Europe wants to build a renewable, independent energy system. Wind power, photovoltaics, electromobility have already entered the market, Power-to-X has yet to. Therefore, studying these plants’ behavior in a real energy system is challenging. Power-to-X plants are often only modeled superficially in many studies, making it difficult to draw conclusions about them. This work aims to investigate the optimal design of the future European energy system and its power-to-X plants using a digital twin. The sectors electricity, heat, mobility, and power-to-X are fully coupled and optimized using linear optimization. Detailed evaluations show what a future energy system could look like, how power-to-X and the energy system interact, and how power-to-X plants should be designed and operated. Finally, the study estimates when power-to-X could be viable and how the system responds to risks. The results show that wind power and photovoltaics will be the backbone of future energy systems. Therefore, storage facilities will be needed. In addition to battery and pumped storage, power-to-X plants will take on this task. The produced fuels are responsible for storing energy long-term and transporting it from regions with good potential for renewables to regions with poor potential. The plants must be operated very flexible. This is reflected in the plant design - intermediate storage for hydrogen, CO2, and process heat is needed. Power-to-X process developers are provided with key data so that these plants can be better designed today to ensure maximum benefit in future systems. This work shows that power-to-X plants can only be economically viable when Europe is almost CO2-neutral, but then they are an integral part of the energy system. The study also shows that cost increase of power-to-X plants is one of the most significant risk factors on the way to a CO2-neutral Europe.weiterlesen