A call to action for building energy system modelling in the age of decarbonization

As urban energy systems become decarbonized and digitalized, buildings are increasingly interconnected with one another and with the industrial and transportation sector. Transformation strategies to cost-effectively integrate distributed energy sources, and to increase load flexibility and efficiency, generally increase complexity. This complexity causes challenges that the industry is unprepared to deal with. Today's simulation programs, and the processes in which they are used, have not been developed to meet the challenges of decarbonization. Nor have they been designed for, or do they keep pace with, the energy system digitalization. Modeling, simulation and optimization tools, and the processes in which they are used, need to undergo an innovation jump. We show a path to more holistic tools and workflows that address the new requirements brought forward by the increased complexity. Without concerted actions, the building simulation community will fall short of supporting the 2050 decarbonization targets declared by many governments.