  We consider theoretically a wide graphene ribbon, that on both ends is
attached to electronic reservoirs which generally have different temperatures.
The graphene ribbon is assumed to be deposited on a substrate, that leads to a
spin-orbit coupling of Rashba type. We calculate the thermally induced charge
current in the ballistic transport regime as well as the thermoelectric voltage
(Seebeck effect). Apart from this, we also consider thermally induced spin
current and spin polarization of the graphene ribbon. The spin currents are
shown to have generally two components; one parallel to the temperature
gradient and the other one perpendicular to this gradient. The latter
corresponds to the spin current due to the spin Nernst effect. Additionally, we
also consider the heat current between the reservoirs due to transfer of
electrons.
