COMPREHENSIVE STUDY OF ELECTROLYTE TYPE, ELECTRODE MATERIAL, AND SYSTEM EFFICIENCY IN SOLAR-POWERED ALKALINE WATER ELECTROLYSIS FOR HYDROGEN PRODUCTION

This paper presents the combined results of three interrelated studies: (1) the effect of electrolyte type — KOH, NaOH, and K₂CO₃ — on hydrogen production in an alkaline electrolyzer; (2) the effect of electrode material — 316L stainless steel, pure Ni, Ni-Mo alloy, NiFe oxide, and Ni-Mo/NiFe composite — on electrochemical efficiency; and (3) an overall system efficiency analysis of a photovoltaic (PV) array integrated with an alkaline electrolyzer via an MPPT controller. Experimental results show that 30% KOH provides the highest ionic conductivity (620 mS/cm), while the Ni-Mo/NiFe composite electrode achieves the lowest overpotential. Combined with an MPPT controller, a 5 kW PV system can produce 160–180 kg of green hydrogen per year under Andijan, Uzbekistan climatic conditions.