Sub-Saharan Africa (SSA) faces many challenges: two-thirds of the world's extreme poor population; a shrinking economy because of commodity price declines and the COVID-19 pandemic; widespread energy poverty; and climate variability that is disrupting agrarian livelihoods and stirring conflict over natural resources. Climate change threatens to exacerbate these through further disruption of the physical environment, and a transition away from the fossil fuels on which many of the region's economies depend. Through their nationally determined contributions (NDC) to the Paris Agreement, all SSA countries committed to the increased utilisation of intermittent renewable energy sources (IRES) to tackle the twin challenges of energy poverty—which limits economic development—and climate change. There is a dearth of analysis on the nature of sustainable energy transition(s) necessary to deliver these NDCs, especially given the limited financial and technical resources of SSA. Using Nigeria as a case study, this study seeks to address this gap by determining the power system transitions required to deliver NDCs alongside universal energy access in SSA by 2050; their financial and policy implications; and the barriers and opportunities that they present to sustainable development efforts. We find that Nigeria can deliver its NDCs with no added cost implications, thereby debunking the prevalent view that climate change mitigation is too costly to pursue in SSA. Furthermore, we find that the higher availability and dispatchability of fossil fuel generation makes it critical for the rapid scale-up of energy supply; thus, entirely leapfrogging carbon-intensive development will prove costly to SSA. Finally, owing to the limited cost reductions that IRES have experienced in SSA, delivering NDCs through the deployment of decentralised IRES systems proves more expensive than using conventional generation. The distributed nature of IRES however means that they can democratise energy investment and job creation, thus facilitating the equitable sharing of economic resources which is crucial to conflict prevention in the fragile socio-political landscapes that pervade the region.