  The Seebeck-driven transverse thermoelectric generation in
magnetic/thermoelectric hybrid materials (STTG) has been investigated in
all-bulk hybrid materials. The transverse thermopower in a ferromagnetic
Co$_2$MnGa/thermoelectric $n$-type Si hybrid bulk material with the adjusted
dimensions reaches 16.0 $\mu$V/K at room temperature with the aid of the STTG
contribution, which is much larger than the anomalous Nernst coefficient of the
Co$_2$MnGa slab (6.8 $\mu$V/K). Although this transverse thermopower is smaller
than the value for previously reported thin-film-based hybrid materials, the
hybrid bulk materials exhibit much larger electrical power owing to their small
internal resistance. This demonstration confirms the validity of STTG in bulk
materials and clarifies its potential as a thermal energy harvester.
