In her pivotal book, “Governing the commons,” Elinor Ostrom shows that for coping with the tragedy of commons, institutions with communal property and informal enforcement (what we called Ostrom’s institutions) may efficiently rise. In Ostrom’s institutions users of a common resource becomes watchdogs and judges on other users’ behaviors and rule-makers on that resource, leading to superior information (in particular, additional information by actively monitoring users) about resource appropriation and more efficient rule-making process and punishment technologies toward insiders and outsiders. The objective of this paper is to use the theoretical framework behind Ostrom’s institutions to Energy communities (ECs) that represent institutional arrangements facilitating the massive shift to renewable decentralized generations. Indeed, quite similar to an institution à la Ostrom, ECs provide citizens with a more active role in the control and govern of renewable energy exploiting local commons.