A process for manufacturing a nanocomposite thermoelectric material having a plurality of nanoparticle inclusions. The process includes determining a material composition to be investigated for the nanocomposite thermoelectric material, the material composition including a conductive bulk material and a nanoparticle material. In addition, a range of surface roughness values for the insulating nanoparticle material that can be obtained using current state of the art manufacturing techniques is determined. Thereafter, a plurality of Seebeck coefficients, electrical resistivity values, thermal conductivity values and figure of merit values as a function of the range of nanoparticle material surface roughness values is calculated. Based on these calculated values, a nanocomposite thermoelectric material composition or ranges of compositions is/are selected and manufactured.