At a time when decarbonization constitutes an issue of global relevance, hydrogen is seen as one of the most promising solutions. To date, around 96% of hydrogen is produced from fossil fuels, in processes like steam methane reforming (SMR) or coal gasification, while only the remaining 4% is produced in cleaner ways like thermochemical cycles and, especially, water electrolysis. This last method is based on water splitting into hydrogen and oxygen through chemical reactions driven by electrical energy or solar energy in the case of photoelectrolysis. Nowadays, the main types of water electrolysers, distinguished on the base of the electrolyte used, are essentially three: alkaline water electrolyser (AWE), proton exchange membrane electrolyser (PEM) and solid oxide electrolysis cell (SOEC).