A team led by US architect David Hertz has developed an energy-efficient technology for harvesting fresh drinking water from the air, which is contained within a shipping container for easy transport.

The WEDEW system, can generate 2,000 litres of water per day by combining cold and hot air to create condensation, in a manner that replicates the way clouds are formed.

Created by US partnership the Skysource/Skywater Alliance, it was the winner of the recent Water Abundance XPRIZE. This two-year development competition aimed to find the best system of atmospheric water generation (AWG) – a process where water is drawn out of the air via condensation.

AWG can be used to help areas where water scarcity or quality are a problem. However, existing technologies have come with a high carbon footprint. The Water Abundance XPRIZE was set up to reward an energy-efficient demonstration of the method.

Competitors had to extract a minimum of 2,000 litres of water per day from the atmosphere using 100 per cent renewable energy, at a cost of no more than two cents per litre.

Skysource/Skywater Alliance's winning entry, WEDEW (it stands for wood-to-energy deployed emergency water), not only has its own 100 per cent renewable energy source, it is carbon-negative — meaning it generates extra energy that can be used by the local community. The WEDEW units are said to work in any climate.

"More fresh water exists in the atmosphere than all the rivers on earth, yet we haven't tapped into this vast supply," said the Skysource/Skywater Alliance, whose AWG process starts with biomass gasification, or the burning of plant matter, a renewable energy source.

"Reflecting principles from nature, the two technologies of biogasification and water generation are co-located and engineered into a performative symbiosis, a four elemental solution in which earth + fire + air = water," continued the company.

The process generates power as well as hot humid air for water generation. Another beneficial byproduct is biochar — charcoal that can be mixed with soil for fertiliser. This is a stable, sequestered form of carbon with agricultural benefits.

"Biomass is a natural part of the carbon cycle, the global process by which carbon flows between the atmosphere, oceans, land and living organisms," said the Skysource / Skywater Alliance. "Human activity has thrown this cycle out of balance by releasing excessive amounts of carbon into the air."

"The waste products of forestry, agriculture, and natural disasters contribute to the buildup of atmospheric greenhouse gases. Instead, biomass can be alternatively used as a renewable fuel source for gasification."

The California-based Skysource/Skywater Alliance was founded by Hertz — who has his own practice, the Studio of Environmental Architecture — and photographer Laura Hertz. It builds on the patented Skywater technology developed by Richard Groden.

A number of groups are working on harvesting drinking water from the air. SunGlacier's solar-powered Desert Twins harvester can collect water in the hottest and driest of environments, while Arturo Vittori gave his Warka Water atmospheric water generator an architectural expression.