Analysis of precarity has offered a critique of labour market experiences and politically induced conditions of work, housing, migration, or essential services. This paper develops an infrastructural politics of precarity by analysing energy as a critical sphere of social and ecological reproduction. We employ precarity to understand how gendered and racialised vulnerability to energy deprivation is induced through political processes. In turn, analysis of energy illustrates socio-material processes of precarity, produced and contested through infrastructure. Our argument is developed through scalar analysis of energy precarity in urban South Africa, a country that complicates a North-South framing of debates on both precarity and energy. We demonstrate how energy precarity can be reproduced or destabilised through: social and material relations of housing, tenure, labour and infrastructure; the formation of gendered and racialized energy subjects; and resistance and everyday practices. We conclude that analysis of infrastructure provides insights on how precarity is contested as a shared condition and on the prospect of systemic change through struggles over distribution and production.