Exergy analysis has gained significance in analysing thermal energy systems as it locates and quantifies the irreversibilities in the system. This paper investigates the thermoelectric heat pump systems through exergy analysis. Four thermodynamic models of the thermoelectric heat pump considering the internal and external irreversibilities are developed and analysed in MATLAB Simulink environment with temperature dependent material properties for various operating temperatures. Moreover, analytical expressions for exergy efficiency and irreversibilities for the thermoelectric heat pump are derived. The results show that the exergy efficiency of the thermoelectric heat pump increases with increase in Delta Th. For a typical operating condition in an irreversible thermoelectric heat pump with 31 thermocouples and when T-H and T-C of 313K and 303 K respectively, the maximum energy and exergy efficiency obtained are 4.01 and 12.81% at same optimum current of 5.55A. The results also show that the effect of internal irreversibilities is more pronounced than the external irreversibilities in the performance of the thermoelectric heat pump. The effects of irreversible heat transfer and contact retistance in the exergy efficiency are also studied. This study will be helpful in designing the actual thermoelectric heat pump systems. (C) 2015 Elsevier Ltd. All rights reserved.