Peltier effect: a standalone construct

French physicist Jean Charles Athanase Peltier reported in 1834, in Nouvelles expériences sur la caloricité des courants électriques, that passing an electric current across the junction of two different conductors changes the junction's temperature, heating it or cooling it depending on the direction of the current. This is now called the Peltier effect: a reversible thermoelectric phenomenon in which an electric current carries heat across a junction of two dissimilar materials, so one junction cools while the other warms, distinct from the irreversible resistive heating (Joule heating) that occurs throughout any current-carrying conductor. It is the counterpart of the Seebeck effect, in which a temperature difference across such a junction instead produces a voltage, and modern reviews describe how the two, together with the related Thomson effect, form the basis of solid-state thermoelectric devices. Because it moves heat with no moving parts, refrigerant, or compressor, the Peltier effect is the operating principle of the thermoelectric coolers used to chill electronics, laser diodes, and portable coolers, and the same junction run in reverse under a heat flow instead generates electricity.[1][2][3]

Unit

A reversible thermoelectric phenomenon: heat absorbed or released at a junction, proportional to the electric current and to the Peltier coefficient of the material pair

Recovery means

Not applicable

Measured by

Quantified as the Peltier coefficient, the heat absorbed or released at the junction per unit current (in volts), measured calorimetrically or inferred from the pair's Seebeck coefficient and absolute temperature