The necessary energy transition to decarbonise power systems is leading to increasingly important challenges for the operation of power systems. On the one hand, the intermittent nature of renewable generation requires system operators to procure system services in larger volumes than in the past. On the other hand, the growing penetration of medium- and small-scale, flexible demand and storage systems in distribution networks might result in congestions or voltage problems in this grid level, but these resources could potentially offer system services, if they are aggregated effectively and there is appropriate coordination between transmission system operators (TSOs), distribution system operators (DSOs) and aggregators. Therefore, an interesting topic to be analysed is whether distributed energy resources can replace traditional generation in the provision of system services, how this replacement will affect the system operators' roles and how to improve the coordination between TSOs and DSOs. The CoordiNet project aims at demonstrating, through different TSO–DSO coordination schemes, options for providing system services with flexible resources located at different voltage levels. This study shows the Spanish demonstrators, in which REE (TSO) and the two largest DSOs, i.e. e-distribución and i-DE participate, as well as IIT Comillas and Tecnalia, among several European partners.The presented work has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 82441
