German drinking water supplies are unaffected by the water requirements for electrolysis’s creation of green hydrogen. This is the outcome of investigations that the German Gas and Water Association presented today (DVGW).
The foundation was a 10 gigawatt (GW) installed electrolysis capacity by 2030. Around seven million cubic meters of ultrapure water are needed for this. This is equivalent to taking up to nine million cubic meters of freshwater from the environment. This is a minor amount in comparison to other uses. 450 used over 2019 million cubic meters of raw water for irrigation of only agricultural land. In the energy sector, cooling towers at power plants let off at least 300 million cubic meters by evaporation in the same year, which is more than thirty times what would be required for electrolysis.
Even with a long-term growth capacity of 40 GW, the DVGW estimates that the overall water demand in Germany will only rise by less than 1% as a result of the electrolysis-based production of green hydrogen. Dr. Wolf Merkel, a director of the DVGW, explains: “There is rising concern about the availability of our drinking water resources due to the escalating hot and dry spells. Our calculations’ findings demonstrate that the electrolysis capacity that legislators are presently considering does not result in a material rise in water demand throughout Germany.”
Angela Merkel emphasized the significance of taking into account regional circumstances right away. Planning for capacity should take into account factors like the quantity and quality of water resources available at the site in question as well as regional effects and long-term effects. This is especially true for areas that have recently experienced drought, such as those in the federal states of Brandenburg, Saxony-Anhalt, or Lower Saxony.
Other sources may also be utilized if there is a shortage of surface or groundwater. Seawater that has been desalinated can also be used offshore for electrolysis or in coastal areas. In accordance with the development plans, one-third of the electrolysis capacities will be put immediately at the wind farms in the North Sea and two-thirds on land, according to a study by the Offshore Wind Energy Foundation. The need for freshwater would decline as a result. The use of wastewater from sewage treatment plants, which can be cleaned and converted into ultrapure water for the electrolyzer, would also be a substitute source of raw water for areas distant from the ocean.
