This paper proposes a summary of a preliminary technical economic study that has been promoted by the Gran Port Maritime de Marseille (GPMM) and Costa Crociere, which was focused on the possible integration of distributed renewable energy sources at port (i.e. mainly photovoltaic power generation). These were mainly aimed at powering two cruise ships connected at the port electric grid at the same time, by means of an innovative Onshore Power Supply (OPS) system. Going towards a net zero emission port, also the possible use of bio-methane (bioCH₄), produced by means city waste in a site close to the port of Marseille, has been considered in the technical assessment as possible solution for powering a high temperature reversible fuel cell (revHTFC) capable of producing hydrogen or electricity, whether it is used as an electrolizer or as fuel cell, respectively.