During the electrolysis process, water (H2O) is split into its components hydrogen (H2) and oxygen (O) by applying an electrical voltage in the electrolyzer. A "reuse" can only occur, if a reconversion to electricity is carried out, e.g. via a fuel cell, and the reaction product "water" is collected on site. In this case, highly purified water could be separated after the reaction and fed back into the electrolysis process.