It is increasingly recognised that the future energy system will be digitalised, and that end-user engagements with this system will be digitally mediated by smart ICT. The digitalisation of the energy system promises significant benefits, but also risks replicating and entrenching persistent inequalities in the ability of households to access adequate energy services. Focusing on a case study of the United Kingdom, this paper explores the links between energy system digitalisation, digital exclusion, and energy poverty, with the wider aim of sketching out a research agenda for understanding the risks, opportunities, and inequalities latent within the transition to a digitalised energy system. Drawing on a review of relevant literatures, the concept of social relations developed by Hargreaves and Middlemiss (2020), and a thematic analysis of a stakeholder workshop, the paper identifies five areas of focus for further research and analysis: 1) the role of financial exclusion and asset affordability in shaping digital inclusion and exclusion, 2) time and temporality, 3) the role of trust in shaping engagements with digital technologies, 4) language, literacy, and communication, and 5) the uneven impacts of digital exclusion on different social groups. The paper concludes with reflections on the practical challenges and implications of pursuing this agenda.