Desalination offers a lot of promise to communities that may face water scarcity in the future. For some, the problem is compounded by the potential scarcity of reliable electricity. As such, it has been the aim of many researchers to develop solar-powered desalination devices, which is a difficult balance to strike.
However, a team of MIT researchers have recently developed a desalination system that is solar-powered and inexpensive.
Issues with desalination
A common problem in the development of desalination systems has been the accumulation of salt. This is particularly problematic when trying to make desalination systems function on solar energy. Previous attempts have used a special wick to absorb and filter saltwater through the device. These, though, accumulate salt and require a lot of cleaning.
The new MIT system is instead multilayered, using multiple panels to absorb heat and filter out potable water while transferring heat from one layer to the next above. This process has no accumulation of salt or brine.
Taking desalination to the next level
Additionally, the MIT system’s multiple levels greatly improve efficiency. It functions a lot like a liquor still. Basically, with each level added to a device of this design you improve energy efficiency.
“When you condense water, you release energy as heat,” said professor of mechanical engineering and department head, Evelyn Wang to MIT News. “If you have more than one stage, you can take advantage of that heat.”
A one-square-meter-sized version of this device could provide more than 1.5 gallons of drinking water per hour. It goes without saying that the energy costs in running a system like this would be minimal, as it is solar-powered. This system takes it a step further, though, with a version big enough to serve an average family’s potable water needs being able to be built for only around $100.
This innovation is also able to decontaminate other sources of dirty water. For communities in the developing world, MIT’s solar-powered desalination system is nothing short of a gamechanger.