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The University Centre for Energy Efficient Buildings (UCEEB) of CTU has invented a technology to get water even from desert air.

But they can also "squeeze" energy from the sun, earth or fire.
The UCEEB building in Bustehrad, where the S.A.W.E.R. technology was developed, hosts a number of cutting-edge laboratories. Photo: UCEEB
The desert is usually considered a dead, lifeless area but it is enough just to water it and it turns into a flourishing oasis. The life-giving water may come not only from wells or irrigation canals but paradoxically also from the extremely dry surrounding air. This is demonstrated by the S.A.W.E.R. (Solar Air Water Earth Resources) technology developed by UCEEB in cooperation with the Faculty of Mechanical Engineering of the Czech Technical University at its research base in Bustehrad. The extraction of water from the air is not revolutionary and many devices work on the principle of condensation but not in a desert environment with humidity that drops below five grams of water per kilogram of air. However, experts from CTU have found a way to "squeeze" even this air. They have used the physical process of sorption, whereby the air moisture is first accumulated, then released by heat and finally precipitated on a cooler.
The development of the S.A.W.E.R. device began in Buštěhrad four years ago and in 2019 a prototype was tested in the Sweihan desert in the United Arab Emirates, when this first prototype of the Czech invention was able to produce 100 litres of water per day. The S.A.W.E.R. consists of two containers, one of which contains the sorption unit itself and the water storage tank, while the other, the energy box, contains the battery storage and the storage space for the solar collectors. In fact, a solar roof made of photovoltaic panels is developed over both containers during operation. This makes it possible to create an autonomous system that is not dependent on any energy supply.
SAWER. is already working in the Czech pavilion in Dubai - albeit a more elegant solution that dispenses with containers. The Dubai "air wringer" will be connected to a photobioreactor from the Botanical Institute of the Academy of Sciences of the Czech Republic, which cultivates microalgae, mixes them with water and then brings the garden around the Czech pavilion to life in the form of subsurface watering. The second finesse that S.A.W.E.R. will present at EXPO is the connection with the WatiMin mineralization unit from EuroClean. This turns irrigation water into drinking water that can be tapped directly into a glass.
Although in Dubai itself, where the climate is humid, S.A.W.E.R. is unable to fully demonstrate its capabilities, it was clear even before the EXPO gates opened that the exhibition generator alone was not sufficient. The originally planned capacity of 500 litres per day was not enough to irrigate the garden, so the maximum capacity of the "exhibition" generator was increased to 800 litres.
The desert air water maker was tested in Sweihan in the United Arab Emirates. Photo: UCEEB
In parallel with the S.A.W.E.R. technology, Bustehrad is also working on its smaller sister which has been named MAGDA (from the English words Mobile Autonomous water Generator from Desert Air). It works on a similar physical principle to its larger, containerised brother. The difference is that it is two boxes on wheels that can be loaded onto the back of a pick-up truck. The smaller size is matched by the daily production which could be around 10 litres of drinking water. But MAGDA is not the last of a series of "air wringers" being developed in Bustehrad. The smallest addition is a device with the working name "Čutora". A field bottle connected to a photovoltaic sail, which is heading for the prototype stage, could produce enough water for one person - perhaps a soldier in the desert.
"It turns out that the demands of potential customers run in two directions. In the case of the S.A.W.E.R. technology, they would like more daily water production but there is also demand for smaller, mobile solutions. So we are going down the path of increasing production but also smaller portable devices," explains Robert Jára, Director of UCEEB. According to him, both S.A.W.E.R. and MAGDA have "suitors" and not only from Czech companies. In addition to the Emirates, Saudi Arabia, Singapore, Malaysia and Australia also look promising. However they left nothing to chance in Bustehrad and they insured the uniqueness of their water producers. S.A.W.E.R. has Czech, Australian and American patents, an Israeli patent is pending and a patent from the Gulf Cooperation Council (GCC) is also pending. Its sister MAGDA is patented in the Czech Republic. In Australia and Israel, a proposal has been filed to extend patent protection. The aforementioned "field bottle" should soon receive a domestic patent. Of course, it is unrealistic that the UCEEB laboratories in Bustehrad would turn into a factory and become a production base. "We want to go down the route of licensed production from which we will receive royalties," says Robert Jára.
SAWER. is by far the most famous invention of the UCEEB but it would be a shame to associate the Bustehrad experimental base of the CTU only with this desert water producer. Inside the building, by the way the largest wooden building in Central Europe, there are a number of laboratories that contribute significantly to the efficient use of elements other than water. "Our artificial sun is able to simulate different intensities of natural light and we test photovoltaic panels and entire assemblies here. We also had an aircraft wing here where we tested how it would behave if it had a surface colour other than white or grey," explains Robert Jara.
A few doors away, the WAVE microelectric power plant was being built, it supplies electricity and heat completely self-sufficiently, independently of the distribution network. The basis is a wood pellet boiler, but inferior wood chips can also be used as an energy source. The micro-power plant is also an almost textbook example of how to turn an original dissertation into a finished product and then send it out into the world. Since 2019, WAVE has been operating as a reference project in Mikolajice in the Opava region, with additional technology installed in Písek. A student startup was created because of the micro-power plant, and today the technology is already being offered under license by a private company under the slogan "The only boiler that makes money".
Although the UCEEB building in Bustehrad was built seven years ago, it still offers a high standard for work and a place for employees to spend time with colleagues. It is located on the site of the former brownfield of Třinec Ironworks which has its advantages. There is plenty of space in the surrounding area and individual projects can naturally expand outside the building itself. As part of the experimental prefabricated apartment buildings on which UCEEB cooperated with the RD Rýmařov construction company, there is also a house with several apartment units which meets very high energy standards is located in Buštěhrad. And right next door, a plot of land has already been prepared for the Czech team training for the Solar Decathlon competition which will take place next year in Wuppertal, Germany. The student decathlon team will build a house in Buštěhrad where they will practice disciplines such as sustainability, design and innovation.
In the end, it doesn't quite matter that the only UCEEB representative at EXPO 2020 in Dubai will be S.A.W.E.R. that is quite hidden in the interior of the Czech pavilion. A quick tour of the University Centre for Energy Efficient Buildings suggests that they already have their own little EXPO in Bustehrad.