A Techno-Economic Assessment to Define Inertia Needs of the Italian Transmission Network in the 2030 Energy Scenario

Italian generation scenario, as many others, is foreseeing the replacement of conventional Synchronous Generators (SGs) in favour of Renewable Energy Sources (RES), thus leading to a reduction of the overall system inertia. This paper provides a techno-economic methodology for the estimation of the amount of additional inertia that will be needed in the Italian Transmission Network in the 2030 scenario, in order to limit the Rate of Change of Frequency (RoCoF) within sustainable limits. Moreover, the algorithm optimally distributes Synthetic Inertia (SI) contributions from RES and Battery Energy Storage Systems (BESSs) and the installation of new Synchronous Compensators (SCs) among the Italian market areas. The method is designed to be sufficiently simple to process a significant number of working scenarios and the relevant quantity of information owned by the TSO. Nevertheless, the results have shown to be highly accurate as demonstrated by comparison with detailed time domain simulations.