A cross-regional analysis of policies, regulations, and incentives from the United States, the European Union, China, and Australia for shaping hydrogen economy

Global efforts to achieve net-zero emissions have accelerated interest in hydrogen as a clean energy vector. However, national and regional policy frameworks differ widely in scope, maturity, and implementation. This study presents a comparative evaluation of hydrogen policies in the European Union (EU), United States (US), China, and Australia using a hybrid PESTLE–TOPSIS (Political, Economic, Social, Technological, Legal, and Environmental) approach. The framework integrates qualitative policy analysis with quantitative multi-criteria to ensure a transparent and reproducible measure of policy effectiveness. The analysis reveals that the EU achieved the highest composite score (0.872), reflecting its well-structured regulatory system and cohesive hydrogen strategy. The USA (0.738) ranks second, supported by strong R&D investment and incentives but constrained by policy volatility. Australia (0.614) demonstrates substantial progress through export-oriented initiatives, while China (0.493) trails due to fragmented governance and higher carbon intensity in production. These scores represent the final normalized PESTLE–TOPSIS results validated through sensitivity analysis to ensure methodological rigor and consistency across the study. The findings highlight that policy effectiveness depends on the integration of technological, economic, and legal stability rather than any single policy dimension. This study provides one of the first systematic cross-regional evaluations of hydrogen policy maturity, offering actionable insights for policy harmonization, investment prioritization, and global coordination toward a sustainable hydrogen economy.