The European Energy system is in transition towards clean energy and high efficiency. European citizens are at the centre of this transition. Empowered by a wider choice of services, they are becoming active players – prosumers (consumers and/or producers) – keeping energy prices at an economic optimum. Digitalisation is the revolutionary enabler for this transition of the energy sector; nobody can avoid it. We need an appropriate, reliable and secure communication system if the power system is to be operated with Dispersed Energy Resources (DER) in a dynamic way.