GLOBAL CHALLENGES

Harvesting Water from the Air

Rebecca Kutzer-Rice | Date: 04-29-11 | Comments

Fog-harvesting devices bring clean water supplies to people in rural, arid areas. Now, a student at MIT has improved the technology behind these devices, which could soon be used worldwide.

While the world's water crisis is driving energy-efficient technologies, it's also encouraging new inventions for harvesting clean water. An innovative device from an MIT student could soon be used in water-starved areas to harvest liquid from fog.

Shreerang Chhatre, an MIT graduate student, was inspired by the African Namib Beetle, which lives in extreme desert conditions. The beetle's back collects droplets from the morning fog in a process that allows it to survive in the arid climate. For humans living in dry areas, a fog-harvesting device could allow locals to collect water at home, rather than travelling long distances to wells and streams.

The simple fog-harvesting device attracts fog with its mesh surface and then captures water droplets in a connected container. (Source: MIT)

According to the World Health Organization, as many as 900 million people worldwide lack access to safe drinking water. �As a middle-class person, I think it's terrible that the poor have to spend hours a day walking just to obtain a basic necessity,� Chhatre said. He hopes his device will be useful where he grew up, in the rural west coast of India, north of Mumbai.

The device attracts fog with a mesh panel, which connects to a water-collecting receptacle. �The technical component of my research is done,� Chhatre said. He is now outlining a business plan for implementing the device.

Engineers have been interested in fog harvesting since the 1990s, with the company FogQuest piloting projects in Chile and Guatemala. Chhatre's research has largely focused on improving the efficacy of past technologies.

The technology could also be useful in non-arid areas. Businesses and other organizations, for example, might harvest water from fog to reduce their environmental impact.

�As the number of people and businesses in the world increases and rainfall stays the same, more people will be looking for alternatives,� said Robert Schemenauer, the executive director of FogQuest, in a statement.

Chhatre is simultaneously earning a Ph.D. in chemical engineering from MIT and an MBA from the MIT Sloan School of Management. He is also a fellow at MIT's Legatum Center for Development and Entrepreneurship. According to MIT's Legatum Center, Chhatre's interest in water-related technology was a large reason why he was selected for this fellowship.

�We welcomed Shreerang as a Legatum fellow because it is an important problem to solve,� said Iqbal Z. Quadir, director of the Legatum Center. �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.
�Shreerang's project addresses multiple problems at the same time,� Quadir added. �After all, the water that fills our rivers and lakes comes from air.�