The increasing penetration of distributed generation (DG) could cause positive and adverse impacts on distribution power grids. The study of these effects could lead to methodological guidelines for sizing and location of renewable energy sources. In this paper several simulations of a distibution system of MV with different locations and penetration levels of DG are performed. Performance parameters as transmission capacity and voltage level are calculated and the impact of the different penetration scenarios is assessed. Finally a relationship among benefits, the Hosting Capacity (HC), and the distance between feeder-head and DG location is characterized. A new index is proposed to value the better location of units and generation power based on this relationship.