Ways to improve the components of a high-temperature silicon-germanium thermoelectric module with radial-annular geometry of thermoelements for use in space nuclear power systems with specific heat fluxes 30–70 W/cm2 at temperatures ∼1200 K are presented. Certain structural elements, which make a thermoelectric converter realistic, such as an electrical insulation unit and a thermojunction which damps stresses, have been developed. The reasons for the losses of thermoelectric efficiency in previously developed thermoelectric modules based on a silicon-germanium alloy are analyzed. The processes responsible for the degradation of thermoelectric modules and determining their service life are determined.Preliminary experiments show that all ways enumerated for lowering the losses and increasing the stability of thermoelectric modules consisting of silicon-germanium alloy are realizable. 7 references.