General provisions
Article 27
1. No later than six months after the decision on the generation and load data provision methodology referred to in Article 16 and the common grid model methodology referred to in Article 17, all TSOs shall organise the process of merging the individual grid models. 2. No later than four months after the decisions on the capacity calculation methodologies referred to in Articles 20 and 21, all the TSOs in each capacity calculation region shall jointly set up the coordinated capacity calculators and establish rules governing their operations. 3. All TSOs of each capacity calculation region shall review the quality of data submitted within the capacity calculation every second year as part of the biennial report on capacity calculation and allocation produced in accordance with Article 31. 4. Using the latest available information, all TSOs shall regularly and at least once a year review and update: (a) the operational security limits, contingencies and allocation constraints used for capacity calculation; (b) the probability distribution of the deviations between expected power flows at the time of capacity calculation and realised power flows in real time used for calculation of reliability margins; (c) the remedial actions taken into account in capacity calculation; (d) the application of the methodologies for determining generation shift keys, critical network elements and contingencies referred to in Articles 22 to 24.