The future of hydrogen: Challenges on production, storage and applications

With the demand for hydrogen being expected to increase by about 8-folds in 2050 over 2020, there are several factors that can turn into challenges for effective roll out of hydrogen applications in energy sector. Hydrogen has the second highest calorific value, 120-142 MJ/kg, which is the best energy-weight ratio among all conventional fuels. Among all hydrogen production processes, the green hydrogen production through mature water electrolysis process, with technology readiness level of ∼7-8 (demonstration/system development) and commercial readiness index of ∼ 4-5 (deployment) contributed about 30% to market share with efficiency of 55-80% and production cost of ∼ $4-7/kg H2. This study found that the current hydrogen production costs may reduce to desired 1-2 $/kg H2 within a couple of decades, but there is still a lack of plans for combining various hydrogen production processes where necessary, rather than only focusing on producing hydrogen in mass scale. Among all the hydrogen storage systems, the specific volumetric storage cost of metal hydride is less, about $125/m3, than other systems. Ammonia has lowest specific energy cost, about $13/GJ amongst other storage systems. There is a requirement of rapid progression in relevant infrastructure development for efficient supply chain management for storage, transportation, and delivery of hydrogen to the stakeholders. This paper reviewed 400+ articles and summarised hydrogen production processes, storage options, production costs and applications. The synthesis of key information and deep analysis of limitations of existing studies has been provided followed by deep discussion on the challenges of hydrogen as energy carrier for future. To achieve sustainable development goals, integrated plans, infrastructure development, reduction of production costs, achieving net zero emissions and novel storage development need to be achieved within 2050. This reviews thus could be used as a guideline by policymakers, researchers, and scientists for shaping future of hydrogen.