A Four-Dimensional Governance Framework for Hydrogen Energy Policy: A Comparative Institutional Analysis of G20 Nations

Hydrogen energy has emerged as a strategic pathway for decarbonization, industrial transformation, and energy security across major economies. This study does not directly evaluate ex post policy outcomes. Instead, it develops a Four-Dimensional Governance Framework to assess the structural effectiveness and implementation-oriented capacity embedded within national hydrogen policy frameworks. The analysis examines G20 countries through four dimensions, namely policy objectives, policy intensity, policy tools, and policy subjects. Using the entropy weighted TOPSIS method, the study compares the relative coherence of hydrogen governance architectures across countries. The results show that countries such as the United States, the United Kingdom, Germany, France, Canada and Japan consistently rank among the leading group in the comparative evaluation, while other countries occupy intermediate or lower positions according to the composite index results. Policy subjects and policy objectives receive relatively higher weights in the empirical analysis, indicating their stronger contribution to cross-national differentiation within the constructed index. The study provides a structured basis for comparing hydrogen governance frameworks and offers a replicable method for future research linking policy design to implementation evidence.