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In August, the team of the CTU University Centre for Energy Efficient Buildings put the S.A.W.E.R. system installed in the Czech National Pavilion at EXPO 2020, which will be held from 1 October 2021 to 31 March 2022, into permanent operation. The process of its technical integration and commissioning was completed one month before the opening of the gates of the world exhibition to the public.

Triuimph at the Dubai expo
S.A.W.E.R. technology is an indispensable part of the Czech stand at EXPO 2020, the central theme of which is the extraction of water from the air and its use for dry desert cultivation. Scientists from the UCEEB CTU have connected the entire system with the technical facilities of the pavilion, which is currently being completed.
Among other things, the Solar Air Water Earth Resource (S.A.W.E.R.) system, which produces water from the air using solar energy, will be on display throughout the exhibition. According to Jiří František Potužník, Commissioner General of the Czech Republic's participation in the exhibition, the system is also attracting interest from outside the United Arab Emirates, such as Riyadh and Malaysia.
Czech Foreign Minister Kulhánek said he is most excited about the S.A.W.E.R. system and considers it the highlight of the exhibition. "This is really something fascinating. It shows how advanced technology the Czech Republic is capable of producing," the minister said.
The exhibition was supposed to be held last year but was postponed due to the covid-19 pandemic.

Unique technology
The S.A.W.E.R. device, which can turn a dry desert into an oasis through targeted reproduction of microorganisms, may seem a bit like science fiction. But the research and development relies in part on the science fiction genre to point to the technologies of the future. The Solar Air Water Earth Resource (S.A.W.E.R.) consists of two systems, one to extract water from desert air and the other to cultivate the desert into fertile soil.
The system for extracting water from the air, which is being developed by the University Centre for 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 a desiccant - a material that binds water vapour to its surface by adsorption - is used in the first stage. This removes the water content from the outside air and holds it on its surface.
The dehumidified air is drawn back outdoors. At the same time, additional outdoor air with its natural water vapour content is drawn into the system, which is first heated to such a high temperature that the water vapour can be released from the surface of the desiccant, thereby humidifying the desert air. This is because air at elevated temperatures can bind more water vapour. The cooler then receives significantly more humid air than the outside desert air. This allows the cooler to extract much more water by condensation from the air.

Further developments
Whereas a conventional cooler can extract an average of 10 l/day from desert air, the S.A.W.E.R. can extract up to 200 l/day at comparable treated air flows. The main feature of the S.A.W.E.R. system is its autonomous operation. The energy needs of the system are fully covered by solar energy (solar photothermal collectors, photovoltaic modules, heat and electricity storage). A by-product of the technological system is hot water for showering and cool air for building air conditioning.
The system already produces water for subsurface watering of the garden and the first results from operation show that it can supply more than 800 litres of water per day in summer. In addition, it will preheat the water with waste heat when the kitchen needs it.
In addition to the S.A.W.E.R. and MAGDA technology, UCEEB scientists are preparing a patented additional prototype device called the "Field Bottle" that extracts water from the desert air and is portable on the user's body. The Field Bottle will produce up to 2.5 liters of water per day (depending on climate conditions).

S.A.W.E.R.: Česká technologie získávání vody ze vzduchu s využitím solární energie běží v Dubaji naplno -