*Article* **Integrating System and Operator Perspectives for the Evaluation of Power-to-Gas Plants in the Future German Energy System**

**Johannes Schaffert 1,\*, Hans Christian Gils 2,\* , Max Fette 3,\*, Hedda Gardian <sup>2</sup> , Christine Brandstätt <sup>3</sup> , Thomas Pregger <sup>2</sup> , Nils Brücken <sup>1</sup> , Eren Tali <sup>1</sup> , Marc Fiebrandt <sup>1</sup> , Rolf Albus <sup>1</sup> and Frank Burmeister <sup>1</sup>**


**Abstract:** In which way, and in which sectors, will renewable energy be integrated in the German Energy System by 2030, 2040, and 2050? How can the resulting energy system be characterised following a −95% greenhouse gas emission reduction scenario? Which role will hydrogen play? To address these research questions, techno-economic energy system modelling was performed. Evaluation of the resulting operation of energy technologies was carried out from a system and a business point of view. Special consideration of gas technologies, such as hydrogen production, transport, and storage, was taken as a large-scale and long-term energy storage option and key enabler for the decarbonisation of the non-electric sectors. The broad set of results gives insight into the entangled interactions of the future energy technology portfolio and its operation within a coupled energy system. Amongst other energy demands, CO<sup>2</sup> emissions, hydrogen production, and future power plant capacities are presented. One main conclusion is that integrating the first elements of a large-scale hydrogen infrastructure into the German energy system, already, by 2030 is necessary for ensuring the supply of upscaling demands across all sectors. Within the regulatory regime of 2020, it seems that this decision may come too late, which jeopardises the achievement of transition targets within the horizon 2050.

**Keywords:** energy transition; power-to-gas; PtG; hydrogen; H<sup>2</sup> ; energy system; energy modelling; energy system optimisation; system analysis
