Turning Fog into Drinking Water

We’ve written before about Star Wars-like technology that can pull water from the air. Now a team of MIT and Chilean scientists have found a way to efficiently harvest fog.

The technique is based on plants and bugs that rely on air-borne water for their hydration needs. In most cases, these plants and bugs rely on a solid surface that collects droplets of water from the fog. The researchers have found a way to employ a large screen made of fine mesh coated in a special chemical that causes the water to condense on the screen’s surface, the drip down into a trough that funnels the water into a collection device. The mesh is created out of tightly woven stainless-steel filaments that are just slightly thicker than a human hair.

The breakthrough, the scientists say, is in the mesh. Apparently fog-harvesting is already in use in many nations around the world. But the scientists found that these systems aren’t very efficient because the size of the filaments — made of plastic — is too large to collect more than 2 percent of the available moisture. The new, specially coated stainless steel nets can collect more than 10 percent of the available water, the scientists say, and layering nets one behind the other can increase efficiency even more. One of the best things about the nets is that once they’re in place, they consume no energy and require only occasional cleaning to operate at peak efficiency.

The hope is that these nets can be manufactured and deployed on a large scale in semi-arid areas that receive little rainfall but are regularly shrouded in fog, providing a reliable source of potable water.

An article from MIT states that “Chilean investigators have estimated that if just 4 percent of the water contained in the fog could be captured, that would be sufficient to meet all of the water needs of that nation’s four northernmost regions.”

Maybe if the nets had been used on Tattoine, Luke Skywalker wouldn’t have complained so much to Uncle Owen about having to help with the harvest.