Current Options and Future Trends in Green Fuels Storage

The global transition to renewable energy underscores the urgent need for safe, efficient, and cost-effective storage solutions for green hydrogen and green ammonia. This review critically examines their fundamental characteristics and unique behaviours, emphasising storage, handling, and integration engineering challenges. To identify the influential studies, knowledge gaps and future trends in the research area, a systematic Scopus-based bibliometric and data analysis is conducted. A novel approach is adopted to identify the better green energy storage option between green hydrogen storage and green ammonia storage, combining a risk-mitigation assessment framework, strengths, weaknesses, opportunities, threats (SWOT) analysis, and a multicriteria taxonomy based on the properties and behaviour of hydrogen and ammonia. This study also analysed and reviewed the performance of the hydrogen and ammonia storage system across technical, thermomechanical, safety/risk and economic dimensions. This review further addresses the limitations in technological bottlenecks, unresolved safety concerns and current simulation approaches to evaluate the performance of green hydrogen and green ammonia. The identified limitations open doors to future research priorities in this research area, including the techno-economic viability, standardisation, and modelling accuracy of hydrogen and ammonia storage systems. The evaluation presented by this study allows for precise identification of suitable energy storage based upon various operational and economic contexts.