Fraunhofer-Gesellschaft
Offshore conditions are ideal for generating renewable electricity. The production of green hydrogen in offshore plants, using wind energy without a grid connection, can significantly reduce costs compared to onshore production. The direct coupling of the wind turbine and the electrolyzer in an innovative system makes it possible to operate without a connection to the power grid. The flagship project H2Mare, funded by the German Federal Ministry for Education and Research (BMBF), is researching the production of green hydrogen and other power-to-X products offshore, for the future large-scale production of offshore hydrogen. Besides other project partners, Fraunhofer IWES is supported by a cooperation with Fraunhofer IWU, IMWS, IGB and ICT.
Investigation, analysis and modeling of stack components and their degradation behavior
In the field of stack component analysis, Fraunhofer IWES conducts chemical, electrochemical and mechanical testing series on laboratory cells and stacks (25 cm2) and on a research stack developed in collaboration with Fraunhofer IWU, in order to determine specific material properties, performance and degradation behavior under simulated offshore conditions. Changes in material properties are evaluated at a microstructural level and correlated with macroscopic measurements, operating conditions, and environmental factors. This helps to identify causal relationships using models and to derive recommendations for membrane and material optimization. The ultimate aim is to construct a suitable test infrastructure.
100 m³ seawater tank as a test rig for water treatment
Within the project, Fraunhofer IWES is also building a test rig for testing seawater desalination plants connected directly to a PEM electrolyzer. The aim is to use the waste heat generated during electrolysis to supply the process heat required by the desalination plants. This could significantly increase the overall efficiency of hydrogen production. Current research focuses on the mutual compatibility of the components and the system behavior with the highly dynamic electrical output from a wind turbine. The electrical connection of the PEM electrolyzer is initially intended for simple electrical tests, but during the project it should be possible to connect real wind turbines to the test field, or to carry out dynamic electrical tests using a hardware-in-theloop (HIL) simulation.
Techno-economic simulations for optimal system dimensioning
Co-simulation in the H2Mare project is an essential tool for the development of modular energy systems. The interchangeability of models through a standardized interconnection concept leads to shorter development times and increases the reusability of simulation models. At Fraunhofer IWES, models are established to map the entire value chain, and are linked together by functional mockup units (FMUs) in co-simulation. A simulation platform with an integrated interconnection concept for models and optimization via co-simulation was developed for this purpose. Co-simulation plays a central role in the project. It enables the reuse of models and their reconnection in a new context without any major additional work. Overall, operation and maintenance, wake calculations (Foxes), operational management and the WEA-ELY system are the focus of investigations.
The H2Mare flagship project and its sub-projects started in April 2021 and are scheduled to conclude in 2025. The goal is to obtain key insights and demonstrators for direct-coupled hydrogen electrolysis, to pave the way toward a demonstrator in the MW range and initial projects in the North Sea later this decade.