Electrolysis systems are the key technology to produce hydrogen from renewable energy sources. The modeling and simulation of proton exchange membrane (PEM) electrolyzers and the connected power grid are a challenge due to highly fluctuating loads in the available electrical power. Our study focuses on the modeling of the electrolyzer and its balance of plant with varying loads resulting from different energy sources. The balance of plant contains a water supply system, the electrical power supply and processes for treating the produced hydrogen, in particular drying. The electrolyzer model is validated using steady-state and dynamic data from the literature. Thereby, it is shown that the developed model accurately represents the measurement results from the literature. Furthermore, we implement an empirical degradation model to assess the effects of different use-cases on the efficiency of the electrolyzer.

Solid-state batteries are promising for electric mobility as they potentially offer higher energy densities and therefore driving range, long-life and safety. They come with changed thermal properties and thermal management requirements. In this paper a comparison of a solid-state battery system with a state-of-the-art liquid battery system is presented. This study compares a solid-state battery with a state-of-the-art liquid NMC battery for an electric coach on typical real-world long-distance routes, including fast-charging. The thermal management is performed by a reversible R744 heat pump. By designing both battery systems for the same energy capacity, the solid-state battery releases more heat during fast-charging. At the same battery system size, the solid-state battery significantly outperforms the liquid battery system in driving range and does not need more cooling.