Nowadays, the danger represented by the utilization of greenhouse gases shifted the global energy scenario towards renewable energies such as solar, wind, tide, etc. Despite the global need for a green transition many efforts are necessary, mostly due to the intrinsic intermittent nature of renewable sources. Among different energy carriers, hydrogen is particularly promising as vector. Its application proposes a sustainable energy conversion pathway as well as a potential storage solution for renewable energy sources. Hydrogen can be produced by water electrolysis (i.e., green hydrogen) with low-carbon emissions. The most efficient electrolysis cells to produce green hydrogen are high temperature electrolysis cells (HTEs).