A multi-year renewable amounts assessment for grid portions: the italian case

The increasing penetration of renewable energy sources (RES) in the Italian electricity system requires an evaluation of the integration capacity in the National Transmission Network. In this paper, a novel methodology to assess the maximum RES capacity (wind and solar photovoltaic) that can be integrated into different grid portions of the Central-South Italy is presented. The network constraints, the real distribution of RES connection applications, the sub-transmission network operation islands and the grid development projects progress are the main parameters considered in an integrated multi-year iterative approach. Starting from the National reference grid planned in post-2030 time horizon, grid models corresponding to 2030, 2028 and 2026 have been investigated removing development projects and reinforcements scheduled out of the reference year. The results show that the RES integration capacity increases significantly with the network reinforcements implemented between two consecutive timeframes, and that the main limitations are due to transmission lines congestion and system stability. The importance of a coordinated planning between the network and the RES is also highlighted, in order to optimize the use of RES capacity and while ensuring system security and efficiency.