Analysis of Energy Performance of Nanofluid-Based Spectral Splitting Photovoltaic/Thermal Collectors of Different Designs

Nanofluid-based spectral splitting photovoltaic/thermal (SSPV/T) system is an emerging means of achieving full-spectrum utilization of solar energy. In this paper, one-dimension models for nanofluid-based spectral splitting photovoltaic/thermal collectors designs are presented and validated by the experimental results. The energy performance of SSPV/T collectors of different structural designs is analyzed and compared with conventional collectors. The results show that for SSPV/T or conventional photovoltaic/thermal collectors, an insulated cover is very important, especially for thermal efficiency. The thermal efficiency of Design C (cover-insulated SSPV/T) is nearly four times of Design A (non-cover-insulated SSPV/T), while the electrical efficiency is only reduced by 0.7%. The analysis indicates that at present technologies, the spectral splitting PV/T collectors have no obvious advantages than conventional PV/T collectors whether for non-cover-insulated or cover-insulated PV/T collectors. Additionally, Design F (conventional cover-insulated PV/T with low-e coating) performs better than Design C (cover-insulated SSPV/T), low-e coating (high transmittance) is very promising in improving PV/T thermal efficiency.