Inconsistent phenomenon of thermoelectric load resistance for photovoltaic-thermoelectric module

Combing PV with Thermoelectric (TE) would be dominant because it can employ the solar fully spectrum to produce electricity. But the TE efficiency is significantly lower than PV efficiency and the coupling effect between them will limit the performance of PV and TE. The analyze and comparison on the different characteristics among the hybrid module, the PV alone and TE alone is significant to obtain the highest the electrical efficiency. In this paper, the attention was paid to the inconsistent phenomenon of thermoelectric load resistance for photovoltaic-thermoelectric modules. The model of PV-TE was built and verified based on two types of PV cells. The load resistance of TE for the maximum power output was also analyzed under different working conditions for the TE alone, TE in the PV-TE and PV-TE. The results showed that the load resistance of TE for the maximum power output of the TE alone, TE in the PV-TE and PV-TE are all different. For example, the PV-TE module based on the c-Si cell attains its peak value at the load electrical resistance of TE of 0.75 Omega, while the internal electrical resistance of the TE is 0.47 Omega. The PV-TE module based on the GaAs cell shows a maximum efficiency of PV-TE with a load resistance of approximately 1.6 Omega, while the internal electrical resistance of the TE is 2.0 Omega. Referring to the load resistance of TE alone is not suitable for PV-TE maximum power output. In addition, the TE maximum power output does not correspond to the PV-TE maximum power output since the TE load resistances in these two conditions are also different. The study will provide the reference for attaining the correct load resistance for the actual maximum power output of PV-TE module.