High resolution global spatiotemporal assessment of rooftop solar photovoltaics potential for renewable electricity generation

Rooftop solar photovoltaics currently account for 40% of the global solar photovoltaics installed capacity and one-fourth of the total renewable capacity additions in 2018. Yet, only limited information is available on its global potential and associated costs at a high spatiotemporal resolution. Here, we present a high-resolution global assessment of rooftop solar photovoltaics potential using big data, machine learning and geospatial analysis. We analyse 130 million km² of global land surface area to demarcate 0.2 million km² of rooftop area, which together represent 27 PWh yr^-1 of electricity generation potential for costs between 40-280 $ MWh^-1. Out of this, 10 PWh yr^-1 can be realised below 100 $ MWh^-1. The global potential is predominantly spread between Asia (47%), North America (20%) and Europe (13%). The cost of attaining the potential is lowest in India (66 $ MWh^-1) and China (68 $ MWh^-1), with USA (238 $ MWh^-1) and UK (251 $ MWh^-1) representing some of the costliest countries.