Improvement of Self-Consumption Rates by Cogeneration and PV Production for Renewable Energy Communities

The goal of decarbonization has driven the adoption of several intervention strategies across Europe, including the promotion of Renewable Energy Communities (RECs). This study analyses an electric REC in Italy to explore the performance of different potential energy mixes combining a biogas-based cogeneration (CHP) system and photovoltaic (PV) plants. The analysis is based on a real REC composed of 53 members (mainly companies) with a Self-Sufficiency Rate (SSR) of 92% and a Self-Consumption Rate (SCR) of 60%. Adding 550 residential consumers (apartments) to the REC, the total production matches total consumption, and both SSR and SCR converge to 84%. Compared to RECs that rely solely on PV systems, this case study shows that biogas integration leads to an increase of around 40 percentage points in both SSR and SCR—equivalent to an average gain of 0.4 to 0.6 percentage points for each percentage point increase in the CHP share of the CHP-PV production mix. The analysis quantifies how SSR and SCR vary not only with different biogas/PV production ratios but, more importantly, with variations in the total annual production-to-consumption ratio of the RECs. These results can guide the design of RECs tailored to the specific characteristics of local contexts.