The S.A.W.E.R. container unit for producing water from dry air in a hot desert environment was commissioned in August of 2019 close to a camel farm near the city of Sweihan in United Arab Emirates. The team of the University Centre of Energy-Efficient Building and of the Faculty of Mechanical Engineering of CTU has been facing operational problems since the beginning; however, they managed to fix the problems gradually.
The operational issues of the system were caused by a faulty inverter that had to be replaced with a new one at the end of September. Since that time, S.A.W.E.R. has been working without any functional problems. Concerns related to container overheating and to negative impact on the battery repository and other electronics were not proven true. The UCEEB team is monitoring the whole device on-line in real time including the amount of water taken on the spot. Therefore, it is possible to watch the operation and to optimize the control strategies gradually in order to improve the efficiency and to ensure the production that is constantly over 100 liters per day.
At present, the system is producing between 75 and 110 liters of water per day; the fluctuation results primarily from low efficiency of use of night cooling (night emission of heat towards the sky) and from insufficient thermal use of solar energy by solar collectors that have not been vacuum-treated yet. Based on gradual evaluation of the operation, the research staff of UCEEB is acquiring valuable information for the improvement and simplification of other units. Sorption unit of the S.A.W.E.R. system that should be placed in the Czech pavilion at the EXPO 2020 fairground was designed and put to production at the same time that the operation analysis took place.
