In Europe different trends and issues may strongly impact on the power transmission system. This poses new challenges to the European TSOs (Transmission System Operators), whose role becomes more complex. In this frame, transmission expansion planning criteria crucially need to be revised and extended towards advanced solutions.
The present paper results from the activities carried out within the European research project REALISEGRID. After introducing the European context issues and reviewing the current transmission planning practices in Europe, this paper focuses on the methodology developed to perform the cost-benefit analysis of new grid investments in a pan-European perspective. Some key results of the methodology application on a European transmission network testbed are also part of the paper.