Rotocycloid propulsion presents interesting performance as a possible long-term alternative to helicopters in a far future. It will lead to increase the energy efficiency of VTOL vehicles. This paper focuses on optimization of an airship with the possibility up to 2000 h/year of photovoltaic propelled flight at a cruise speed about 20 m/s. This paper demonstrates the feasibility of this airship concept and presents a full dimensioning according to the CDE (Constructal Design for Efficiency) developed at University of Modena and Reggio Emilia. The proposed solution has been deeply analyzed and the analysis of performances has been presented. The results allow thinking to a novel class of vehicles designed specifically to take the maximum advantage by this propulsion method.