This paper presents a comparative study of two-stage, segmented and conventional thermoelectric generators. A detailed numerical study is performed using COMSOL Multiphysics and finite element method. The effects of thermoelectric leg height ratio, hot and cold side temperatures on the power output of the two-stage thermoelectric generator (TTEG), segmented thermoelectric generator (STEG) and conventional thermoelectric generator (TEG) are studied using three-dimensional numerical models. Results show that the TTEG and STEG provide an increased power output of 14.90% and 21.04% respectively compared to the skutterudite TEG at hot side temperature of 425 â„ƒ. Furthermore, it is found that the STEG is the best performing system studied and it provides an increased power output of 5.34% compared to that of the TTEG at 425 â„ƒ hot side temperature. In addition, results show that the power output of the TTEG and STEG increased respectively by 19.09% and 20.61% as the leg height ratio is increased from 1 to 4 for hot side temperature of 425 â„ƒ. Therefore, thermoelectric leg height ratio optimization is essential for performance enhancement.
Keywords Thermoelectric generator, TTEG, STEG, Finite element method, Leg height