Optical properties optimization of plasmonic nanofluid to enhance the performance of spectral splitting photovoltaic/thermal systems

Abstract

Over the past few years, a growing interest has surfaced about the PV/T systems based on nanofluid filter. Some palsmonic nanofluids including Ag, Au and Cu nanoparticles are proposed as the optical filter of PV/T system. To identify the best nanofluid parameters for Si and GaAs solar cell, an optical model of the nanofluids based on Mie scattering theory and Lambert Beer law are developed. Results show that the absorption peak of Ag nanoparticle displays a red-shift trend with the increase of particle diameter and refractive index of base fluid. Adjusting the optical path-length is one efficient way to regulate the optical properties. A maximum merit function (MF) of 1.375 can be achieved for Si cells when Ag/propylene glycol (PG)+CoSO4 nanofluid is used as the optical filter with nanoparticle diameter of 20 nm, concentration of 20 mg/L and optical path-length of 22 mm. The investigation of the best Ag nanofluid filter for GaAs cells reveals that PG base fluid with Ag nanoparticle diameter of 20 nm, concentration of 1 mg/L and optical path-length of 60 mm can achieve a MF value of 1.342. The optimized MF values for Cu and Au nanofluids are slight higher than that for Ag nanofluid.