Fog Collectors Help Boost Water Supply in Arid Regions

For people living in parts of the world where hydration isn’t a problem (I’m looking at you, my friends in the Pacific Northwest), it probably seems weird that fog can be one person’s dismal weather condition and another person’s valuable, life-saving commodity. But in regions of vast, arid desolation like the Namib Desert in Africa, where more water rolls in from the Atlantic Ocean as fog than falls as rain, you’ve got to take moisture any way that you can get it. But how can you turn humidity floating around in thin air into a viable water supply?

Area native, the Namib beetle (Stenocara gracilipes), has survived here in the world’s oldest desert for longer than human memory (or, possibly, humans) by collecting drops of water from the morning fog, storing them on its back (with bumpy adaptations suited for this purpose), and drinking from this reserve over the course of the day like a beer-hat-wearing football fan at the stadium on any given… day of the week. Massachusetts Institute of Technology (MIT) scientists have taken this cue from nature to inspire improvement of fog collectors that attract and accumulate moisture to supplement places not gifted with an abundant water supply of their own.

CC licensed Flickr photo shared by vige

According to the WHO (World Health Organization) and UNICEF (United Nations International Children’s Emergency Fund), about 900 million people live in such areas, and many among them are forced to travel miles each day just to secure enough of a water supply to survive. But there’s more to the equation than mere survival. Those of us lucky enough to live in parts of the world where access to a steady water supply is something we take for granted may not even realize how much of a drain on a region’s productivity this can be, which serves to perpetuate the state of so-called “third world” nations. Says MIT’s Legatum Center for Development and Entrepreneurship director Iqbal Z. Quadir: “About one-third of the planet’s water that is not saline happens to be in the air. Collecting water from thin air solves several problems, including transportation. If people do not spend time fetching water, they can be productively employed in other things which gives rise to an ability to pay. Thus, if this technology is sufficiently advanced and a meaningful amount of water can be captured, it could be commercially viable some day.”

While the Namib beetle is able to gather up just enough water for its own tiny, selfish purposes, the MIT scientists are trying to make some adaptations of their own to the beetle’s design that would maximize the efficiency of fog collectors and be of sufficient value to any water supply they supplement. Rather than relying on a hard surface like the Namib beetle’s shell (which sheds more water than desired due to its impermeable nature), scientists have found that mesh is far better suited to this goal. “We tried to replicate what the beetle has, but found this kind of open permeable surface is better,” says MIT’s Shreerang Chhatre. “The beetle only needs to drink a few micro-liters of water. We want to capture as large a quantity as possible.”

Current fog collectors are only able to harvest about one liter of water per square meter of mesh on a daily basis, which is admittedly a trifling drop in any water supply’s bucket. But Melissa Rosato from the nonprofit Canadian enterprise FogQuest says that improvement to fog collectors is ultimately a problem that goes beyond technology. “You have to get the local community to participate from the beginning,” Rosato says. “They’re the ones who are going to be managing and maintaining the equipment.” Getting developed communities on board with the benefits offered by fog collectors to enhance their water supplies could help boost development, as well. Says FogQuest’s executive director Robert Schemenauer: “As the number of people and businesses in the world increases and rainfall stays the same, more people will be looking for alternatives.” Even in places currently perceived as comparatively prosperous to the Namib Desert — take California, for instance — a dwindling water supply may someday depend on fog collectors to keep the landscape and its population sufficiently quenched.