BENCHMARK NUMERICAL SIMULATIONS OF SOLAR THERMOELECTRIC GENERATORS

In this paper, to simplify the design and optimization of thermoelectric generators (TEGs), a three-dimensional numerical model is implemented in a computational finite element simulation environment (COMSOL). The model can take into consideration the Peltier effect, Thomson effect and Seebeck effect inherent to TEGs. In terms of a p-element TEG, many cases are tested to validate the model and good agreement between numerical predications and analytical solutions are achieved. To demonstrate the feasibility of the model, benchmark numerical simulations are carried out for solar thermoelectric generators (STEG) originally proposed by Kraemer et al. (Nature Materials, 10 (2011) 532-538). The results are in good agreement with reported experimental data for a range of STEG configurations and it is shown that the 3D simulations in this work more closely match the 1D simulations in the literature. Parametric studies on the thermal conductivity of the solar absorber indicate that the STEG efficiency significantly increases for small thermal conductivity, but levels off at about 40 W/(m⋅K). Specifically, the STEG efficiency increases only 0.1 % when kabsorber varies from 40 W/(m⋅K) to 1000 W/(m⋅K).