  In the previous paper of Alicki et.al. a model of a solar cell has been
proposed in which the non-periodic source of energy - photon flux - drives the
collective periodic motion of electrons in a form of plasma oscillations.
Subsequently, plasma oscillations are rectified by the p-n junction diode into
the direct current (work). This approach makes a solar cell similar to standard
macroscopic heat motors or turbines which always contain two heat baths, the
working medium and the periodically moving piston or rotor. Here, a very
similar model is proposed in order to describe the operation principles of
thermoelectric generators based either on bimetallic or semiconductor p-n
junctions. Again plasma oscillation corresponds to a piston and sunlight is
replaced by a hot bath. The mathematical formalism is based on the Markovian
master equations which can be derived in a rigorous way from the underlying
Hamiltonian models and are consistent with the laws of thermodynamics.
