Many tropical islands aim at developing a greener self-sufficient energy production systems based on renewableenergy, notably solar-generated electricity. This work explores the mean diurnal and annual solar cycles over LaRéunion island (southwest Indian Ocean: 21°S, 55.5°E), and their spatial behavior, using the Solar surfAceRAdiation Heliosat – East (SARAH-E) satellite-derived data at high spatial (0.05° × 0.05°) and time (hourly)resolutions over period 1999–2016. Comparisons of the SARAH-E data with ground-based measurements overthe period 2011–2015 show differences of ~15% for diurnal-seasonal variations. The solar resource over theisland displays strong spatial variability, with differences larger than 100 W m−2 between coastal and mountainouszones. The mean solar resource is lower on the island than on the nearby sea by ~20%. The strongestinteractions between the diurnal and annual cycles are found at the windward mid-slopes and near the activevolcano, in line with the well-known cloud processes encountered there. A clustering of solar zones, based ondiurnal-seasonal cycles, structures the island into a dipole that opposes the western to the eastern side of theisland.