Modelling and Simulation of the German Gas Transmission Network with Hydrogen Blending

This study investigates the behavior of the German transmission gas network infrastructure with and without green hydrogen injection. Based on the simulation results of different scenarios, the challenges and criticality that arise with hydrogen blending are evaluated and analysed in detail. One of the main aims of this study is to simulate and evaluate the gas network steady-state simulation using open-source-only datasets and tools. To achieve this, the natural gas consumption data of Germany is first studied. After comparing two different open-source datasets, the dataset DemandRegio is chosen, which provides hourly data for gas consumption in Germany with a NUTS-3 spatial resolution. Then, in order to take into account the exchange of natural gas with the neighboring countries, the import and export data are provided by the German Network Agency (German: Bundesnetzagentur) with a daily resolution. For the network topology, the SciGRID_gas IGGIELGN dataset is used. It contains information about the pipelines, the consumers, entry and exit points, compressors, storage, and so on. After all the data required for the simulation are analysed and processed, the simulation is performed using the open-source tool GasNetSim, which is a relatively newly developed tool that can perform steady-state gas network simulations. In this tool, the gas mixture compositions and properties are modelled and calculated during the simulation, therefore it can be used to study gas networks with various natural gas compositions or hydrogen injection. The obtained results show the nodal pressure and flow rate in each pipeline of this transmission network, highlighting the pipelines that are more stressed and the ones with the highest pressure drop. The knowledge of these parameters is vital for a secure gas network operation. In addition, the simulation results with hydrogen rejection offers a good basis for regulating the amount of hydrogen that can be injected into the natural gas network, so that it does not exceed the permitted limit. It is worth mentioning that this study is limited by the lack of information on the controllable facilities, e.g. compressor stations. However, the results of this study still offer significant insights of the network operation and they also suggest potential necessary improvements in the open-source datasets.