Energy, Exergy, and Techno-Economic Performance of an Enhanced Photovoltaic/Thermal Collector

Abstract

This study experimentally investigates the energy, exergy, and economic performance of an enhanced photovoltaic/thermal (PVT) solar collector using micro-finned tubes, twisted-tape inserts, hybrid nanofluid, and nano-enhanced phase-change material (NPCM). Five collector configurations were tested at mass flow rates ranging from 0.008 to 0.042 kg/s. The best-performing configuration combined micro-finned tubes and twisted-tape inserts with SiC-NPCM and a hybrid nanofluid composed of 0.3 vol.% SiC and 0.3 vol.% Al2O3 dispersed in water. The experimental uncertainty was reported to be within ±3.5%. The optimized configuration achieved a maximum thermal efficiency of 87.5% and a peak useful thermal output of 189 W at a mass flow rate of 0.033 kg/s, corresponding to a 71.8% improvement compared with the baseline system. Active cooling of the photovoltaic back surface also increased the peak electrical power output to 23.5 W. The maximum overall exergy efficiency reached 12.85%, representing a 117.8% improvement compared with the conventional configuration. Although the micro-finned tubes and NPCM accounted for a substantial share of the initial capital cost, operation at a mass flow rate of 0.024 kg/s provided a favorable compromise between performance and cost, reducing the unit energy cost to USD 0.094/kWh while maintaining thermal-storage stability. The results indicate that the proposed hybrid cooling strategy can improve the thermal and thermodynamic performance of PVT collectors, although further validation under outdoor conditions is recommended.