Multiphysics analysis and optimization of a novel concentrated photovoltaic thermal system utilizing nanoparticle-enhanced spectral filters

Nanoparticle-enhanced liquid filters in concentrating photovoltaic-thermal systems still fall short of ideal spectral selectivity, limiting full utilization of the solar spectrum. This study proposes a compact architecture that simultaneously tunes spectral performance and manages heat through a hybrid cooling strategy: a nanoparticle liquid filter for spectral control, a phase change material layer beneath the solar cell for latent heat buffering, and an actively cooled spiral serpentine coil embedded in this layer to sustain continuous heat removal. A transient, three-dimensional multiphysics model is developed to resolve the coupled optical, thermal, and electrical performance under a concentration ratio of 10. The analysis explores liquid filter thicknesses (2.5–10 mm) and silver nanoparticle volume fractions (40–120 ppm). Further, response surface methodology is used to examine how broadband optical properties and thermophysical characteristics of silver, titanium dioxide, and zinc oxide nanofluids over 40–200 ppm shape key performance indicators. Increasing filter thickness from 2.5 to 10 mm enhances primary electrical power and the merit function by 107.4 %, raises electrical efficiency by 118 %, and increases total thermal efficiency by 105.6 %. A concentration of 120 ppm silver nanoparticles improves thermal stability, lowering the cell temperature by 11 K and increasing filter heat gain by 11 %, but also reduces primary power by 3.8 % and raises the ratio of filter pumping power to electrical output by 65.8 %. The optimal design therefore coordinates nanoparticle type, concentration, and band-targeted optics to balance thermal recovery against preservation of electrical performance.