Innovative Cooling Solutions for High Intensity Solar Applications

Abstract This study presents a comparative experimental analysis of passive and active cooling strategies for thermal management in HCPV modules, focusing on the integration of silver-based nanofluids. The analysis focuses on the use of finned heat sinks and microchannel heat exchangers, employing silver nanofluids as working fluids to improve the thermal and electrical efficiency of these systems under high solar intensity conditions. Two cooling configurations were evaluated: a finned aluminum heat sink (passive) and a microchannel heat exchanger (active), tested under both laboratory and real outdoor conditions. The active system was assessed using distilled water, a water-ethylene glycol mixture, and silver nanofluids, with and without polyvinylpyrrolidone (PVP) stabilization. Results show that while passive cooling offers mechanical simplicity, it fails to effectively dissipate heat under high irradiance, with thermal resistance exceeding 3 °C/W and peak cell temperatures above 66 °C. In contrast, the active microchannel system significantly improved thermal regulation, reducing cell temperatures by more than 17 °C and increasing electrical efficiency up to 29.64%. The use of silver nanofluids further enhanced heat transfer performance, lowering thermal resistance by up to 18.3% and achieving favorable thermohydraulic characteristics. These findings demonstrate that nanofluid-enhanced active cooling systems represent a promising pathway to improve the thermal and electrical performance of HCPV modules, offering scalable and efficient solutions for next-generation solar energy technologies.