Direct Absorption Solar Collectors (DASCs) are devices that employ a special heat transfer medium acting as a direct radiation absorber, in order to obtain a "volumetric" thermal conversion. Due to their interesting thermodynamic and optical properties, nanofluids (NFs) have been proposed as a vector for this particular process. We will talk about the potential of nanofluids in thermal solar applications, and how to solve their stability and compatibility issues, with Dr. Arianna Berto of the University of Padova