Hydrogen produced in a climate-friendly manner is expected to play a decisive role in the energy transition and the achievement of climate targets. For this reason, the German government intends to comprehensively develop the required technologies in three “hydrogen lead projects”. An important point here: the transport infrastructure. In the “MechaMod” project, which is part of the “System Analysis” research network of the “TransHyDE” lead project, Bonn-Rhein-Sieg University of Applied Sciences (H-BRS) is describing and simulating in detail the behavior of important plants in future hydrogen networks and their coupling with power grids. It thus creates a basis for further investigations of a network infrastructure for hydrogen.

This new network infrastructure is to consist primarily of rededicated natural gas pipelines. The Federal Ministry of Education and Research is supporting the project with a total of 624,000 euros over four years.

At present, natural gas makes an important contribution to the energy supply in Germany. According to the Federal Ministry of Economics, there is a pipeline network of 511,000 kilometers to bring the energy source to industry, power plants and other consumers (heating, cooking). This pipeline network consists of different components. As gas flows through the pipes, it slows down due to friction and a pressure drop occurs. This is why this is compensated for every 100 to 200 kilometers in so-called compressor stations – such as the one in Cologne-Porz. The question now is whether and how the natural gas network can also be used to transport hydrogen.

In the Systems Analysis Research Network, a team of more than 20 partners simulates how the network infrastructure will develop over the years on a Germany-wide or local level.

“We describe in simulations what the consequences of transit are in different dynamic scenarios, especially in terms of regional capacities, quality, secure supply,” says MechaMod project leader Prof. Dr. Tanja Clees, who is a member of the board of directors of the Institute for Technology, Resource Conservation and Energy Efficiency (TREE) at H-BRS.

The project focus in MechaMod is on detailed physical-chemical modeling for all mechatronic equipment in the grid – i.e., from the electrolysers (in which water is split into its components hydrogen and oxygen) to the compressor stations and controllers, to possibly converted gas and steam power plants. Possible fuel cell power plants, which do not yet exist in Germany, are also part of the simulations. In these, water is produced from hydrogen and oxygen, and the resulting energy is used in the form of electricity and heat.

In its simulations, the university can already build on experience with hydrogen in industry. “This is not a new technique,” says H-BRS scientist Clees. For example, a 240-kilometer hydrogen network has long linked the chemical sites in Dormagen and Leverkusen with the Ruhr region. “This shows that people don’t have to worry about hydrogen being transported through pipelines,” Clees said.

In the MechaMod project, the research professor is now calculating different scenarios in which several questions play a role: How much heat is generated during electrolysis? In what quality is the hydrogen sent into the pipelines? Are there any other impurities in the pass-through? What influence does the composition of the gas have on systems and pressure drop? How do the gas and electricity grids react with each other? “We want to neatly describe the behavior of hydrogen and thus lay the foundation for further research,” Clees says. The team is also building software modules that will subsequently serve as the foundation for the project partners’ investigations.

“The pipeline network cannot be converted to hydrogen as easily on the fly, as is currently the case in parts of Germany with the conversion from low-calorific natural gas from the Netherlands to high-calorific natural gas from Norway or Russia,” Clees says. What is clear, however, is that the entire energy transport system will be rebuilt in the next few years. In concrete terms, this means that in 2019, an energy demand for industry and households amounting to a calorific value of 900 terawatt hours (TWh; one terawatt hour corresponds to one billion kilowatt hours) was covered by natural gas. By 2050, a projected demand of more than 1,000 terawatt hours is to be met half by hydrogen and half by synthetic methane or biomethane. To do that, Clees said, the transmission system would have to be split.
With her research, she is laying a foundation for the rebuild. At the same time, however, she says: “We have to significantly reduce energy consumption as a whole, there is no way around it. The current war in Ukraine and the accompanying sanctions only make this all the more drastic for us”.