Аннотация
Transition toward a low-carbon economy has positioned green hydrogen as a key vector for sustainable energy systems. Large-scale deployment remains constrained by transportation and storage challenges, particularly across complex inland water bodies such as the Caspian Sea. This study presents a comprehensive overview of existing strategies and emerging innovations for transporting green hydrogen across the Caspian Sea, with emphasis on geomorphological and hydrological constraints. The Caspian Sea, the world’s largest enclosed inland water body, spans approximately 371000 km 2 with an average depth of 211 m, and features extensive shallow zones along its northern and eastern coasts. These physical characteristics, combined with variable salinity, seasonal currents (averaging 5 to 25 cm s -1 ), and sediment transport, complicate the establishment of reliable and secure transport routes. Influence of these geographical factors on marine infrastructure planning, pipeline installation, and shipping routes were analysed in this study. The present review explores innovative maritime hydrogen transport technologies, including cryogenic liquid hydrogen tankers and ammonia-based carriers, while assessing their feasibility in high-sediment zones. The study also evaluates optimal storage methods, such as compressed hydrogen, metal hydrides, and liquid organic hydrogen carrier systems, against criteria of safety, cost efficiency, and environmental resilience. Geospatial analyses and comparative route modelling highlight critical corridors that minimize exposure to geomorphological hazards, enabling reductions in energy loss and logistical risk. Optimization approaches may also lower hydrogen losses during transport (with indicative estimates of up to ∼18%) and reduce infrastructure costs by 12 – 20% relative to conventional routing strategies. This study also identifies gaps, provides future research perspectives and policy development supporting trans-Caspian green hydrogen infrastructure. Findings from this study are of strategic importance for regional energy cooperation, particularly among Central Asian and Caucasus states aiming to establish themselves as hydrogen exporters to Europe. • Caspian Sea geomorphology and hydrology constrain hydrogen transport routes • Maritime transport and storage options assessed for safety and cost efficiency • Geospatial modelling optimized routes, cutting loss by 18% and costs by 12–20% • Policy insights support trans-Caspian hydrogen infrastructure and cooperation