A just energy transition is as much about acknowledging and acting on the socio-material needs of marginalised classes and groups as about informing inclusive and deliberative policy-making towards more equitable energy futures. In democracies, energy social scientists hold a privileged position and special responsibility to do both, thus offering critical support to decision-makers and practitioners. We articulate the challenges and opportunities for energy social scientists to embody solidarity in their research orientation and practices. First, we articulate the need to repoliticise, redemocratise, and negotiate a multiplicity of energy transitions. This includes recognising and engaging with multiple scales and contexts of marginality, repoliticising energy transitions, and addressing contestation and negotiation. Then, we argue that by embracing solidarity in research, energy social scientists can meet these needs in a holistic manner. We provide three principles through which social scientists can embrace solidarity to move energy research towards enhancing just transitions. These include (i) taking direct action and relating in solidarity, (ii) recognising responsibilities and limitations of energy social scientists, and (iii) nurturing a political realist culture of solidarity. In espousing these principles, we articulate solidarity as integral to pragmatic research practices in the face of urgency and rapid energy transitions.