Fueling the Future: Optimizing Power-to-X Production in Renewable Energy Hubs Through Flexible Operating Units

This paper presents a mixed-integer linear programming optimization model for analyzing Power-to-X energy hubs, with a special focus on investment decisions and variable efficiency. The energy hub model includes the use and generation of side products such as carbon dioxide or waste heat. A case study in combination with a sensitivity analysis of a Power-to-X e-methanol plant in Kassø, Denmark, illustrates the application of the model. The assessment of the production of synthetic fuel uses levelized cost of methanol, carbon dioxide emissions, and the necessary carbon price for economic viability. The levelized cost of methanol for the status quo is in the range of 1375.31 €/t to 3546.07 €/t today and 931.68 €/t in 2050. Results indicate that investment costs and electrolyzer efficiency have the strongest impact. The carbon dioxide emissions reveal that, due to a significant reliance on grid power, the environmental performance of the Power-to-X plant is comparable to that of fossil-based methanol production. These findings highlight the importance of optimizing both economic and environmental aspects in the design of Power-to-X energy hubs.