  The transport coefficients of disordered media are analyzed using direct
numerical simulation and effective medium theory. The results indicate a range
of materials parameters for which disorder leads to an enhanced power factor.
This increase in power factor is generally not accompanied by an increase in
the figure of merit $ZT$, however. It is also found that the effective
electrical conductivity and electronic contribution to the thermal conductivity
are not generally proportional to each other in the presence of disorder.
