To understand what a thermoelectric generator is, a basic understanding of a thermoelectric module is necessary. A typical single stage module consists of two ceramic plates with p- and n-type semiconductor material between the plates. A thermoelectric module is a solid-state heat pump that moves heat from one place to another when a DC current is applied. Depending on the polarity of the current, an object can either be heated or cooled. Just as the application of the DC current creates a temperature difference from one side to the other, the application of a temperature difference can generate a Direct Current to produce power. A higher temperature difference generates more power. The process of generating power from this difference in temperature using a thermoelectric device is called thermoelectric power generation.