From a purely chemical perspective, the water required for electrolysis is split into its components hydrogen and oxygen.<\/p>\n\n\n\n
18 g\/mol H\u2082O \u2192 16 g\/mol O + 2 g\/mol H\u2082<\/p>\n\n\n\n
To produce one kilogram of hydrogen, exactly nine kilograms of water are theoretically required. <\/p>\n\n\n\n
However, electrolysis requires ultra-pure water. Ordinary tap water or groundwater must therefore be filtered and purified beforehand (e.g. by reverse osmosis). During this treatment, approximately 20% of the water is lost as concentrate. In addition, the electrolysis process itself is not 100% efficient (e.g. due to water carryover on the oxygen side).<\/p>\n\n\n\n
Overall, a water requirement of approximately 12\u201313 kg per kilogram of hydrogen produced must be expected. Based on the heating value, this corresponds to just under 300 milliliters of water per kilowatt-hour of hydrogen.<\/p>\n\n\n\n
<\/p>\n\n\n\n
For comparison: the average consumption of a hydrogen vehicle is 1 kg\/100 km, meaning approximately 12 liters of water are needed per 100 km. A gasoline car requires approximately 18\u201336 liters of water (production of gasoline: water consumption 3\u20136 liters; assumption: fuel consumption 6 L\/100 km).<\/p>","protected":false},"excerpt":{"rendered":"