Development of benchmark scenarios for sector coupling in the Italian national energy system for 100% RES supply to power and mobility

The urgence of decarbonization has pushed many countries to set ambitious net-zero CO2 emission targets by 2050. This requires a substantial transformation of energy sources, conversion methods, and final uses. This work investigates the structure of the future Italian energy system – in terms of power generation capacity, energy storage, mobility fuel shares – and assesses benchmark scenarios able to reach a fully decarbonized supply in power and transport sectors, considering their long-term evolution. The analysis adopts a multi-node multi-vector model that simulates the year-long energy system behaviour with hourly time resolution and optimizes sizing (installed capacities) and operation (energy flows). The model considers power generation from different sources, electric consumption, and mobility demand for energy vectors, focusing on electricity and hydrogen. The required installed capacities of RES power plants and energy storage systems appear to be extremely high (at least 10x today’s solar PV or more), but in general positively influenced by sector integration strategies and energy vector multiplicity. Energy storage and flexibility solutions are essential, combining battery storage, Power-to-Hydrogen, Power-to-Power, smart charging, and vehicle-to-grid. If capacity installation is limited (e.g., due to land availability), the need to satisfy consumption yields significant import requirements, which also depend upon the mobility mix and the decarbonization targets.