Current efforts to change patterns of energy demand tend to target people as discrete and isolated individuals. In so doing, they ignore the fact that energy use occurs in places such as homes, workplaces and communities in which complex webs of social relations already exist. Here, we argue that more attention should be paid to how people's social relations influence energy demand. We review recent qualitative research to show how social relations shape how much energy people use, when and where they use it, as well as how they respond to interventions. We propose a typology that identifies three types of social relation as especially significant: those with family and friends, with agencies and communities, and those associated with social identities. We show how a focus on social relations can generate new forms of policy and intervention in efforts to build more just and sustainable energy futures. Humans are social animals: our relationships shape our experiences, decisions and actions. Energy demand is no exception: how we consume energy is shaped by relationships of conflict, consensus, collaboration, companionship, solidarity and oppression with our fellow human beings. When people talk about using energy at home, work or in their communities, they also talk about their relationships with others to explain how and why they consume in the ways they do. Stories of teenagers leaving the lights on, or colleagues being perpetually cold in the office are familiar to us all. It follows that attempts to change patterns of energy demand, to make them more flexible 1 , more just 2,3 , or to help decarbonise energy systems 4,5 depend fundamentally on social relations. Relational sociology characterises how people act as structured by the situations they are in, others involved in those situations, and their relations with those others 6. Social relations are therefore seen as shaping, and being shaped by interactions (giving these meaning and significance), reproduced by practices, and important in processes of identity building 6-8. Social relations shift over time, and the history and expected future of a relationship impact on how it is experienced in the present 6. People have patterns of social relations, which differ between societies, groups of people and individuals, and which impact on their access to resources. There is a distinction between 'micro' social relationships in daily life (those with parents, friends or teachers) and 'macro' social relationships (such as relationships of class, gender, or belief) 8 , but these intersect and overlap in people's lives. To help illustrate the multiple ways that social relations shape energy demand, Boxes 1 and 2 provide two vignettes drawn from our own research that show how social relations have