Enhancement of Atmospheric Water Generator performance by exploiting historical underground spaces

Many Mediterranean countries are facing a severe water crisis due to climate change both in Southern Europe, Northern Africa and Middle East. One possible solution to mitigate this problem could be the use of cooled Atmospheric Water Generators (AWGs), devices available on the market that can condense the humidity present in the air. AWGs use a simple refrigeration cycle where the humid air mixture reaches dew point temperature, causing the vapor contained within it to condense. The main problem is that in arid or semi-arid areas, where water is most needed, they require huge energy amounts to operate. Such requirement can be mitigated by exploiting the natural insulation phenomenon of the subsoil, which is commonly used for shallow geothermal systems for heating and cooling. The drawback in this case are the drilling, excavations and installation costs. The present study investigates the opportunity of using some historical underground spaces, wells, shafts and tunnels already in the Mediterranean area territory, for boosting the efficiency of AWGs, to fight water shortages in the Mediterranean area.