Numerical evaluation of a bio-inspired hybrid nanofluid-based cooling technique for high-efficiency CPVT system

Abstract This work conducts a comprehensive numerical study of a concentrated photovoltaic–thermal (CPVT) system equipped with a V-trough reflector, with the objective of enhancing output power under realistic operating conditions. Water was employed as the cooling medium, and its heat transfer capability was improved by dispersing hybrid Ag–MgO nanoparticles. To further strengthen convective heat removal, a novel bio-inspired turbulator, designed based on the geometric arrangement of hedgehog spines, was introduced into the cooling channel to intensify flow disturbance. The investigation also accounted for the detrimental effects of dust deposition on PV efficiency and evaluated the effectiveness of a SiO₂ nanoparticle-based self-cleaning coating as a mitigation strategy. Optical analysis of the reflector–PV configuration was performed using SolTrace, yielding an optical efficiency of 85.82%. Internal heat generation within the photovoltaic layers was modeled using user-defined functions (UDFs) integrated into the numerical framework. Validation against previously published experimental data demonstrated excellent agreement, confirming the reliability of the computational model. The results revealed that the V-trough reflector increased CO₂ mitigation by 56.47%, although it caused a 6.4% reduction in electrical efficiency. Employing hybrid nanofluid cooling significantly enhanced the total power output, achieving a value 5.19 times higher than that of an uncooled conventional PV module. While the reflector alone reduced the overall system efficiency by 6.39%, this reduction was limited to 3.2% when turbulator-assisted cooling was applied. The bio-inspired turbulator decreased the average module temperature by 8.28%, and the use of hybrid nanofluid (with concentration of 0.02) led to a 14.18% improvement in electrical efficiency relative to the baseline case. Further improvement was achieved by increasing the coolant inlet velocity, which improved CO₂ mitigation by 1.51%, overall efficiency by 7.42%, temperature uniformity by 41.42%, and useful thermal energy recovery by 11.82%. Dust deposition was found to significantly degrade performance, reducing electrical efficiency by 36.72%. However, the application of the SiO₂-based self-cleaning coating effectively mitigated these losses, enhancing CO₂ mitigation by 27.96%, overall efficiency by 13.71%, and total power output by 8.4%. In summary, this study proposes an integrated CPVT configuration that simultaneously incorporates optical concentration, hybrid nanofluid cooling, bio-inspired flow disturbance enhancement, and anti-soiling surface treatment.