Thermal Energy Harvesting from Small Sources Using Thermoelectric Generators

This paper aims to design, use, and integrate a system based on thermoelectric generators (TEGs). TEGs can convert heat to electricity through the Seebeck effect and vice versa. They have low complexity. These devices denote a nonconventional method of electrical energy generation. The power supplied by TEGs is low, but still can be used in low power applications. The main obstacle to these elements usage is low efficiency, and, for high-power systems, dimensions are exceptionally large. By connecting at least five TEG elements in a series, they can supply a voltage of about 2 to 3V to a boost converter input and lighting some LED strings. The booster converter controller used in this application is the LT1930, with good characteristics. A single dc-dc converter is used to stabilise the voltage, because is cheaper than classic approaches, when a converter is used to maximise the harvested power and another one as a stabiliser. In our experimental setup, the heat source used to supply TEG elements is some candles and the cooling is done by a heat sink. The solution can be industrialised as a product useful in case of electricity shortage or in non-electrified areas.