Effects of Varying Volume Fractions of SiO2 and Al2O3 on the Performance of Concentrated Photovoltaic System

• Published in: Sustainability Vol. 15; no. 10; p. 8125
• Main Authors: Asim, Muhammad, Tahir, Muhammad Hanzla, Kanwal, Ammara, Riaz, Fahid, Amjad, Muhammad, Khalid, Aamna, Abbas, Muhammad Mujtaba, Ahmad, Ashfaq, Kalam, Mohammad Abul
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 17.05.2023
• Subjects: Aluminum oxide; Case studies; Climatic conditions; Cooling; Efficiency; Flow rates; Fractions; Heat exchangers; Heat sinks; Heat transfer; High temperature; Mass flow rate; Microchannels; Nanofluids; Nanoparticles; Payback periods; Photovoltaic cells; Photovoltaics; Power plants; Reynolds number; Silicon carbide; Silicon dioxide; Solar cells; Sun; Surface temperature; Sustainability; Temperature; Temperature profiles; Thermal energy; Working fluids
• ISSN: 2071-1050; 2071-1050
• DOI: 10.3390/su15108125

Highly concentrated triple-junction solar cells (HCTJSCs) are cells that have diverse applications for power generation. Their electrical efficiency is almost 45%, which may be increased to 50% by the end of the year 2030. Despite their overwhelming ability to generate power, their efficiency is lower when utilized in a concentrated manner, which introduces a high-temperature surge, leading to a sudden drop in output power. In this study, the efficiency of a 10 mm × 10 mm multijunction solar cell (MJSC) was increased to almost 42% under the climatic conditions in Lahore, Pakistan. Active cooling was selected, where SiO2–water- and Al2O3–water-based nanofluids with varying volume fractions, ranging from 5% to 15% by volume, were used with a 0.001 kg/s mass flow rate. In addition, two- and three-layer microchannel heat sinks (MCHSs) with squared microchannels were designed to perform thermal management. Regarding the concentration ratio, 1500 suns were considered for 15 August at noon, with 805 W/m2 and 110 W/m2 direct and indirect radiation, respectively. A complete model including a triple-junction solar cell and allied assemblies was modeled in Solidworks software, followed by temperature profile generation in steady-state thermal analyses (SSTA). Thereafter, a coupling of SSTA and Ansys Fluent was made, in combination with the thermal management of the entire model, where the temperature of the TJSC was found to be 991 °C without active cooling, resulting in a decrease in electrical output. At 0.001 kg/s, the optimum average surface temperature (44.5 °C), electrical efficiency (41.97%), and temperature uniformity (16.47 °C) were achieved in the of MJSC with SiO2–water nanofluid with three layers of MCHS at a 15% volume fraction. Furthermore, the average outlet temperature of the Al2O3–water nanofluid at all volume fractions was high, between 29.53 °C and 31.83 °C, using the two-layer configuration. For the three-layer arrangement, the input and output temperatures of the working fluid were found to be the same at 25 °C.