The future of hydrogen as a strategic enabler in integrated energy systems: Technological developments, barriers, and policy implications

Hydrogen presents a unique opportunity to transform Integrated Energy Systems (IES) by enhancing efficiency, flexibility, and sustainability across electricity, heat, and transport sectors. This comprehensive review examines hydrogen’s complete supply chain — production, storage, and transportation — as a strategic backbone for IES, departing from traditional perspectives that examine these components in isolation. The paper synthesizes recent advancements in hydrogen production (e.g., green electrolysis, blue SMR), storage (e.g., gaseous, liquid, and solid-state methods), and transportation (e.g., pipelines and chemical carriers), emphasizing their integration within IES. Additionally, the review assesses emerging technologies, such as increasingly cost-competitive green hydrogen and advanced storage materials, while identifying key research gaps and challenges related to scalability and economic viability. Notably, the cost of green hydrogen has decreased to USD 3.7–11.7 per kg (average ∼ USD 4.5–6/kg in Europe), with projections indicating a further reduction driven by declining renewable energy costs and electrolyzer advancements. The study analyzes recent literature and systematically summarizes key findings into comparative tables to offer a structured overview, facilitating a clear understanding of technological advancements and research trends. Furthermore, real-world hydrogen projects are discussed within each section, demonstrating practical implementations and existing challenges in the field. This paper synthesizes cutting-edge developments, real-world applications, and critical gaps — including cost reduction, material scalability, and system optimization — proposing research directions and policy strategies to overcome barriers. it frames hydrogen as a strategic enabler of decarbonization, aligning with SDG 7. This work proposes a roadmap for researchers, engineers, and policymakers, highlighting policy incentives, research priorities, and quantitative insights to shape energy strategies. • Comprehensive Analysis of Hydrogen’s Strategic Role in Integrated Energy Systems. • Evaluation of Recent Technological Advancements. • Quantitative Insights into Cost and Efficiency Trends. • Systematic Assessment of Challenges and Research Gaps. • Real-world applications and Policy Implications.