The thermoelectric generator (TEG) has been widely considered as an electrical power source in many
ground applications because of its clean and noiseless characteristics. Moreover, the hybrid photovoltaic
cell and TEG (PV/TEG) system has also received wide attention due to its improved power conversion
efficiency over its monolithic counterparts. This paper presents a study of the dynamics and the operation
of the hybrid PV/TEG system in an outer space environment where a unified thermodynamic model of
this system is presented. Moreover, the multi-objective NSGA-II genetic algorithm is utilized to optimize
the design of the TEG both in terms of optimal output power and in terms of mass. Specifically, the design
of the single stage and the two stage variant of the aforementioned TEG are considered. Simulation
results indicate that the optimized PV/TEG system does indeed achieve better efficiencies than that of
the monolithic counterparts. Furthermore, it is shown that the single stage TEG is more beneficial than
the two stage TEG in terms of achieving optimal performance.