Decarbonization potential of floating solar photovoltaics on lakes worldwide

As climate change intensifies, decarbonizing energy systems is urgent. Floating solar photovoltaics (FPVs) can alleviate land-use pressures and may offer higher efficiencies than ground-mounted PVs, but their global potential remains unclear. This study quantifies energy generation potential for FPVs across more than 1 million lakes and reservoirs worldwide, simulating outputs with the Global Solar Energy Estimator (GSEE) and scaling to a conservative 10% surface coverage (capped at 30 km² per water body). Theoretical global FPV output is 14,906 TWh yr⁻¹. Under feasibility constraints (proximity to population centers, outside protected areas, limited ice cover, and persistence of water bodies), 67,893 sites remain, yielding 1,302 TWh yr⁻¹. FPVs could meet on average 16% of national electricity demand and fully meet or exceed demand in about 3% of countries, offering substantial decarbonization and potential co-benefits for water conservation.