Nowadays the reduction of CO2 emissions in many sectors is a primary need: the goal of the decarbonization of the industrial sector and the attempt to find sustainable alternatives to natural gas is leading to the implementation of the Renewable Energy Resources (RES). The production of hydrogen by means of water electrolysis is one of the most studied technologies and it could play an important role in decarbonization, in particular if RES are exploited to feed the electrolysis process. In fact hydrogen is an optimal solution because it guarantees a long term storability and the possibility to decarbonize final sectors in which is technically not possible or not convenient, such as the high-temperature heat sector.