  We revisit the optimal performance of a thermoelectric generator within the
endoreversible approximation, while imposing a finite physical dimensions
constraint (FPDC) in the form of a fixed total area of the heat exchangers. Our
analysis is based on the linear-irreversible law for heat transfer between the
reservoir and the working medium, in contrast to Newton's law usually assumed
in literature. The optimization of power output is performed with respect to
the thermoelectric current as well as the fractional area of the heat
exchangers. We describe two alternate designs for allocating optimal areas to
the heat exchangers. Interestingly, for each design, the use of
linear-irreversible law yields the efficiency at maximum power in the
well-known form, $2\eta_{\rm C}^{}/ (4-\eta_{\rm C}^{})$, earlier obtained for
the case of thermoelectric generator under exoreversible approximation, i.e.
assuming only the internal irreversibility due to Joule heating. On the other
hand, the use of Newton's law yields Curzon-Ahlborn efficiency.
