This scaled up test bed of NEWT’s direct solar desalination technology uses carbon black nanoparticles that convert as much as 80% of sunlight energy into heat. Results from an earlier prototype showed the technology could produce as much as six liters of freshwater per hour per square meter of solar membrane. (Photo by Jeff Fitlow/Rice University)
A team of U.S. researchers has developed an off-grid technology that uses solar energy alone to turn salt water into fresh drinking water, a solution it says could be a “game-changer” for an estimated 1 billion people who lack access to clean drinking water.
The Center for Nanotechnology Enabled Water Treatment (NEWT), a multi-institutional engineering research center based at Rice University, announced the development of its “nanophotonics-enabled solar membrane distillation” technology, or NESMD in the journal Proceedings of the National Academy of Sciences. The most significant application for this technology is providing clean drinking water to those without access to it. And since the system is modular and relatively portable, it can be taken to remote regions with little to no access to electricity.
The technique combines membrane-distillation method of water treatment with nanotechnology that turns sunlight into heat. By embedding sunlight-absorbing carbon black nanoparticles into the membrane, the researchers are able to harvest 80% of sunlight that comes in contact with the membrane. This results in faster water evaporation and a decrease in the amount of power the entire process needs.
“Unlike traditional membrane distillation, NESMD benefits from increasing efficiency with scale,” Naomi Halas, a corresponding author on the paper, said in a statement. “It requires minimal pumping energy for optimal distillate conversion, and there are a number of ways we can further optimize the technology to make it more productive and efficient.”