How does a thermoelectric generator turn heat directly into electricity?
The ingenuity people used in harnessing waterpower can be seen in this medieval-style mill. The waterwheel is turned by a stream and is connected to a shaft that leads into the building. At the other end of the shaft is a gear. The connection of a series of gears translates the power from the stream to a shaft that drives a millstone, which grinds flour from grain.
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A thermoelectric power generator converts heat directly into electricity through a process known as the Seebeck effect.1
This process relies on the interaction between heat flow and electricity within solid-state materials. The device is configured with a heat source at one end and a heat sink at a lower temperature at the other. This temperature differential drives electrons across a potential difference at the junction of two dissimilar conducting materials.21
Because this method involves no intermediate energy conversion steps—such as the use of steam or gas to drive a turbine—it is classified as direct power conversion. When the circuit is closed, this movement of electrons creates a direct current (DC) that can be used to power electrical equipment. While early devices were limited by the efficiency of available metallic conductors, the development of semiconductor materials significantly improved their performance, making them highly reliable for specialized applications like remote data transmission.213