Recent advancement in hybrid nanofluids used in flat plate solar collectors and future prospects

Hybrid nanofluids are developed by combining conventional fluids with various nanoparticles in specific proportions. This study gathers and analyses recent research published between 2020 and 2024 on the application of hybrid nanofluids in solar collector energy systems. It examines the types of nanoparticles, nanoparticle loading, and system design. The findings demonstrate that the performance of flat plate solar collectors (FPSCs) can be significantly enhanced by employing hybrid nanofluids. With a maximum friction factor of 1.14 times that of water, the Nusselt number (Nu) increased by 21.24% at a 0.16% nanoparticle loading. At 0.3 vol.% nanoparticle concentration and 60ºC, increases in Nu, heat convection, and friction factors were observed at 18.7, 39.33, and 19%, respectively. The exergy performance of the panel improved by 40.5, 36.9, 33.2, and 29.6% with hybrid nanofluids at concentrations of 0.3, 0.2, 0.1 and 0.05 vol.% and Reynolds numbers (Re) of 1414, 1674, 1774, and 1892, respectively. This study offers several recommendations to further enhance the overall performance of FPSCs and maximise energy absorption, promoting broader adoption of hybrid nanofluids.