Home water harvesting is being supercharged by Nobel Prize-winning tech
Start-up Ahbstra applies MOF technology to draw moisture from the atmosphere at volume, using minimal energy
At tech start-up Ahbstra’s low-key workshop in London’s Chelsea Wharf, a maze of rotating drums, heaters, fans and electrical boxes sits atop a large workbench. At the end of this whirring matrix is a tap. From it flows water drawn from the air.
It’s a test unit, a proof of concept in the UK company’s mission to turn desert air into drinkable water. Ahbstra’s Ark water generator is able to harvest up to 508 litres a day of water from the atmosphere — more than enough for a four-person household in the UK, and enough for one individual in the driest places, such as the UAE. It officially launches in Barcelona today.
On the outside, Ark is a sleek modern arrangement of weather-resistant aluminium slats. Ahbstra founder and chief executive Hashem Arouzi believes that, despite it being the size of a shipping container, Ark is chic enough for private homeowners not to want to hide it away.
He and his team hope that it will change the housebuilding landscape for architects, property developers and homeowners. It’s early days. First buyers, including Ibizan restaurant Jondal, the architect, technologist and impact investor Thomas Ermacora and investor-entrepreneur Max Gottschalk, have paid about £150,000 for a unit. The hope is that with successive rounds of funding and development, Ark will segue from being a luxury offering to something more accessible and affordable. Five-year sales targets are for more than 1,000 a year and with them, the tech company expects the price to come down “significantly” as production scales up, “just as we have seen with EVs, home batteries and solar”, says Arouzi.
Drawing moisture from the air is hardly a new concept. Aircon units, dehumidifiers and current “dew-point” systems based on cooling coils all do this. But Ahbstra’s point of difference is the greater volume of water it is able to harvest, using less power. Tests in Arizona show that 384 per cent more water was harvested using 0.7kW/h compared with 1kW/h by a dew-point system.
Ahbstra says its power lies in its use of metal-organic frameworks (MOFs) — cutting-edge nano materials with a huge internal surface area which can, among a range of abilities, extract water from the air even at 10 per cent humidity, promises the company. Pioneering research into this “new form of molecular architecture”, sometimes described as molecular Lego, won a trio of scientists the Nobel Prize last year.
Arouzi and chief technology officer Richard Perkin explain how particle reactors within Ark’s eight drums cycle air through the MOFs to maximise performance and increase harvesting capabilities; four drums extract water, while the other four capture it. (The drums will need to be swapped out every five years of Ark’s 15-year lifespan, for a service fee, and the MOF granules reprocessed.) Ahbstra worked with the Capgemini-owned tech development firm Cambridge Consultants to scale up the machine.
This is a nascent field; Ahbstra believes Ark is the first commercially available MOF-based water-harvesting solution on this scale — the only plug-and-play system on the market. Yet dozens of companies are in the race to monetise MOF tech. Atoco, founded by Omar Yaghi, one of the Nobel winners, is exploring using waste heat from data centres to harvest water. It is also testing MOFs in both on and off-grid systems (such as those using dedicated solar power sources).
Kaveh Madani, director of the UN University Institute for Water, Environment and Health, who helped define the term “water bankruptcy”, says such “technologies are scientifically exciting”. He envisages take-up “in specific settings, such as remote homes, emergency response, humanitarian operations, island communities or places where conventional [water] supply is unreliable or environmentally damaging”.
Unlike Atoco’s products, Ark is not built to run exclusively on solar power. To produce 500 litres, it requires about 10kW of power, about the amount used a day by a large household. Ahbstra says a combination of solar and grid supply would be “the ideal set-up”. With ongoing hardware improvements, it aims to lower Ark’s energy consumption by 20 per cent. “We know energy usage is a massive customer consideration and we’re striving to reduce it,” says Perkin.
Arouzi was initially inspired to pursue the project after a well on his Ibiza property dried up. On the White Isle, Ahbstra research shows that 15,000 homes rely solely on wells or water delivered by trucks. Ark, he hopes, can help to future-proof private properties — making them more resilient to climate change.
But water harvesting tech is no silver bullet, warns Madani. In a world of increasing water scarcity, and using more than we can replace, it will be merely part of a suite of solutions. “It is not a substitute for living within water limits,” says Madani, who has extensively researched ancient systems, including Iran’s qanat underground water supply channels. Updating these is also vital.
The World Monuments Fund helps to restore and repair ancient water systems, from Tunis’s majels (cisterns under the city’s courtyards) to India and Nepal’s complex networks. The old ways “have been tried and tested, yet we often dismiss them”, says John Darlington, WMF director of projects for Britain. An increase in housing and other development “has not been matched by an increase in infrastructure”, he adds. “It is easy to forget the lessons of the past. But we shouldn’t.”
As Ahbstra enters the fray it is planning its first major funding round, targeting institutional investors including venture capitalists. “Ultimately, we hope to be a more mass-market brand,” says Arouzi. There’s a long way to go from a £150,000 price tag. But they are in the flow.
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