In a context of energy transition and increasing intermittency of the electricity fleet due to the growing Renewable Energy Sources (RES) plants, the large - scale use of storage systems, such as Battery Energy Storage System (BESS) becomes necessary to contribute to the stability of the complex energy apparatus and encourage the abandonment of conventional production plants, still relying on fossil fuels. In this thesis project it was analysed the behaviour of a grid connected BESS facility owned by Edison S.p.A., located in the South of Italy, in Calabria region, Altomonte (CS). The work is aimed at studying the optimization potential of the Lithium - ion based battery plant within the current and future energy trading background.