Scientists at Rice University have found a way to get fresh water from salt water using just solar energy. A federally funded research effort to revolutionize water treatment has yielded an off-grid technology that uses energy from sunlight alone to turn salt water into fresh drinking water.
The desalination system, which uses a combination of membrane distillation technology and light-harvesting nanophotonics, is the first major innovation from the Center for Nanotechnology Enabled Water Treatment (NEWT), a multi-institutional engineering research center based at Rice University.
This method is quite different to traditional methods. During conventional membrane distillation, hot, salty water flows across one side of a sheetlike membrane while cool, filtered water flows across the other.
The temperature difference then creates a difference in vapor pressure that drives water vapor from the heated side through the membrane toward the cooler, lower-pressure side. This off-grid technology is capable of providing sufficient clean water for family use in a compact footprint, and it can be scaled up to provide water for larger communities.