To achieve decarbonization of the energy sector, the analysis of the power grid behavior under a high share of renewable energies is fundamental. However, in its current state, the electrical grid is not adapted to such a scenario due to volatile/uncertain profiles and limited hosting capacities in “weak” grid areas. Energy models and long-term prospective studies are needed to adapt the power grid to new paradigms and to reshape the grid and the electricity mix jointly considering the economic, technical, and environmental constraints.