Abstract A production cost simulation model for the NorthWestern part of the UCTE system is developed in this paper. Information from various sources was gathered and combined to produce an integrated representative model of the areas under study. Specifically, the technical and economical limits of wind power integration within the power system are highlighted, by means of observing and analyzing various unit commitment schedules under different scenarios. The main question refers to which level of wind penetration the power system can operate in a safe and reliable fashion, while the incoming wind power is completely integrated and correlations between system variables in adjacent areas are taken into account. By answering this question, the system planner will have the flexibility to arrange in the future the power system operation accordingly so as to decrease the operation costs to a minimum and increase the efficiency of the total system to maximum. An investigation of this problem statement can only be executed with global models, which take into account both technical and economic constraints and further optimize the operation of the power system.@en