Green Hydrogen: Production Technologies, Challenges, and Role in Sustainable Energy Systems

Abstract

The increasing environmental impact of fossil fuel consumption has accelerated interest in sustainable energy carriers, with green hydrogen emerging as a key option for decarbonization. This review critically evaluates the current status of green hydrogen production technologies, including alkaline water electrolysis (AEL), proton exchange membrane electrolysis (PEMEL), anion exchange membrane electrolysis (AEMEL), and solid oxide electrolysis cells (SOECs). Reported system efficiencies range from approximately 60–70% for conventional alkaline systems to over 80% for advanced SOEC technologies under optimized conditions. Recent advances in electrocatalysts, membrane materials, and renewable energy integration have improved system performance; however, challenges related to capital cost, durability, scalability, hydrogen storage, and transportation remain significant barriers to large-scale deployment. The review further highlights emerging research directions, including hybrid electrolysis systems, artificial intelligence-assisted optimization, and advanced catalyst development. Overall, green hydrogen demonstrates strong potential to support deep decarbonization and long-term energy storage, although continued technological innovation and cost reduction are required for widespread commercialization