Active energy citizens are leading energy transitions, co-producing new cultures, practices and structures of production and consumption. This article aims to understand if prosumerism – the collective participation of prosumers in energy projects with social, economic and environmental benefits to society – can be referred to as a social movement. The article draws on a review of Social Movements Theory and applies thematic analysis to characterize 46 prosumer initiatives in Europe. The collective identities, socio-political opponents, knowledge-making activities, collective learning, and collective action aspects of these prosumers are described. The results show that prosumer initiatives converge towards a transformative social movement. This movement upholds decentralized renewable energy production and consumption, and presents itself as a socially inclusive, transparent and participatory energy model, replicable across the globe, in what can be described as a collective action towards a decentralized democratic energy model. The discussion highlights relationships between prosumerism and framings such as energy justice (including energy poverty and gender issues), energy democracy, climate change action and anti-nuclear movements, to reach a conclusion considering the relevance of calling prosumerism a social movement, while opening up some avenues for future research.