A global design approach for thermoelectric harvesting system

Energy harvesting is one of the main concerns of our modern society. A huge amount of energy is wasted in industrial plants as low grade heat. Thermoelectricity is one promising way to partly harvest this heat. However, the design of large-scale conversion systems has to be considered carefully in order to optimise the conversion ratio and operating conditions. We report a design method for multi-objective optimisation adapted to large conversion systems operating in industrial conditions. Particularly, it is demonstrated that the decreasing temperature of the hot source along the heat exchanger functionalised with thermoelectric generators has a large influence on the optimisation of the geometry of the conversion module. The influence of the heat transfer from the hot and cold sources to the thermoelectric conversion module is also a critical parameter that dictates the operating conditions. Several solutions for heat concentration has been modelled and experimentally validated. They lead to a large increase of the conversion efficiency.