The solar airplane "Interminatus" was built as a final project at Gymnasium Kirchenfeld Bern. The idea arose in February 2015, in August Interminatus had its maiden flight. The according paper can be found in Downloads (in German).
Since the end of the school project the plane has been refined: The solar panel was totally replaced by a new one. The recent flight test was successful. In the coming summer '17 Interminatus is supposed to take off for a first endurance flight – where are the limits? Until then the prop will be optimized, a new wing with reduced dihedral be built and maybe even an autopilot installed.