Critical Grid Situation (CGS) is defined as a critical situation which cannot be solved solely on national level. To solve the situation, coordination between one or more TSOs is required. More specifically, in the report of the ENTSO‐E task force for CGS (approved in September 2017), a Critical Grid Situation is defined as: “A Critical Grid Situation is a potential emergency state, c.f. SO GL article 18(3), identified in the operational planning phase, when all the available regular countermeasures (Remedial Actions) are exhausted and therefore TSOs are required to take regionally co-ordinated extraordinary countermeasures.”
CGS may be triggered when rare events with foreseen severe consequences occur. Typical examples of possible events that may trigger CGS are extreme weather conditions, strikes in the power industry, fuel supply shortage, forest fires, etc. CGS can also be triggered based on the results of CSA, OPC, and regional STA.
In all the above-mentioned cases, the affected TSO(s) can activate the CGS for the affected business days or timestamps in order to take regionally coordinated extraordinary countermeasures aiming to ensure the reliable and secure grid operation. In such events, SEleNe-CC facilitates the coordination between all involved TSOs and assists with the analysis of the situation, making also sure that all actions determined during the coordination phase are tracked and reported.