When we think of deserts, images of barren, sandy landscapes flood our imaginations. While deserts don’t have surface water, there’s still moisture traveling through the air above.
For some time people living in coastal desert areas have been using a rather low-tech solution to capture this moisture from the sky – a mesh net. As fog rolls in from the ocean it passes through mesh, which condenses the fog into droplets of water. The condensed droplets fall into collection bins and pool into reservoirs of clear, clear water.
Although traditional fog harvesting nets are effective, researchers at MIT in partnership with the Pontifical Catholic University in Santiago, Chile have created a new mesh material that can improve water collection by up to 10%.
According to the team, a fog harvester’s effectiveness is determined by threes things, i) the size of the material’s fibers, ii) the spaces between the mesh’s weave and iii) the chemical composition of the material itself.
The researchers found that the optimum configuration for a fog harvesting net was a “mesh made of stainless-steel filaments about three or four times the thickness of a human hair, and with a spacing of about twice that between fibers.” To enhance the harvester’s effectiveness the mesh is “dip-coated” in a solution that that makes it easier for droplets to slide into its collection gutter.
Currently, MIT researchers are testing their new harvesters in the Atacama Desert. Chilean experts say that if MIT’s harvesters work, only 4 percent of the water contained in the Atacama fog would be needed to irrigate the entire desert region, an area that encompasses 105,000 square kilometres (41,000 sq mi).
Images and Video Courtesy of Climate Prep & MIT