Performance Assessment and Optimization of a Concentrated Triple-Junction Solar Cell Coupled with a Thermoelectric Generator and a New Trimmed Fins Heat Sink

The current numerical analysis presents a novel approach for passive cooling of triple-junction (TJ) solar cells integrated with thermoelectric generator (TEG) by an innovative trimmed fins heat sink. The fins design, length and cutting angle are tailored based on the thermal distribution of the hybrid system. The envisaged configuration enables the extraction of excess heat from the cell and its conversion into secondary power via thermoelectric generator. This enhances the system’s cooling efficiency and power generation while minimizing material usage. Three-dimensional thermo-electric model was developed and simulated at various dimensions and cutting angles of the finned heat sink. Results showed that the new trimmed fins heat sink with a flat base area of 2500 mm2 and fins cutting angle of 44° is ideally compatible for operating the HCPV TJ cell at the highest possible performance while avoiding significantly increasing the system’s weight. This design improves the TJ cell performance, allowing for maximum allowable solar concentration of 205 and 157 suns at 1 m/s compared to 43.5 and 33 suns for the uncooled reference cell at ambient temperatures of 25 and 45°C, respectively. Accordingly, the system was enabled to generate a higher power of 7.89 and 6.03 W/cm2 (based on cell active area), while the uncooled cell is limited to 1.65 and 1.3 W/cm2. The remarkable increase in system efficiency caused by the hybrid cooling system achieved environmental benefits by reducing CO2 emissions by 189.4-ton Co2/yr⋅m2. Finally, Taguchi analysis revealed that the solar incident irradiance concentration ratio has greatest effect on system performance when compared to the other operational variables.