Abstract This study presents a socially sustainable energy system narrative that is based on two pillars: energy sufficiency as the universal energy system goal and the energy-justice-based principles of energy access provision. The constructed narrative provides an operational theoretical foundation for choosing energy provision technologies that can be considered socially sustainable and offers an alternative to prioritizing the cost-minimization mindset. Through a case of household electricity provision in Sub-Saharan Africa, the narrative is applied as a set of theoretical assumptions for energy system modelling. The presented model explores to what extent different combinations of centralized, decentralized, fossil-fuel-based and renewables-based electricity access provision are compatible with the principles of socially sustainable energy system design. Comparing three different scenarios of electricity access provision using centralized and decentralized fossil-fuel-based and renewables-based electricity generation technologies, this study concludes that decentralized and renewables-based electricity generation mixes are associated with higher cost but also with greater social sustainability benefits. By combining a conceptual narrative of socially sustainable energy systems with system dynamics modelling, theoretical work on sustainable energy system development is bridged with the energy system modelling practice. The research design of this study may interest scholars working on the theoretical development of sustainable energy system principles and their application in modelling as well as energy system modellers.