This chapter focuses on citizen energy cooperatives in the Upper Rhine Region (URR), analysed as raising “communing” issues in the often mentioned transition process towards a decarbonised and decentralised energy future. Two aspects appear pivotal. On the one hand, energy issues are understood as a system, through a relational approach (between different actors, between production and consumption, etc.), as pointed out by the literature both in terms of socio-technical systems and of social transactions. On the other hand, transformations are taking place continuously, including hybridisations when moving from enunciations to practical and territorialised experiences. Based on a sociological fieldwork study of these initiatives in the three French, German and Swiss parts of the URR, the contribution examines successively: (i) the relations between commons, territories and energy cooperatives; (ii) the balance between “common good” and “common project” around the two issues of ownership and of the possible alternatives to the market; (iii) the possibility of leading a “common action”, when it proves to be in fact socially and spatially selective. Transversally, the author sheds light on the fine line separating “common goods” from “club goods” in the field of renewables.