The green hydrogen economy is a key pillar in energy transition. Ambitious expansion targets have been set in the national hydrogen strategy . For achieving these goals, significant additional quantities of water must be extracted at regional level – for example, for the ENERGY HUB Port of Wilhelmshaven.
The German Energy Agency DENA reports that the ENERGY HUB Port of Wilhelmshaven – an association of more than 30 companies – plans to produce 194 tons of hydrogen per hour by 2031 using electrolysis. That's equivalent to 6.51 gigawatts of power. In total, according to the DENA report, the amount of water required at times of maximum consumption by all the planned plants adds up to at least 4,861 metric tons per hour in 2031. By way of comparison, the largest water association near Wilhelmshaven – the Oldenburg-Ostfriesische Wasserverband OOWV – delivered an average of 9,475 metric tons of water per hour to its 928,668 customers according to its 2021 annual report. During peak times of the ENERGY Hub, it would be as if the OOWV had to additionally supply a large city with half a million inhabitants with water; in a region where water use is already limited at times.
So far, the water strategy of the Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV) and the energy strategy of the Federal Ministry for Economic Affairs and Climate Action (BMWK) have stood side by side without any interconnection. Since responsibilities and legal framework conditions have not been clarified, this results in planning uncertainty for all actors involved.
Bottleneck for hydrogen economy
Some regions focus on green hydrogen technology, and at selected locations, the planning processes for hydrogen hubs are already well advanced. Planning uncertainty can have severe consequences for the parties involved, especially during hydrogen market ramp-up. The German Technical and Scientific Association for Gas and Water (DVGW) describes in a recent study that water resources in Germany are sufficient for the production of green hydrogen. However, is this assumption also plausible to hydrogen sites and regional actors who are already suffering from extreme drought and water scarcity at the present time? Some regions are rightly concerned, as a study evaluating hydrogen sites in Lower Saxony shows. For the district of Leer, for example, it advises against extracting water from groundwater.
Transparency and knowledge defuse conflicts and create planning certainty
Together with partners from the humanities and natural sciences, Fraunhofer UMSICHT develops an innovative dialogue process. The process is intended to be implemented in hydrogen model regions with water and energy suppliers, municipalities, and society. In parallel, Fraunhofer researchers prepare studies on the availability, market, costs and maturity of technologies for the treatment of different water qualities for electrolysis. Complete site analyses are also carried out.
Supply gaps: Technologies tap alternative water sources
Fraunhofer UMSICHT identifies alternative water sources that are not in direct competition with drinking water production and irrigation. These can be, for example, industrial wastewater and treated wastewater from municipal wastewater treatment plants, or brackish water, and other site-specific water sources. To this end, treatment processes are developed from laboratory scale to pilot scale, with the aim of using them for alkaline electrolysis or polymer electrolyte membrane (PEM) electrolysis.