Particle transport-driven flow dynamics and heat transfer modulation in solar photovoltaic modules: Implications on soiling

Abstract

Wind-swept debris and excessive heating reduce solar photovoltaic efficiency and accelerate panel degradation. For many solar plants in open environments, particle deposition is well-understood to exacerbate efficiency losses by blocking useable light and insulating panel surfaces. However, little is known about particle behavior in multi-panel systems, where complex wakes dominate and alter trajectories. This study examines debris-laden flow within a scaled array of two model solar panels, observing convective cooling and focusing on turbulent inter-panel flow dynamics. Convection is compared between the first and second panels (P1 and P2) for a single inflow velocity at four particle concentrations (ϕv), including a neutrally buoyant particle (i.e. tracer) case and three water droplet cases. Tracers and ϕv>0 concentrations show increased convective heat transfer for P2 compared to P1, while inertial particle presence and increased concentration reduces this improvement from +170% to +90%. Particle image velocimetry surrounding P2 reveals dampened inter-panel wake features for particle-laden flow compared to the tracer case, where diminished mean flow and mean kinetic energy breakdown are observed for the particles due to their inertia. Together, the reduction in comparative convection and dampened wake effects accompanying inertial particle concentration motivates further studies on coupled array physics in debris-filled flow.