Toward Heat Energy Harvesting using Pyroelectric Material

This study investigates the feasibility of heat energy harvesting using pyroelectric effect. In order to improve the effectiveness of the energy conversion from heat to electricity, the synchronized switch harvesting on inductor (SSHI) (Guyomar et al., 2005) technique is experimentally tested, which has already proved its quality in electromechanical conversion. For several amplitude variations of temperature from 0.5 to 8.0 K, the conversion efficiency is found about 0.02% of Carnot thermodynamic cycle with a standard interface. Under the same heating conditions, experimental results show that the SSHI technique increases the converted energy by a factor which is about 2.5 times of the standard interface, with which the efficiency practically becomes 0.05% of Carnot thermodynamic cycle. In this case, the produced electrical power for temperature amplitude 7 K is more than 0.3 mW for an energy harvesting device composed of 8 g of active material. The main power limitation is due to temperature frequency. Low speed of heat transfer makes it difficult to obtain fast temperature variations with large amplitude.