In-Field Assessment of Soiling Effects on a Floating Photovoltaic System in a Humid Subtropical Urban Area

Floating photovoltaic (FPV) systems provide an alternative to land-based PV by deploying modules on reservoirs and other water bodies, using underutilized surfaces and benefiting from water-mediated passive cooling that mitigates heat-related efficiency losses. Nevertheless, important knowledge gaps remain, particularly at utility scale. In this study, we analyze soiling at a 7 MWp FPV plant (10,500 modules rated at 665W) operating in a humid subtropical urban environment. We quantify how cleaning frequency affects module-level plane-of-array (POA) irradiation and assess the feasibility of using reservoir water for cleaning. Modules cleaned monthly recorded up to 6.27% higher POA irradiation than those cleaned less frequently.