As urban energy systems face growing demands for efficiency and grid stability, the integration of 5th generation district heating and cooling (5GDHC) systems offers substantial potential for enhancing grid flexibility. This work investigates the flexibility capabilities of 5GDHC systems by assessing their Load Shifting Potential (LSP) through the simulation of six distinct users’ substation configurations. These configurations are evaluated for their ability to shift load during peak periods and reduce dependence on grid electricity, with a particular focus on integrating renewable energy sources and energy storage solutions. The configurations considered for heating include setpoint modulation strategies, where temperature setpoints are adjusted by -1°C and -2°C during peak hours, as well as thermal storage systems. These storage systems are charged during off-peak hours and discharged during peak demand, with some configurations incorporating solar collectors to harness additional renewable thermal energy. Battery storage systems, which store electricity during off-peak times and discharge during periods of required flexibility, and a hybrid PV with battery configuration were also evaluated. For cooling, similar strategies were employed, including setpoint modulation of +1°C and +2°C, battery storage for shifting electricity demand, and a PV with battery setup aimed at enhancing flexibility by combining renewable generation with storage. The flexibility potential of these configurations was assessed using thermo-electrical models that simulate the operation of 5GDHC systems integrated with user substations. The analysis was applied to a real case study involving six buildings – offices and dwellings – located in Naples. Results reveal that configurations incorporating thermal storage and solar thermal collectors offer the highest flexibility during heating operation, achieving an LSP of up to 77%. The PV with battery setup demonstrates a flexibility potential of 94% during cooling operation. The findings demonstrate the capacity of 5GDHC systems to support grid stability by reducing peak energy demand and enhancing energy self-sufficiency.