Thermoelectrics are materials that produce a voltage when subjected to a thermal gradient, and can therefore be used to generate electricity from waste heat. Such materials are set to play an increasingly important role in the development of new energy efficient technologies. However, it is difficult to produce new highly efficient thermoelectrics, as multiple coupled properties (notably electronic and thermal conductivity) need to be optimised simultaneously. In particular, the development of oxide thermoelectrics is desirable due to the physical and chemical stability they offer at very high temperatures. We have synthesised three series of oxide solid solutions that exhibit n-type thermoelectric properties, and propose to use high-resolution powder neutron diffraction (coupled with in-house electron microscopy) to characterise their structures, which are potentially highly complex.