Systemische Untersuchung der Wasserverfügbarkeit für den Hochlauf der Wasserstoffwirtschaft

Kurzfassung

In the northwest of Lower Saxony, numerous hydrogen projects are planned. The current goal is to install electrolyzers with a total capacity of 7.5 gigawatts of electrolysis power. The aim of this master thesis is to determine whether the electrolysis process is limited by water availability. Firstly, the water demand of the electrolysis process and the water use as well as the water supply in the study area are clarified through a literature review. Subsequently, the water availability is calculated for the current period as well as four future scenarios using an index method, and compared to the water demand of the electrolysis process. In a second approach, the regional drinking water network is represented by a network model. The supply of drinking water in the network can then be compared with the water demand of the electrolysis process to identify potential limitations. However, the water demand of the electrolysis process remains unclear, and examples for large electrolyzers and their water demand do not yet exist. Literature values span a wide range, so five cases were developed for the water demand of different electrolyzers in this work. It shows that sufficient water is available in the study area at all planned locations today as well as in the future, but some sites can be identified which are more suitable for an expansion of the electrolysis. The spatial distribution of water availability can be used for planning locations from a water resource management perspective. Furthermore, it is possible to plan operation schedules that consider critical time periods throughout the year by using the temporal distribution of water availability. Additionally, it shows that the supply of process water for the electrolysis process from drinking water is possible. However, the water demand for cooling the electrolyzers far exceeds the current possible drinking water supply and must therefore be covered by alternative sources.