The energy transition in Germany and many other countries in the world brings up entirely new challenges for the energy supply industry. Adequate and reliable energy systems - especially in the electrical system - are the prerequisite for our modern civilisation and a productive industry. The transformation towards renewable energy sources like solar and wind power is accompanied by a geographical shift of generation to the countryside as well as towards the sea due to the higher space requirements. The fluctuating and volatile character of the weather-dependent renewable energy sources also leads to an increasing temporal divergence between energy generation and demand. Without appropriate changes to the structure, organisation and control of the energy systems a large share of the potential renewable energy supply would go unused, since not enough consumers or storages would be available at the same time or the energy grid would not be capable to transport the energy from generators to consumers. Such restrictions with the use of renewable energy sources would have to be compensated by conventional power plants, which upon the use of fossil fuels would contradict the goal of climate neutrality in the first half of the 21st century. Obviously, the integration of flexibilities, storages and sector coupling technologies on a large scale essential for the success of the energy transition and a secure future's energy supply. This brings up the question how a climate neutral energy system of the future can be organised, planned, and operated optimally in regard to economic feasibility, security of supply, and sustainability while utilising renewable energies and flexibilities.

The research project "ZellNetz2050", sponsored by the Federal Ministry for Economic Affairs and Climate Action, pursues the objective to develop a comprehensive system and market design on the basis of the Cellular concept (or Web-of-Cells concept) that was first formulated by the German VDE in 2015, and to provide a proof-of-concept for a cellular energy system through extensive as well as detailed simulation models. In the process, all energy sectors and the coupling between them as well as all areas of application in industry, mobility, and buildings are considered.  Basis of the simulation is one of the most extensive and detailed energy system models, enabling investigations from the national level all the way down to individual building connections. Two simulation models are being employed: an optimisation model that optimises all available technologies in the energy system in hourly intervals with regard to their techno-economic characteristics, and a real-time operational model that is used to show the principal operational manageability based on a partially dynamic model with a frequency resolution of 100 milliseconds. The scenario framework underlying the simulations is mainly taken from an almost climate neutral scenario for 2050 from the 2018 dena-study Integrated Energy Transition, and is accompanied by several other prognosis for the state-of-the-art of relevant technologies for the target year.