Assessment of the Energy Communities’ potential for providing flexibility. Optimization model proposal and study of the Italian and Portuguese legal framework.

The whole electrical system is facing a deep transformation with the purpose to integrate renewable energy sources (RES) and become more sustainable, a challenge that requires huge investments and the development of new mechanisms, mainly for the distribution sector and the electricity market. In this setting, demand-side flexibility (DSF) is stated to be a crucial tool to accommodate the grid changes and its management, optimizing renewable energy use and taking advantage of the arising active role of customers. Among the others, energy communities (EC) are playing their role in the European transition towards a less fossil fuel-dependent electricity system. Born under the Clean Energy Package to promote energy decentralization and people engagement, they are defined as voluntary organizations of people, autonomously ruled, which decide to be involved in distributed generation and related activities to provide economic, social and environmental benefits to their members rather than to be profit-driven. Their purpose encompasses promoting RES generation as well as serving the electricity system by providing flexibility services. In this sense, the EC seems to be particularly interesting for DSF because, being already an aggregation of customers, it can take advantage of its internal organization and be able to offer more valuable energy and flexibility products with respect to individual ones. For the time being, ECs are exiting from the pilot phase, which was mainly focused on self-consumption, but in the meanwhile, Member States are currently on the way to completing their legislation and regulation alignment with the European directives, extending the EC activities also to flexibility products. Therefore, the purpose of this work is to explore the potential of the EC as a provider of flexibility services for the grid, in name of a virtuous integration within the system. After having analyzed the legal and regulatory framework, and reviewed the literature on both energy communities and flexibility, an optimization model is developed for an EC receiving a flexibility request from the grid and managing it to be fairly distributed among its members, according to their possibilities and assets. To do that, assets are represented by MILP load modeling, including shiftable loads, water heaters, air conditioning, and battery; electric vehicles have been included, too. An EC manager (or management system) has access to the members' consumption profiles and it is in charge to reorganize the load scheduling from the announcement onward, and to calculate the amount of flexibility that should be delivered by each member, minimizing the discomfort. The tool has been tested by simulating an upward request (asking for a decrease in power) and modeling an energy community with four characteristic profile types: simple consumers, prosumers, prosumers with a storage system, and public buildings. Different scenarios have been explored, mainly changing the size and composition of the community, and the size of the requested service, according to the evolution trend of those products - opening to residential customers, mainly decreasing in size - in order to identify which EC characteristics can better match and manage the provision of such services.