Decentralized price setting in energy communities with e-mobility: ensuring budget balance and individual rationality

This paper deals with the design of price-setting mechanisms in Local Energy Communities integrating both prosumers and electric vehicle charging infrastructures. The problem is motivated by the increasing need for efficient and privacy-preserving coordination of distributed energy resources with high penetration of photovoltaic generation and flexible demand. To address this challenge, a decentralized price-setting methodology is proposed, based on Benders decomposition, which uses the dual information to iteratively construct optimal price signals while preserving user privacy. The approach explicitly enforces two key market properties: budget balance and individual rationality. The effectiveness of the proposed method is validated through several case studies of increasing complexity (4-bus, 15-bus, and 33-bus test systems). Results indicate that community-based pricing reduces costs compared to direct trading only with retailers. In particular, the proposed pricing strategy can lead to average individual savings of approximately 32%, while at the aggregate level it enables a reduction in total community electricity costs of around 7%. Furthermore, the results show that the proposed methodology ensures budget balance and guarantees individual rationality within the deterministic day-ahead coordination problem for all considered scenarios.