*Article* **Simulation of Coupled Power and Gas Systems with Hydrogen-Enriched Natural Gas**

**Yifei Lu 1,2,\* , Thiemo Pesch <sup>1</sup> and Andrea Benigni 1,2**


**Abstract:** Due to the increasing share of renewable energy sources in the electrical network, the focus on decarbonization has extended into other energy sectors. The gas sector is of special interest because it can offer seasonal storage capacity and additional flexibility to the electricity sector. In this paper, we present a new simulation method designed for hydrogen-enriched natural gas network simulation. It can handle different gas compositions and is thus able to accurately analyze the impact of hydrogen injections into natural gas pipelines. After describing the newly defined simulation method, we demonstrate how the simulation tool can be used to analyze a hydrogen-enriched gas pipeline network. An exemplary co-simulation of coupled power and gas networks shows that hydrogen injections are severely constrained by the gas pipeline network, highlighting the importance and necessity of considering different gas compositions in the simulation.

**Keywords:** gas network simulation; energy system simulation; hydrogen; power-to-gas; multienergy system
