Green hydrogen production pathways: Comparative insights from Denmark, the United States, and China

In the pursuit of reducing carbon emissions in hard-to-decarbonize sectors such as heavy industry and shipping, power-to-hydrogen technology offers a promising pathway. The technology uses water electrolysis to convert renewable energy into hydrogen, which can then be used directly as hydrogen fuel with a fuel cell to produce electricity for transportation or grid balancing or used for steel, ammonia, and methanol production. This study evaluates and compares power-to-hydrogen systems by examining system scale, geographical conditions, design choices, configuration, operational strategies, and other key factors critical in shaping system performance. Efficiency and cost are assessed as separate but related aspects influencing the overall viability of green electrolyzer systems (electrolyzers powered by clean, renewable electricity). The analysis of power-to-hydrogen systems in Denmark, the United States, and China reveals variations in costs, technological approaches, and strategic implementations across these regions. The comparative evaluation shows that the economic viability of these systems is largely driven by design choices and operational strategies. The findings highlight that customizing power-to-hydrogen systems to local conditions is essential for achieving optimal cost-effectiveness.