Theoretical efficiency of hybrid solar thermoelectric-photovoltaic generators

This work analyses the potential of hybrid solar thermoelectric photovoltaic generators (HSTEPVGs) through evaluating their efficiency in converting solar power into electricity for a system consisting of a PV cell placed directly on top of a thermoelectric generator. A theoretical model for terrestrial application which includes the possibility of thermal and optical concentrations is reported. As in the case of pure solar thermoelectric generators, an optimal operation temperature also exists for HSTEPVGs determined by the temperature dependences of both the solar cells and the thermoelectric generators. The study reports an efficiency gain of 4%–5% with respect to the sole PV case, especially in the case of optical concentrations which mitigate the solar cell temperature sensitivity. In addition to these interesting results, the work also reveals the major constrains expected for this approach, along with technological challenges especially regarding the optical properties of the device encapsulation and the solar cell degradation.