Assessing hydrogen supply chains: An integrated review of leakage and energy efficiency studies

Abstract

This paper examines hydrogen leakage and efficiency across the supply chain for liquid, gaseous, and mixed hydrogen systems. These factors are crucial for assessing hydrogen's role in mitigating emissions and facilitating a clean energy transition. Drawing on a comprehensive review of existing literature and model-based analysis, the study compiles leakage rates and efficiency metrics at each stage of the supply chain: production, storage, transmission, distribution, and end-use. These data inform system scenarios that estimate the impact of leakage on overall performance and climate benefits. The analysis also identifies persistent data gaps, particularly for liquid and mixed system configurations, and outlines priorities for future research. A comparison of hydrogen system types shows that gaseous pathways generally achieve the highest efficiencies (28 %–39 %) and the lowest leakage rates (∼4.5 %) across the supply chain. Liquid hydrogen systems, while favorable for long-distance and high-volume transport due to their higher energy density, exhibit lower efficiency (∼28 %) and a greater leakage potential (∼12 %). Mixed systems, which combine gaseous and liquid elements (e.g., pipeline transmission followed by liquefaction and truck distribution), show compounded energy losses and moderate-to-high leakage rates (6.8 %–9.4 %), highlighting trade-offs associated with added system complexity. The study highlights opportunities for technological advancements, including optimizing liquefaction, enhancing insulation for storage and transportation, and refining refueling equipment. These improvements are crucial for maximizing the climate benefits of hydrogen. The results offer actionable insights for researchers, industry, and policymakers working to develop low-leakage, high-efficiency hydrogen infrastructure. • Study estimates H 2 leakage and efficiency across supply chains using literature-based scenarios for guidance. • Gaseous H 2 systems have ∼4.5 % leakage and up to 39 % efficiency; advantages grow over longer distances. • Liquid and mixed systems leak more (∼12 %, ∼9 %) and are less efficient (∼28 %, ∼25.2 %) but support high-density delivery. • Transmission and dispensing stages cause most leakage; liquefaction is the main efficiency bottleneck. • Leakage data rely on assumptions and proxies; real-world, standardized measurements are urgently needed.

Topics & Concepts