Energetic and economic advantages of energy communities: a case study referred to a southern Italian town

Energy Districts and Communities are at the heart of EU programs. Nevertheless, several challenges are encountered when bringing into fruition. Their convenience is not fully understood on a small scale, due to the complexity of the start-up practices, which make them more suitable for commercial or industrial companies. In this scenario the present study arises, aimed at pointing out to small communities, at condominium scale, the economic benefits, in terms of Net Present Value (NPV), deriving from the adoption of the new community plant configurations. Such indicator gives a glance of the total cost, both investment and functioning ones, to be sustained during the plant life, together with the enjoyed benefits. Particularly the investment cost is presently a big obstacle to the spread of renewable energy systems whereas the high operative cost of conventional plants is less adequately considered. In this frame, through the paper the satisfaction of the electricity needs of the users of a building, sited in Reggio Calabria (Italy), when their plant configurations turn from single grid-connected into community is analyzed using 2024 tariffs. From the study the economic advantages of the community result, pointing out an NPV increase (€ 3798), with a consequent reduction of the investment pay-back time for most users. The benefit increases (€ 24,918) when an energy intensive user joins the community. The study also considers a plant configuration equipped with storage, pointing out the reduced grid exchanges: a lower injection of 5.6 MWh and a lower withdrawal of 6.9 MWh. Concerning NPV, despite the batteries cost and their replacement every 10 years, only low reductions are observed, thanks to the great saving obtained by stored energy, that make the investment convenient. In the future the study will be enriched with the analysis of plant configurations that consider aggregation among adjacent buildings.