Comprehensive Analysis of Green Hydrogen Production: Technologies, Costs, Environmental Impacts, and Policy Frameworks

Abstract: Green hydrogen, produced via electrolysis using renewable energy, is a critical pathway to decarbonizing energy systems. This study compares key electrolysis technologies, including Alkaline (AE), Proton Exchange Membrane (PEM), Solid Oxide (SOE), and Anion Exchange Membrane (AEM) systems. SOE demonstrates the highest efficiency ranging from 80% to 90% which operates at elevated temperatures ranging from 700°C to 900°C, and has higher capital costs per Kilowatt which ranged from $2,000 to $3,000 per kW. PEM offers rapid response times ranging from 10 s to 30s and high hydrogen purity of 99.99% but suffers from shorter lifespans ranging from 40,000 to 60,000 hours. Material advancements, such as Nafion™ membranes and Iridium Oxide catalysts, enhance efficiency by up to 10%. Hydrogen storage methods reveal compressed hydrogen as suitable for short-term applications, while ammonia carriers and LOHC excel in long-term storage due to their safety and cost efficiency. Distribution technologies vary, with pipelines having cost-effective of $0.05/kg H₂/km over long distances, while trucks offer flexibility for shorter ranges. Environmental analysis highlights the carbon intensity disparity, with green hydrogen emitting 0 to 0.5 kg CO₂/kg H₂ compared to grey hydrogen’s which emits 10 to 12 kg CO₂/kg H₂. Lifecycle water consumption ranges from 7 to 12 L/kg H₂, with SOE being the most water-efficient. Global hydrogen projects, such as Saudi Arabia's NEOM with 650,000 tons per year and Europe’s HyDeal Ambition with 1,500,000 tons per year, illustrate the large-scale adoption of hydrogen technologies. Policy frameworks, including the EU Hydrogen Strategy and the USA Clean Hydrogen Plan, emphasize subsidies and infrastructure investments. This comprehensive analysis underscores the potential of green hydrogen, provided technological, environmental, and policy challenges are addressed effectively.