Abstract
The integration of high shares of variable renewable energy sources is an aspect that is acquiring importance as it can lead to integration problems. The three main options to achieve this task are the enlargement and reinforcement of the grid, the use of storage devices, and demand side management. A modelling approach is applied in this study to evaluate the maximum level of renewable energy integration for the Italian power system when adopting electric storage. Firstly, the integration trend has been investigated starting from the production profile of variable renewable energy sources. The results show that the optimal combination of wind and solar energy to maximize the integration of renewables is 55% and 45%, respectively. Afterward, the impact of storage systems has been evaluated in the case of high renewable energy penetration. An optimization approach is then applied to assess the best mix of solar and wind energy while minimizing the costs. Results show that the best share of renewable energies stabilizes on 60 - 70% of wind production and 40 - 30% of solar production due to higher costs of rooftop photovoltaic systems.