Introducing the grid impact score: an indicator for DER impact on present and future grid states

With the implementation of new ambitious climate targets, e.g., FitFor55 or REPowerEU, distribution grids are experiencing a significant surge in the number of grid connection requests, primarily for Distributed Energy Resources (DER). This is especially the case at the low-voltage (LV) level. Since this unprecedented demand of requests presents substantial risks of delaying the interconnection of new DER and loads, there is an urgent need for a novel indicator providing transparency regarding the present and future states of the grid and the extent of their impact from DER integration. In this work, we introduce a novel concept, i.e., a “grid impact score”, to effectively estimate and manage the state of the grid. This grid impact score offers a comprehensive assessment of the grid safety limits and can be calculated using historical data, projected data considering future penetration rates of DER and projected data considering future penetration rates of DER combined with potential mitigation measures. We showcase the practical utility of the grid impact score when evaluating the present states of secondary substations and feeders in distribution grids, considering both European- and North American-type systems.