Abstract
Concentrator photovoltaic (CPV) systems have displayed an important cost reduction and in the next few years could offer a competitive cost advantage compared to that of flat plate PV systems. Such CPV systems require some cooling methods to overcome high operating temperatures, which reduces their efficiency significantly. On the other hand, thermoelectric generators (TEG) are devices that convert thermal energy directly to electrical energy, provided that there is a temperature difference between its two faces. A hybrid concentrator photovoltaic/thermal (CPV/T) system is proposed in this work. Such a system uses TEG in a two-fold manner: to passively cool down the CPV cell in order to maintain its power conversion efficiency in such high temperature conditions, and to use the accumulated thermal energy to generate electrical energy, which is added to the system's total power output. Two types of solar cells were investigated, namely, Ga0.35In0.65P/Ga0.83In0.17As with efficiency an of 28% at 250X, and a Laser Grooved Buried Contact (LGBC) silicon concentrator PV cell with an efficiency of 18.3% at 40X. These cells are assumed to be coupled with two TEGs of the same type but with a different number of junctions. Experimental results showed that coupling TEG modules to a CPV system could be a useful method for enhancing the overall output power, provided that PV cells are chosen with a low efficiency temperature coefficient and high PV performance. Also, TEG modules have to be chosen with a high figure of merit. Moreover, the operating optical concentration ratio, as well as the covered area of the TEG, have to be optimized in order to maximize the total system output.