The kit demonstrates the direct conversion of heat into electrical energy using the Seebeck effect. As in solar cells, electricity is generated directly by processes at the atomic level without moving mechanical parts. The atomic oscillations coupled with heat lead to a gradient in the electron distribution and thus an electrical voltage.
The actual conversion of heat into electric current takes place in the Peltier element. One side of this flat element is thermally connected to a warm water bath via an aluminium L-profile, the other to a cold water bath. Thus, a heat flow of higher temperature is conducted to the Peltier element and a smaller heat flow of lower temperature is conducted away from the Peltier element. The difference between these heat flows corresponds approximately to the electrical energy generated. As long as the temperature difference applied to the Peltier element is greater than about 10 degrees, enough electricity is generated to drive the connected motor with propeller.