Abstract A novel hybrid solar energy conversion system, integrating a solar-driven thermionic energy converter (STEC) and an inhomogeneous thermoelectric generator (ITEG), is proposed to evaluate its performance through theoretical modeling and parametric study. Filling the gap in hybrid thermal-electric systems, this study innovates with a hierarchical STEC-ITEG design and optimization framework. The STEC subsystem utilizes an optical concentrator to convert solar radiation into electricity via thermionic emission, while the residual heat is harnessed by the ITEG for secondary energy conversion. The model is validated via MATLAB simulations, achieving a peak efficiency of 33. 22 %, surpassing typical crystalline silicon solar cells (∼25 %), with the ITEG efficiency reaching 12. 26 % at an optimal spatial inhomogeneity coefficient (d IT = 0. 5 d₈ₓ=0. 5). Parametric studies highlight the critical role of variables such as electrode gap, anode temperature, thermocouple quantity, spatial inhomogeneity coefficient, and geometric characteristics in enhancing performance. Optimal electrode gap design mitigates space-charge effects and radiative losses, while reduced anode temperature minimizes reverse radiation. For the ITEG, tailored geometric and spatial designs enhance temperature gradient distribution and conversion efficiency, though reduced gains occur beyond certain thresholds. The complementary functions of STEC and ITEG ensure efficient utilization across thermal gradients. However, practical implementation faces challenges in material stability, thermal coupling, and economic trade-offs.
Zhang et al. (Thu,) studied this question.