CITIES Innovation Center is a pioneer in research on energy systems conducting a wide range of projects on the topic. Research and solutions are developed with the aim to fully integrate energy systems, to enable an increased percentage of renewable energies. However, modelling of fully integrated energy system is a complicated task. Precise predictions rely on simulation and insights into existing energy system supply and grid infrastructures. This includes the access to and analytical treatment of big data from organizations operating within the energy sector. Thus, projects are in praxis intertwined with data analytics and cloud-based solutions conducted in close collaboration with our partners from the energy sector.