A thermoelectric generator is one of the key candidates for the renewable energy devices, which directly converts waste heat into electricity. The wide applications of the device are suppressed because of the device low efficiency. In this paper, a new innovative design of the thermoelectric generator incorporating the extended pin with segmented pin configuration is introduced. The new design allows the device operating at two different cold junction temperatures. The maximum efficiency and the output power for the innovative design of thermoelectric device are formulated. The performance of the thermoelectric device is evaluated using the operating parameters such as the hot and cold junction temperatures in terms of temperature ratio, and external load resistance ratio. The reveals that the innovative design improves the maximum efficiency and output power of the thermoelectric generator. Increasing the cold junction temperature difference increases the device maximum efficiency by 3.5-6.2%. The maximum device output power and maximum thermal efficiency occur at different values of external load parameter. However, the reduction in the efficiency is considerably small for the external load parameter maximizing the device output work. (C) 2016 Elsevier Ltd. All rights reserved.