Greenhouse Gas Reduction Potential and Economics of Green Hydrogen via Water Electrolysis: A Systematic Review of Value-Chain-Wide Decarbonization

Green hydrogen generated via water electrolysis has become an essential energy carrier for achieving carbon neutrality globally because of its versatility in renewable energy consumption and decarbonization applications in hard-to-abate sectors; however, there is a lack of systematic analyses of its abatement potential and economics as an alternative to traditional technological decarbonization pathways. Based on bibliometric analysis and systematic evaluation methods, this study characterizes and analyzes the literature on the Web of Science from 1996 to 2023, identifying research hotspots, methodological models, and research trends in green hydrogen for mitigating climate change across total value chain systems. Our review shows that this research theme has entered a rapid development phase since 2016, with developed countries possessing more scientific results and closer partnerships. Difficult-to-abate sectoral applications and cleaner production are the most famous value chain links, and research hotspots focus on three major influencing factors: the environment; techno-economics; and energy. Green hydrogen applications, which include carbon avoidance and embedding to realize carbon recycling, have considerable carbon reduction potential; however, uncertainty limits the influence of carbon reduction cost assessment indicators based on financial analysis methods for policy guidance. The abatement costs in the decarbonization sector vary widely across value chains, electricity sources, baseline scenarios, technology mixes, and time scenarios. This review shows that thematic research trends are focused on improving and optimizing solutions to uncertainties, as well as studying multisectoral synergies and the application of abatement assessment metrics.