Green Hydrogen

Abstract

Green hydrogen has emerged as a pivotal energy vector in the global pursuit of decarbonization, energy security, and climate resilience. Produced through electrolysis powered by renewable sources such as wind, solar, or hydro, green hydrogen offers a clean, scalable alternative to fossil fuels for sectors that are hard to abate—including heavy industry, shipping, aviation, and grid storage. This review presents a comprehensive analysis of global efforts in green hydrogen production, deployment strategies, policy support, and technological innovation. The paper evaluates country-specific roadmaps, electrolyzer technologies, cost trajectories, infrastructure challenges, and integration with renewable power systems. A comparative analysis of leading regions—such as the European Union, Gulf countries, Australia, China, and North America—illustrates different strategic pathways and progress levels. The study also highlights critical bottlenecks including water availability, electrolyzer efficiency, hydrogen transport and storage, and the lack of harmonized standards. Based on a synthesis of over 70 high-impact publications and project databases, this review outlines the techno-economic potential of green hydrogen and its role in future energy systems. Key findings indicate that while the levelized cost of hydrogen (LCOH) remains above $4/kg in most regions, rapid deployment and innovation are expected to reduce this to below $2/kg by 2030. The paper concludes by recommending pathways for international collaboration, investment frameworks, and research priorities to accelerate the green hydrogen transition.