The new 36 kV standard voltage level to increase RES penetration in sub-transmission network

System efficiency and renewable technologies are the core elements of the energy transition, and their synergies are likewise important. In recent years the connection requests for RES power plants have significantly grown, mainly involving the High Voltage (HV) sub-transmission network. In this framework, the Italian Transmission System Operator (TSO) has designed novel technical and operational solutions allowing a secure and cost-efficient integration of new connections. This paper addresses the new 36 kV standard voltage level proposed for RES power plants with rated power lower than 100 MW. Furthermore, a representative case study on the southern areas of Italy is illustrated. Increase of RES penetration margin by exploitation of operation islands is also assessed.