Designing high efficiency segmented thermoelectric generators

Improving the efficiency of thermoelectric devices is critical to their widespread adoption. Here a design methodology, formulated on computational and analytical modeling, derives the optimum efficiency and geometry of segmented Bi2Te3–PbTe Thermoelectric Generators (TEGs) between ≈298 K and ≈623 K (ΔT ≈ 325 K). Comparisons between the different TEG designs, in terms of the electrical load to TEG electrical resistance ratio (m = RL/RTEG), are simplified thanks to the devised maximum efficiency to temperature gradient (βmax = η/ΔT) metric. Quasi-computational results of βmax show that the collective Seebeck coefficient Bi2Te3–PbTe ( α ˜ ) design sustains a higher electrical load in relation to the homogeneous Bi2Te3 and PbTe materials. The average ( α ¯ ) and collective ( α ˜ ) Seebeck coefficient Bi2Te3–PbTe configurations, in comparison to Bi2Te3 and PbTe, exhibit a considerably higher (60–68%) source and sink thermal resistance matching (ΘTEG = ΘHx). The proposed segmented Bi2Te3–PbTe ( α ˜ ) TEG yields a peak efficiency of 5.29% for a ΔT of 324.6 K.