Renewable energy communities (RES communities) are a growing and extraordinarily multifaceted phenomenon which involves a range of possible activities around renewable energy (notably, production, supply, distribution, sharing and consumption) collectively carried out by citizens, often in partnership with small and medium enterprises and local public authorities. The Clean Energy Package (CEP) is expected to represent a turning point for the development and diffusion of RES communities in Europe, as for the first time both their very existence and their potential role in the energy transition receive legal recognition at the EU level. By 2021, all Member States will have to transpose the CEP’s Directives into national legislation, thus including the definition of an enabling framework that promotes RES communities. However, substantial room for manoeuvre is left to Member States in accomplishing the task. The present report analyses the phenomenon of RES communities in Europe and identifies plausible (qualitative) scenarios for their possible development over the next decade, at this very special time. It does so by carefully reviewing the socioeconomic literature on RES communities (Chapter 1), by carrying out three case studies of different types of RES communities (Chapter 2), and by analysing how the CEP provisions may be implemented by Member States and so affect the uptake of RES communities (Chapter 3).