Massimo Gallanti*, Riccardo Vailati*, Maurizio Delfanti**, Marco Savino Pasquadibisceglie**, Mauro Pozzi** CIRED 2009 20th International Conference and Exhibition on ELECTRICITY DISTRIBUTION Praga, 8-11 Giugno 2009 * CESI RICERCA ** POLITECNICO DI MILANO This paper describes a procedure developed by the authors with the aim to evaluate the capability of Medium Voltage (MV) busses to accept power injection from dispersed generators and to support the distribution system operators in facing the growing penetration of dispersed generation, especially due to Renewable Energy Sources (RES). This simple procedure simulates an increasing power injection at every bus of the considered sample and checks the violation of operating limits in order to determine the maximum admissible nodal injection. The procedure is applied to a huge network data set, corresponding to real Italian MV grids and representing a significant subset (6%) of the system. Results presented in this paper could be a robust and statistically significant background for technical and economic considerations about the limits for penetration of dispersed generation in the Italian system.