  Thermoelectric effects in normal metals and superconductors are usually very
small due to the presence of electron-hole symmetry. Here, we show that
superconducting junctions brought out of equilibrium manifest a sizable bipolar
thermoelectric effect that stems from a strong violation of the detailed
balance. To fully control the effect, we consider a thermally biased SIS'IS
junction where the capacitance of the central S' region is small enough to
establish a Coulomb blockade regime. By exploiting charging effects we are able
to tune the Seebeck voltage, the thermocurrent, and thereby the power output of
this structure, via an external gate. We then analyse the main figures of merit
of bipolar thermoelectricity and we prospect for possible applications.
