The initial connection of renewable energy (RE) units to the distribution grid typically occurs without imposing complex technical constraints. However, as the penetration of decentralized generation continues to rise, it introduces challenges related to service quality, grid stability, protection planning, and capacity constraints. Therefore, connecting decentralized generation facilities to the medium-voltage grid requires adherence to specific technical criteria. A parametric study methodology needs to be established to address these issues. This chapter focuses on resolving the impact associated with the grid’s hosting capacity, which is critical for its operational integrity when integrating decentralized renewable generation. Additionally, disturbances like harmonics and flickers occur during the direct injection of power from small RE plants. To assess these impacts, a phased methodology has been developed and will be detailed in this study.