2Haarare Institute of Technology, Zimbabwe
Abstract
The influence of installation and environmental parameters on dust particle deposition behavior on solar photovoltaic collectors were investigated using Computational Fluid Dynamics (CFD) simulation. Parameters including tilt, height of installation, dust particle size and wind speed were investigated. Modeling of wind flow on the building and the photovoltaic array was achieved using the Shear Stress Transport k-ω turbulence model. The discrete phase model was adopted for dust motion prediction and a model was developed to assess the impact of dust accumulation on the performance of the photovoltaic array. The study revealed that rooftop installations have less dust deposition unlike the ground-mounted installations. The wind flow characteristics on rooftop installations are greatly affected by the building while on ground mounted installations wind flow is only influenced by the tilt of the solar photovoltaic collector. Different tilt angles, wind speeds and particle sizes had different deposition characteristics. The lower impact velocities experienced on ground mounted Photovoltaic (PV) arrays resulted in more deposition for smaller sized (10μm) dust particles compared to the larger sized (50μm and 150μm) particles. On rooftop installations, dust particle size of 150μm had the most deposition at a velocity of 5m/s and hence it resulted in a 22.61% reduction in solar photovoltaic efficiency while the least reduction in efficiency of 1.32% was recorded at 15m/s and 10μm size dust particles. The tilt angles of 0o and 22.5o had large sized turbulent eddies compared to the tilt of 45o. The study revealed that ground mounted photovoltaic arrays had more dust deposition compared to rooftop mounted photovoltaics.