  In this article we review aspects of charge and heat transport in interacting
quantum dots and molecular junctions under stationary and time-dependent
non-equilibrium conditions due to finite electrical and thermal bias. In
particular, we discuss how a discrete level spectrum can be beneficial for
thermoelectric applications, and investigate the detrimental effects of
molecular vibrations on the efficiency of a molecular quantum dot as an energy
converter. In addition, we consider the effects of a slow time-dependent
modulation of applied voltages on the transport properties of a quantum dot and
show how this can be used as a spectroscopic tool complementary to standard
dc-measurements. Finally, we combine time-dependent driving with
thermoelectrics in a double-quantum dot system - a nanoscale analogue of a
cyclic heat engine - and discuss its operation and the main limitations to its
performance.
