Thermogalvanic cell

[5] This is in contrast to galvanic cells in which electrodes and/or solutions of different compositions provide the electromotive potential.

The electrons flow through the path of least resistance (the outer circuit) making it possible to extract power from the cell.

[5] An essential property of these compounds is that they must be able to undergo redox reactions in order to shuttle electrons from one electrode to the other during the cell operation.

This is an advantage as these cells produce more power the larger the difference between the hot and cold sides.

On the other hand, the liquid salt directly provides the anions and cations necessary for sustainment of a current through the cell.

Studied systems fall in the 400–900 K. Some solid ionic materials that have been employed to construct thermogalvanic cells are AgI, PbCl2 and PbBr2.

The main application of thermogalvanic cells is electricity production under conditions where excess heat is available.

In contrast to the low-temperature solar thermal systems that are used for air or water heating in domestic or commercial buildings, these solar thermal electricity plants operate at high temperatures, requiring both concentrated sunlight and a large collection area, making the Moroccan desert an ideal location.

Thermogalvanic cells can be used to extract a useful quantity of energy from waste heat sources even when the temperature gradient is less than 100C (sometimes only a few tens of degrees).