Use of thermoelectric generators to harvest energy from motor vehicle brake discs

Abstract

The challenge of reducing vehicle energy consumption and greenhouse gas emissions has become a major orientation of automotive industry research throughout the world. Improving and optimizing power consumption by electric vehicles is of special concern. A novel use of thermoelectric generators in vehicle braking is presented. Thermal analysis of brake pads and discs using finite elements was applied to evaluate the energy potentially available in the form of heat produced by the friction involved in braking. We present stimulations of disc heating during and after braking at three ambient temperatures and reflect on the possibilities of energy recovery in warm as well as cold climates. The results show that although the yield of electrical energy from typical thermoelectric generators is about 0.3% of the total thermal energy associated with braking, at least 4 W can be made available, enough to power on-board instrumentation and vehicle devices and thereby improve the energy efficiency of motor vehicles.