Mesh draws water from the sky

April 24th, 2017 / By: / What's New?

Photo: © Dar Si Hmad
Photo: © Dar Si Hmad

UN-Water, the United Nations’ water agency, estimates that by 2025, 1.8 billion people will be affected by water scarcity, according to an article in Smithsonian magazine. The article says that scarcity disproportionately affects women and girls, who in many regions are responsible for finding water—often for hours each day. A series of mesh fog collectors may be the answer for regions where water is scarce but clouds are not.

CloudFisher is one of the latest devices to harvest water from clouds. CloudFisher mesh “billboards” are currently stationed on Mount Boutmezguida in southwest Morocco, with a plan to increase the number of billboards to help meet resident’s potable water needs in the future.

Currently, the CloudFisher system can provide each of the thousand or so people in the area about 18 liters of drinking water per day. Whatever is left over would be designated for livestock and crops. This is more than double the previous supply of eight liters per day, stated Peter Trautwein, CEO of Aqualonis, who designed CloudFisher.

Collecting drinking water in fog collection systems seems simple: Mesh is strung between poles on rectangular or cylindrical stands. Minute droplets of fog condense in the tiny holes of the mesh and come together into larger drops that travel down the mesh fibers. A trough along the bottom of the device catches the water, which is then collected in a tank.

For the Morrocan project, however, CloudFisher had to handle the complexity of high winds. The company designed a buttressed mesh billboard with a 3-D pattern of fibers intertwined in a netting and reinforced by a thicker plastic “skeleton” grid. That way the mesh doesn’t act like a sail and lose water to the wind.

Aqualonis reports that the first test phase showed that woven mesh produces a lower water yield than monofilaments. The three meshes with the lowest yields (slubbed fabric, Raschel net and shade fabric) were replaced in the second phase with two new fabrics (mosquitera and antigranizio). The last free field in the CloudFisher was equipped with two hail nets set 115 millimeters apart. The fog is caught in the front dual-layer net, and the rear single-layer net catches the drops of water blown out of the front net by the wind. This increases the yield.

Smithsonian reports that many designs are currently in development and competition in the field is growing. Some designers are experimenting with coating the mesh; others are looking at biomimicry of plants, insects and birds.

The Moroccan project is an international collaboration among the nongovernmental organization Dar Si Hmad and several German organizations, including CloudFisher’s parent company Aqualonis.  Aqualonis GmbH, based in Munich, is a licensee of the Water Foundation and markets and sells the CloudFisher fog water collection technology worldwide.