  We investigate thermopower and thermoelectric coefficient of nano-granular
materials at large tunneling conductance between the grains, g_{T} >> 1. We
show that at intermediate temperatures, T >= g_{T}\delta, where \delta is the
mean energy level spacing for a single grain, electron-electron interaction
leads to an increase of the thermopower with decreasing grain size. We discuss
our results in the light of new types of thermoelectric materials and present
the behavior of the figure of merit depending on system parameters.
