Techno-economic assessment of renewable self-consumers and energy communities on a university campus in Italy

A new concept known as Renewable Energy Community (REC) has been introduced in the European directive RED II, promoting the use of renewable energy. This advanced innovation has the tendency to reshape the interaction between different players in the energy sector, offering substantial benefits including: (1) energy cost savings; (2) reduces demand-supply mismatch; and (3) lowers burden on the local grid. This paradigm is in its initial stages; therefore, in this work, a case study of REC evaluation is implemented at the University of Palermo, located in southern Italy. The University comprises 18 major buildings served by 10 Points Of Delivery (PODs). Through these PODs, energy is distributed to a single distinct building (6 PODs for 6 different buildings), and through a common connection to multiple buildings (4 PODs for 12 buildings). The components considered in the REC model are: (1) Photovoltaic (PV) to be installed on the roof of buildings; (2) Battery Storage System (BSS) for storing excess PV energy and reducing the intermittency; and (3) the connection with the local grid. The first objective is to plan PV and BSS capacities of each building: PV size is estimated from rooftop area analysis, while a cost degradation aware optimization approach is developed using Particle Swarm Optimization (PSO) algorithm to optimize the size of BSS while maximizing the battery’s net present value. The implemented REC model is compared under different scenarios to evaluate its economic and operational impact on end-users and on the local distribution network respectively. Regarding the operational impact, the findings indicated that the integration of PV with BSS under REC framework significantly reduces intermittency and improves the voltage profile of each POD of the network as the fluctuations drop in the stable range of 19.94 to 20.07 kV. However, in terms of voltage stability, the PV-only scenario improves voltage stability compared to other scenarios, as the voltages remain in a tight range of around 99–100% with less deviation. In an economic analysis, combining PV and BSS under REC framework and sharing excess energy is regarded as the most cost-effective option. For instance, in the case of POD connected to building “Agraria”, the scenario (PV+BSS) with the sharing of energy to grid reduced the electricity cost to 38,449.56 €, compared to the PV-only scenario (77,355.70 €), PV with sharing option (47,370.38 €), and the scenario (PV+BSS) without sharing option (61,478.57 €).