New technology produces water from the air
A new system developed by the University Centre of Energy Efficient Buildings and the Faculty of Mechanical Engineering of the Czech Technical University in Prague can be used in desert conditions to acquire water from the air. The system will be deployed in practice in the Czech pavilion at the EXPO 2020
Adevice that can transform the dry desert into an oasis through targeted microorganism reproduction may sound a little bit like a sci-fi story. The Solar Air Water Earth Resource (S.A.W.E.R.) is composed of two systems, one for extracting water out of the desert air and the other for cultivating the desert into fertile land.
The system for the acquisition of water from the air, developed by the University Center of Energy Efficient Buildings and the Faculty of Mechanical Engineering of the Czech Technical University in Prague, is used as a two-stage system in which ta desiccant – a material that binds water to itself through adsorption- is used in the first stage.
The desiccant removes the water contained in the outside air and holds it on its surface. The dehumidified air is then taken back outside. At the same time, additional desert air with its natural water content is taken from the outside and heated up to the point, where the water vapour stuck on the surface desiccant is released into the desert air and humidifies it. That is because the heated air can bind a larger amount of water vapour.
In simple terms, the Solar Air Water Earth Resource (S.A.W.E.R.) system produces water using only sunlight and air.
There are other technologies that use air humidity to produce water, but S.A.W.E.R. is different because it only requires solar energy. There is no need for a generator or a connection to the electricity grid – this system is fully autonomous.
The second difference is that the system could be used to produce water in the driest areas on Earth, and it could do so more efficiently than its competitors. In such regions, standard condensing units produce almost no water.
“Our aim is to produce water in areas where there is no infrastructure – no pipelines. S.A.W.E.R. could support human settlements or agriculture in areas where neither is not currently possible. Our technology could also be used as an emergency water supply, or to supplement existing infrastructure in areas where water is scarce,” says Jakub Dytrich, Chief Financial Officer, University Centre for Energy Efficient Building, Czech Technical University in Prague.
The advantage of S.A.W.E.R. is that you can transport the container to a remote area, either by truck or helicopter, and it will be operational within 24 hours of unloading. Just leave the unit running and it will continue to produce water, which you might use for agriculture or even to give your camels a drink. If you have internet connectivity, you can monitor how much water is stored in the unit and in any additional tanks. When deployed in the desert, S.A.W.E.R. will offer a well than never runs dry.
There is no need to connect S.A.W.E.R. to the local grid because it produces its own energy through PV/PVT panels. The technology is not energy intensive – it differs so much from desalination plants that it is hard to compare the two.
“However, we are not in competition with desalination plants,” says Dytrich. “We have no plans to develop a large machine capable of producing the quantity water needed to meet demand in a large city such as Dubai. S.A.W.E.R. is best placed to serve remote areas with no pipelines or access to seawater – places where there is no water at all, or where it has to be delivered by truck. In locations where it is feasible, desalination is more effective, both in terms of investment costs and the amount of water produced.”
In as far as the cost is concerned in comparison to desalination plants, Dytrich says that desalination plants require far greater investment because they are larger and produce much more water than the S.A.W.E.R technology. They also have far higher operational costs.
“Our units are powered by sunlight; the only other resources needed are the minerals required to make the water produced drinkable. The operational costs of S.A.W.E.R. are almost zero – you just need to maintain the unit and change its filters from time to time,” Dytrich points out.
“S.A.W.E.R. technology is not expensive for places where water has to be brought in by helicopter. It is cheap for areas that have no other means of acquiring water,” says Jiří František Potužník, Commissioner General, Czech Pavilion at Expo 2020 Dubai. “For some time, the cost of creating a litre of water through this technology will undoubtedly be greater than through desalination plants, but the cost of operating the S.A.W.E.R. systems themselves is comparable or cheaper.
“This technology does not need electricity because it makes its own. Nor does it require constant attention as it is fully autonomous.
“I would immodestly compare the S.A.W.E.R. system to the steam engine. It is the first of its kind, and it works. Now, it will grow and develop, and I hope it will not only increase its effectiveness but also reduce its cost.
To date, S.A.W.E.R. has only been tested in laboratory conditions. Its developers are currently finalising a container version of the technology, and preparing to ship it to the Middle East so that it can be tested under real-life conditions in Sweihan, Dubai.
Based on existing test results, the technology is expected to be applied at utility scale in 2020. A formal introduction of S.A.W.E.R. will be made at Expo 2020 Dubai, but in the meantime, its developers will work to identify a partner that can manufacture the first series of units.
“Currently, we have a functional mobile prototype, which we will test in Dubai, deep in the dry desert. Even now, I am convinced that the main commercial use of S.A.W.E.R. will be in areas that have no other means of getting water, either because they inaccessible by road or too remote,” says Potužník.
“Whether in the mountains or in the desert, imagine a route through a waterless environment that features a chain of oases created by mobile S.A.W.E.R. units, which continuously create water that can be stored in underground reservoirs, or used to water their surrounding area.”
The S.A.W.E.R. system started by making distilled water, which is ideal for storage and filtration. “Last autumn, the team connected it to a mineralisation unit, called WatiMin, which turns the water it produces into potable water. I drank it together with our partners from the UAE, and we all enjoyed it,” says Potužník.
“In the same manner, we can take water made from the air and modify it in photobioreactors, thus turning it into nutritious irrigation material for the cultivation of the desert. To this end, a team of Czech botanists have also used subsurface fungi to preserve the water and its nutrients for the roots of plants.
“This technique has been successfully tested, and we are developing it further as we speak. The tests that we intend to conduct in the real-life conditions of Dubai will allow us to see how the equipment responds to fine desert sand.”
Potužník says that the team wants to further the effectiveness of the S.A.W.E.R. system by making it cheaper, and by adapting it to various conditions and types of use. “However, there is one thing I haven’t mentioned: this system is an illustration of the exceptional potential of Czech universities and scientific institutions so, in my opinion, the biggest challenge we face is friendly competition from the other participants at Expo 2020 Dubai,” says Potužník.
On why the developers chose Expo 2020 Dubai as the platform to showcase the S.A.W.E.R. technology, Potužník says that he was looking for a way to take as many Czech inventions and innovations as possible, and connect them with Expo 2020 Dubai’s theme of ‘Connecting Minds, Creating the Future’. There are five such inventions in the S.A.W.E.R. system alone, he says.
“Secondly, the UAE is a country that is showing the world how to use natural resources, which are always limited, through its sustainable development. This is only possible through education and research, and Czech universities and research institutions have the potential to support both,” says Potužník.
“Thirdly, the beautiful, dry deserts of Dubai inspired me to think of a technological wonder – to create a life-giving oasis by creating water solely from the sun and the air. This technology could help to combat droughts all over the world.”