Hydro Harvest

Can you pluck fresh, clean drinking water out of thin air? The Water Abundance XPRIZE has shortlisted five companies that think they can.

After kicking off with the literal moonshot prize back in 2004, the XPRIZE foundation tries to solve global problems that industry sees no profit in. This year’s clean water challenge aims to supply the 2.1 billion people who currently lack safe drinkable water with a device that can 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 2 cents per litre.”


The overall goal is to replace costly desalination plants that produce CO2 and pump brine back into the seas – damaging the climate and the ecosystem. All equipment – including maintenance for 10 full years – has to cost less than $146,000.

The first round of testing took place in January with round two looming in July. The winner takes home is $1.5 million but each shortlisted team gets a share of $250,000. These are the companies trying to win the prize.

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Thin Air/Veragon

The Veragon & ThinAir Partnership


Four current and former Imperial College students founded Thin Air 18 months ago to solve the looming water crisis. The team took inspiration from the Namibian desert fogstand beetle which gathers minute water droplets from the air around hydrophilic bumps in its hardened wings then uses hydrophobic troughs to roll the water down to its mouth.

Thin Air’s paper thin composite membrane replicates this – condensing water 370 per cent more efficiently than other condensers according to CEO Jonathan Risley. For the XPrize, it has teamed up with Veragon – which supplies solar powered water condensers and, crucially, adds minerals.

“Most condensed water is just distilled water,” Risley explains. “You need the minerals for effective hydration.” The next step? Apply the surface to village billboards, house roofs and portable structures designed for refugees.

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JMCC Wing

JMCC WING


James McCanney, a nuclear physicist based in Hawaii uses commercially available atmospheric water generators powered by a high-efficiency, scalable wind energy harvester. “Wind is the only energy source that makes sense,” he explains. “It’s there day and night, even if it’s raining it’s still gathering energy so there’s less energy storage needed.”

His solution – redesigning wind turbines to maximise efficiency with a propeller blade shaped like an aeroplane wing. The far end of the closely pack wings have high tips to create a shroud on the outside that traps the wind and builds up tremendous pressure on the inside of the sail – which McCanney claims generates an additional 40 per cent of force. “The sail powers the water generator’s compressor and fan via direct drive,” McCanney explains. “It could be used anywhere, but the coasts of India and China would be the most effective.”

Uravu

Uravu

Uravu’s Indian team of architects and engineers set out to solve water shortages in urban centres using a patented hydroscopic material to collect water at night – then use solar collectors to heat, release and condense the liquid during the day.

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“It’s a passive process so there’s no need for any electricity, which is important for rural villages that have no power supply,” explains team leader Swapnil Shrivastav. “There will be a small fan to pass the air across the material, the solar panels can power that.” The team is also working on a version powered by low grade waste heat from buildings or small industrial plants. They say one panel can produce 15-20 litres of water per day – enough for a family of four to wash and cook.

Hydro Harvest

Hydro Harvest

Australia’s team is based at the University of Newcastle and has previous form in green solutions – professor Behdad Moghtaderi and assistant professor Elham Doroodchi invented Granex, an emission-free engine that takes heat from geothermal and industrial waste heat sources to convert into electricity.

Its XPrize nominated condensing box is filled with a granular desiccant that resembles the silica gel that ships with electronic items to keep them dry. Like Uravu, Hydro Harvest collects water at night and uses solar cells to heat and condense during the day. The system is designed to be modular – each box can provide 20 litres per day but stacking boxes can scale to supply the needs of light industry.

Skydra

Skydra

The three strong team behind Chicago-based Skydra – Jacques Laramie, Nathan Taylor, and Chris Wlezien – has adapted mass market heating, ventilation and air conditioning equipment (HVAC) to take advantage of such systems cooling and condensing properties.


As air passes over coils filled with cold refrigerant, water condenses out – typically seen as a waste problem for buildings with air conditioning, which have to dispose of up to 20 gallons of water per unit per day. The team has rearranged air flow through standard equipment but their special sauce is a new, renewable refrigerant which cools air at low electrical and environmental cost.

“The HVAC unit’s we’re using are cheap and widely available,” explains Laramie. “They can be bought or repaired almost everywhere in the world. Then we’re adapting natural airflow phenomenon to move the air across our refrigerant.”

Updated April 2, 2018: Correction: this article has been updated with the correct amount of prize money.