The use of hydrogen produced by electrolysis, along with its derivatives (such as synthetic methanol and synthetic kerosene), is one of the solutions envisioned to decarbonise certain sectors such as the steel industry and long-distance sea and air transport. The development of a Europe-wide hydrogen network is considered to support electrolytic hydrogen production, provide access to unevenly distributed underground storage, connect renewable-rich regions with industrial hubs and, in certain areas, limit the cost of reinforcing the electricity transmission network. CEA I-Tésé is one of the partners in the French-German CrossHy research project. This 3-year project also involves an energy system modelling team from the German research center DLR and French gas TSO NaTran as an associated partner. The project aims to analyse the possible deployment pathways for hydrogen transport infrastructure in France and Germany. It includes a significant modelling part and relies on two complementary modelling tools:    - The open-source tool called REMix, developed by the DLR team, which can optimise energy system investment trajectories.    - The open-source tool developed by RTE called ANTARES which is used by the CEA-Itésé and NaTran teams to model the European power system. The project includes the development of a European-scale model, based on a combination of REMix and ANTARES tools, and a regional-scale model, based on REMix. One of the key challenges of the project is to consolidate a set of input data consistent across Europe, with several variants on certain key parameters such as the level of hydrogen demand at different time horizons. A more refined representation of consuming sectors is envisaged to better represent the potential flexibility of this demand. The post-doc is going to contribute in particular to:  (a) Enhance model inputs and hydrogen demand flexibility representation    - Consolidate input datasets for the various models    - Investigate methods to better represent hydrogen demand flexibility in both models; implement the required changes in ANTARES (b) Analyse and interpret model results    - Process and analyse the outcomes of the models developed in REMix    - Define and conduct relevant sensitivity analyses, in direct collaboration with DLR (c) Implement and evaluate model coupling    - Implement the coupling between REMix and ANTARES    - Analyse the results and assess the added value of coupling the two models (d) Communicate project findings    - Summarize and present the project results to various stakeholders, including public authorities. The post-doc will be based in either CEA-Saclay or CEA-Grenoble. Regular physical meetings between the French and German research teams are planned during the project; the post-doc will include a 3-month visit to Stuttgart to work and exchange with the DLR team involved in the project.