Financial Optimization of Renewable Energy Communities Through Optimal Allocation of Locally Generated Electricity

This paper proposes a practical modelling solution to the problem of sharing distributed renewable electricity generation in the context of renewable energy communities. According to this approach, the economic benefits of community members, derived from their participation in the community, are shared by means of repartition keys , which represent the proportion of total local electricity to be allocated, ex-post , to each community member. These keys are computed through a centralised optimisation framework that optimally allocates the electricity generated within the community (i.e., local electricity) among the community members so as to minimise the sum of the electricity bills of all community members. The electricity bill sent to each community member can be directly extracted from this solution. Building on this concept, we also introduce two additions to the basic algorithm, aiming to enhance the stability of the community, which a global bill minimisation may fail to ensure (e.g., very asymmetrical solutions between members may lead to some of them opting out). The first addition is the computation of the self-sufficiency rates of the community members, defined as the proportion of the electricity demand covered by local electricity, which can be exploited as a revenue sharing mechanism. The second addition is the use of initial repartition keys based on which the optimised ones are computed, so as to ensure a minimum contractual level of revenue for each of them. We have tested our methodology with a broad range of scenarios illustrating its ability to reduce the sum of the electricity bills of the community members and to share the revenues ensuring the stability of the renewable energy community. Our results show that creating a community using this methodology can potentially reduce the electricity costs for all community members, and that self-sufficiency rates and initial keys can be used to stabilise the community by performing revenue sharing among them.