This thesis work has the main objective to develop and validate a dynamic model for a PEMFC stack system by using Modelica language, model which will represent the starting point for some future work in charge of Fondazione Bruno Kessler (FBK) within the framework of the European project CLEANER. After a brief introduction where statistics and data about today and future energy demand, renewable energy exploitation and emissions are presented along with some applications of hydrogen-based solutions and their providers, the discussion proceeds with a general description about the working principles of a fuel cell and an in-depth analysis of proton exchange membrane fuel cells.