Geometrical Optimization and Thermal‐Stability Characterization of Te‐Free Thermoelectric Modules Based on MgAgSb/Mg3(Bi,Sb)2

modules. Furthermore, module robustness against > 10 160 thermal cycles while preserving a relative efficiency of 95% is demonstrated. These findings highlight the importance of the optimization strategy at the module level and demonstrate the feasibility of using Te-free thermoelectric compounds to harvest the omnipresent low-grade heat.