Energy transitions are high on political agendas. From a practical viewpoint, community approaches are deemed essential in order to transition from a predominantly centralized energy supply to a decentralized one, and to exploit the potential of renewable energies. In this paper, I discuss how the emergence of community-based energy projects can be analyzed from an institutional perspective. In this context, a 'community' is treated as an individual institutional order that shapes decisions. I examine how community structures the implementation of biogas cooperatives in the Autonomous Province of South Tyrol in Northern Italy. My findings suggest that 'community spirit', a cooperative tradition, and the norms of locality and responsibility are central drivers behind the emergence and constitution of biogas cooperatives. Not only do these institutional features of community influence the decision concerning which farmers are in or out but also plant location and scale. I argue that 'community' is a necessary analytical category for understanding community energy.