Multi-Criteria Optimisation of Vortex Generators on Building Rooftop PV and Wind Hybrid System: Balancing Dust Removal Efficiency and Wind Power Potential

Photovoltaic panels can benefit from passive dust removal using Vortex Generators (VGs). However, micro-wind turbines mounted on roofs are affected by turbulence induced by VG shear stress and vortices. This study aims to optimise VGs and pitched roof design parameters to balance dust removal and wind-power-potential. The hybrid Taguchi/TOPSIS/CFD technique was employed to define the influence of parameters and optimal design combinations on the performance of a hybrid rooftop solar-wind system. Performance metrics included dust Deposition Rate (DR), dimensionless wind Power Density (PD), and the unacceptable reference turbulence-intensity area ratio (URAR). Optimal results were obtained with a PV inclination of 10°, a 60 mm air channel depth, a 40 mm VG chord length, a 15° VG angle of incidence, and a 60 mm VG height. A DR of 1.048%, a PD of 0.889, and an URAR of 15.295% were achieved with this combination, effectively balancing dust reduction and wind power generation. The optimal scenario increased the TOPSIS score by 0.366 compared to the initial case without VGs. A maximum difference of 0.498% was observed between predicted and simulated TOPSIS scores. It was determined that the PV inclination angle was the most influential factor. CFD analysis shows that VG contraction creates a wind-blocking effect, increasing turbulence intensity and reducing wind-energy potential. Although VG installation alters particle distribution on PV panels, it does not significantly reduce DR, highlighting the requirement to consider these effects in dust deposition studies. This research supports the design and optimisation of VG-installed PV systems on pitched roofs.