High-resolution mapping reveals a profound gap between existing rooftop solar deployment and potential in Africa.

Rooftop photovoltaics offer a flexible and scalable pathway for expanding electricity access and advancing power system transitions in Africa. However, spatially explicit tracking of rooftop photovoltaic installations at a continental scale remains a critical bottleneck, hindering efforts to characterize deployment patterns, assess regional untapped potential, and inform investment decisions. Here, we used satellite imagery and a U-Net semantic segmentation model to construct a geospatial database of rooftop photovoltaic installations across Africa. Results showed that total rooftop photovoltaic installations have reached 3.37 GW, with capacity predominantly concentrated in South Africa (∼71%). Strikingly, existing installations represented less than 1% of the continent's total capacity potential. Moreover, the analysis revealed that rooftop photovoltaic deployment is primarily driven by local electricity demand, with solar irradiance playing a relatively limited role. These findings offer an empirical foundation for optimizing renewable energy policy and guiding infrastructure planning in Africa.