Sharing rules and the promotion of energy communities: A normative comparative analysis

A key challenge for energy communities is to structure peer-to-peer trade and distribute the associated benefits and costs. Central to this task is the establishment of a sharing rule. This study compares well-documented sharing mechanisms through the lens of five normative criteria drawn from game theory and social choice. The novelty of our approach lies in the use of normative criteria, rather than simulated or empirical data, as an evaluative framework to assess the rules. Since none of the existing mechanisms fully satisfies all five criteria, we propose the Weighted Constrained Equal Awards (WCEA) rule as an alternative. We show that the WCEA belongs to the family of sequential sharing rules and complies with the principles of efficiency, fairness, non-manipulability, individual rationality, and replacement monotonicity. Meeting these criteria is essential to ensure broad acceptance of the rule and support long-term cooperation among members of energy communities. The technical implementation of the rule is straightforward and does not require advanced software or hardware, making it accessible even for small-scale initiatives. By offering transparency, precision, cost-effectiveness, and fairness, the WCEA rule facilitates efficient day-to-day operation of energy communities and provides a point of comparison for future research in energy management.