Technical-economic evaluation for maximizing the self-consumption contribution in an energy community: The case study of Pattada in Sardinia

Ministerial Decree 414/2023 implements Legislative Decree 199 which defines the conditions and methods under which producers, consumers, and prosumers have the right to organize themselves into Renewable Energy Communities (REC), promoting the production and sharing of electricity from renewable sources. The economic feasibility of an energy community is largely influenced by its investment options: public capital only, third-party co-financing, or direct investment by interested households. A common issue in these cases is the allocation of costs among local community members to ensure cost recovery. To evaluate the feasibility of an Energy Community, an economic analysis with different technical and economical options is conducted, considering various cost allocation methods. The analysis is carried out in the case study of Pattada, a small municipality in northern Sardinia, and is focused on the availability of hourly consumption of public buildings and of two energy-intensive utilities in the tertiary sector. Residential consumption has been modelled based on the indications provided by the GSE and validated for some practical cases through targeted experimental measurements. Different scenarios were analysed by varying the size of the plants intended for self-production, the percentage of capital financing, the types of users and the number of residents adhering to the REC. He results confirm that the most favourable incentive tariff is obtainable minimizing the amount of energy fed into the grid. From an economic point of view, the participation of residents in energy generation is always favourable to the improvement of the NPV for all the prosumers. The higher profits are obtained without capital contributions, obviously due to the higher amount of the corresponding premium rate. On the other hand, capital contributions play an important role in the entry of new prosumers, especially in the residential sector, contributing to broadening the community pool. The interplay between distributed generation, energy storage and active participation in grid flexibility not only improves overall energy efficiency but also helps to reduce environmental impacts and promote greater energy independence.