In this process, first saline water is converted into vapour, which is free of the salt and minerals that are present in the water. This vapour is allowed to condense to forms clean drinking water. The entire process needs a lots of energy.

The IISc said in its official statement, “Thermal desalination systems work by heating saltwater and then condensing the resulting vapour to obtain freshwater. But the energy required for evaporation is usually obtained from either electricity or combustion of fossil fuels. An environment-friendly alternative is using solar stills in which solar energy is employed to evaporate saltwater in large reservoirs and the vapour that condenses on a transparent roof is collected.”

Susmita Dash added that as an alternative to solar stills, the IISc researchers have a developed a novel design for areas having limited electricity supply. The thermal desalination system comprises a reservoir of saline water, an evaporator, and a condenser enclosed within an insulating chamber to avoid heat losses to the ambient air.

The IISC researchers maintain that the solar powered desalination system can also clean brackish water and groundwater water that contains dissolved salts. The system can automatically adjusted shifting positions of the sun in the day. The institute said that they want the desalination system to be deployed for domestic and commercial uses. Hence, it will scale it up in terms of durability and volume of fresh water production.

Recently, Massachusetts Institute of Technology (MIT) invented a passive solar evaporation system to clean saline water and waste water to help communities to have access to drinkable water at a cost of just $4.