Renewable energy (RE) prosumerism comes with promises and expectations of contributing to sustainable and just energy systems. In its current process of becoming mainstream, numerous challenges and doubts have arisen whether it will live up to these. Building on insights from sustainability transitions research and institutional theory, this article unpacks the mainstreaming by considering the range of institutional arrangements and logics through which these contributions might be secured. Taking a Multi-actor Perspective, it analyses the differences, combinations, and tensions between institutional logics, associated actor roles and power relations. Firstly, it unpacks how mainstreaming occurs through mechanisms of bureaucratisation and standardisation (state logic), marketisation and commodification (market logic), as well as socialisation and communalisation (community logic). Secondly, it highlights the concomitant hybridisation of institutional logics and actor roles. Such hybrid institutional arrangements try to reconcile not only the more known trade-offs and tensions between for-profit/non-profit logics (regarding the distribution of benefits for energy activities and resources), but also between formal/informal logics (gaining recognition) and public/private logics (delineating access). This institutional concreteness moves the scholarly discussion and policy debate beyond idealistic discussions of ethical principles and abstract discussions about power: Simplistic framings of ‘prosumerism vs incumbents’ are dropped in favour of a critical discussion of hybrid institutional arrangements and their capacity to safeguard particular transformative ideals and normative commitments.