Steam electrolysis through solid oxide electrolysis cells (SOECs), are promising alternatives to steam reforming reaction for hydrogen generation in specific applications owing to its very high efficiency and clean products. However, the state-of-art SOEC relied on oxygen ion conductors (O-SOECs) that were required to be operated at high temperatures (>850^oC). Proton conducting SOECs (P-SOECs) are emerging technologies that used proton conductor as the electrolyte and can be run at reduced temperatures, overcoming those O-SOECs’ problems such as fast degradation, and hydrogen separation, etc. The challenges of P-SOEC is poor performance with sluggish electrode kinetics at reduced temperatures as well as unproven stability. In this work, we report our findings in design, fabrication, and characterization of an extremely highly efficient P-SOEC with a novel triple-conducting steam electrode below 600^oC in INL. The performance and durability of the P-SOECs exhibited significant improvement in comparison to those existing O-SOECs and P-SOECs.