Waste heat recycling of high-power lighting through chips on thermoelectric generator

Abstract A waste heat is inevitably generated in high-power lighting due to the limited efficiency of light-emitting diode (LED) chips and the non-radiative transition of phosphors. In this work, we proposed an integrated module of LED chips on thermoelectric generator (TEG) for the waste heat recycling of high-power lighting. The multi-chips were directly bonded on the hot side of TEG for heat conduction. The chip powers and temperature distribution of chips-on-TEG were investigated under different chip currents, and their output voltage, current, and power were measured. When the chip current increases from 0.4 to 1.4 A, the heat power increases from 1.7 to 9.2 W, resulting in a high temperature gradient of 219 °C for the TE elements at the chip current of 1.4 A. This enough heat energy converts to an electric power with an output voltage of 1.23 V. In addition, a low-power indicating lamp was driven by the electricity from three chips-on-TEGs without additional power consumption. Our work opens a good idea to recover the normally wasted heat from high-power lighting, which could be extended for the heat energy harvesting in many power devices.