Transition management uses the depoliticized, rational discourse of systems terms, social learning and societal reflexivity. Transdisciplinary sustainability science research similarly uses the politically neutral terms of supporting the coproduction and integration of different types of knowledge. Yet both are clearly normative, resting on notions of participatory democracy and adopting environmental and social sustainability as explicit norms. Here we present the case of a transdisciplinary transition management arena in Peru, convened to develop a vision of a lower carbon, more decentralized and resilient national energy system. We show how the characteristics of the arena can help to foster the necessary conditions for empowerment and how these in turn both support – and are supported by - the ability of participants from different backgrounds generate shared problem statements, visions and strategies, building towards a coalition for change. While it remains to be seen how politically influential such arenas can be in the medium and long term, we show that depoliticized, rational sustainability discourse nonetheless has a political role to play in helping to legitimize informal institutional efforts towards energy policy change.