How much is the advisable self-sufficiency of aggregated prosumers with photovoltaic-wind power and storage to avoid grid upgrades?

This paper defines, with respect to the consumption, the maximum value of self-sufficiency that can be reached by users, who decide to install photovoltaic (PV) modules, wind turbines and electrochemical storage. The primary goal of the aggregated users, who become prosumers, is assumed the achievement of the best match between power profiles of loads and power profiles of generators. Such best match is obtained thanks to an appropriate procedure to design the sizes of generators and storages. In this procedure, power ratings of PV and wind generators and energy capacities of batteries are chosen to attain the highest levels of self-consumption and the lowest power exchange with the grid according to the load profile. Thus, the upgrade of transformers and lines is avoided and there are benefits for both prosumers and grid operators. The simulation results are very realistic, because the inputs, in terms of irradiances for PV modules, wind speeds for turbines and powers for loads, are accurate measurements. The return on investments is estimated according to current costs and market rules. The results can be useful to plan the future electricity mix in the Mediterranean areas.