Performance Analysis of Stacked Photovoltaic-Thermoelectric Generator Using Mathematical Thermal-Electrical Model

This paper proposes an electrical-thermal model to evaluate the performance of often proposed PV-TEG stacked systems where the thermoelectric generator device is mounted on the back side of the PV cell. This way, the heat generated by the PV cell is collected by the surface area of the heat collector. The heat sink has been settled at the bottom of the thermoelectric generator device. Investigations were performed at different light concentration levels of 1, 2, 3, 4 and 5 suns. The efficiency of the thermoelectric generator increases with the light concentration due to the increasing in the temperature difference across its terminals. The results showed that the stacked system efficiency is decreasing with the increase of light concentration level and still lower than the efficiency of standalone illuminated PV cell. This is due to the high junction temperature which results in a decrease in the solar cell efficiency where the TEG device is still not able to compensate the decrease in the efficiency of the PV cell. It can be concluded that thermal coupling between the two devices has to be avoided to enable both devices to operate efficiently at their respective optimal operational temperatures.