Department of Energy Technology, Aalborg University, DK 9220 Denmark
This study considers hybrid model of thermoelectric generators (TEGs) with photovoltaics cells (PVs). Solar cells combined with thermoelectric devices have been attractive technologies due to the advantage of reliability, silent operation, and absence of moving parts. TEGs can convert part of the waste heat of the PV panels into electricity, adding to the production of the PV panel. To achieve a high efficiency of solar electrical devices, the main challenge traditionally is low efficiency of power conversion. Solar irradiation increases temperature of the PV cell, causing the efficiency to decrease. On the other hand, integration of the TEG and a proper heat exchanger can enhance the hybrid module efficiency due to converting a fraction of heat generated by PV into electricity.
This study estimates the solar energy conversion efficiency of the hybrid model compared to the available commercial PV cells. Various crucial effects such as solar radiation and coolant on the PV cell due to wind velocity are considered to simulate real ambient conditions on performance of the hybrid model. To avoid of having additional cost for required pumping power, natural convention cooling technology on the cold side of the TEG is examined. The temperature distribution in the hybrid module will be calculated based on a range of heat transfer coefficients and heat flux across the TEG due to solar radiation variation. The power generation by the TEG will be estimated due to created temperature difference on the cold and hot sides of the TEG. In addition, the variation of power generation in the PV cell will be considered to evaluate the overall efficiency of the module. The results also illustrate the effect of reflection on the PV cell to the ambient for solar radiation variation during sample days.
