Green Hydrogen Production Using Low-Cost Alkaline Electrolysis Powered by Renewable Energy

Abstract

Abstract Hydrogen has gained significant attention as a clean energy carrier capable of supporting industrial decarbonization and the integration of renewable energy sources. This study experimentally investigated hydrogen production through alkaline water electrolysis using potassium hydroxide (KOH) as the electrolyte and stainless-steel electrodes in a laboratory-scale system powered by a regulated direct-current source simulating renewable electricity. The effects of electrolyte concentration (100–600 g/L KOH) and applied voltage (5–12 V) on hydrogen generation were evaluated over a fixed period of 60 minutes, with gas volumes determined indirectly through gravimetric mass-loss measurements and reported at standard temperature and pressure (STP) conditions. The results showed that hydrogen generation was strongly influenced by electrolyte concentration, with no measurable production observed at 100 g/L and 200 g/L due to insufficient ionic conductivity. Hydrogen evolution initiated at 400 g/L and increased substantially at 600 g/L, achieving a maximum calculated hydrogen volume of 2.5879 L and a peak Faradaic efficiency of 61.89% at 12 V. Increasing the applied voltage generally improved hydrogen yield, though a severe performance collapse down to a 1.62% efficiency occurred at 400 g/L and 12 V due to Ohmic Joule heating and electrode shielding via the gas-curtain effect. Furthermore, the stainless-steel electrodes exhibited excellent electrochemical stability with no macroscopically observable wear, confirming their viability as a durable, low-cost catalyst alternative. Overall, the findings demonstrate that efficient hydrogen production can be achieved using an optimized, low-cost gravimetric system, highlighting its potential for decentralized applications.