Increasing research efforts have been devoted to renewable energy owing to the large energy consumption in recent years. Comparing to fossil fuel, renewable energy with the advantages of reduced carbon emission and secure long-term energy supply is more mandatory for the sustainable development of the world. Thermoelectric generator, which works based on thermoelectric effect, is capable of converting waste heat into electricity with a temperature difference relative to environmental temperature. Many studies have demonstrated that nanomaterials can enhance their ZT values by suppressing the thermal conductivity compare to their bulk counterparts. In our research, we developed thin, light-weight, and flexible thermoelectric generators based on the nanocomposites of inorganic (Te, Ag₂Te, MoS₂, and Graphene) nanomaterials and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). These properties result in those nanocomposites are good candidates to fabricate thermoelectric generators to harvest tiny-scale thermal energy and show their potential to be applied in the collection of heat energy from vehicles, aircrafts, and power plants.