Hydrogen storage technologies for future energy systems

Hydrogen is a shining clean energy vector in the journey toward net-zero, possessing a gravimetric energy density of 120 MJ/kg and potential to decarbonize transport, industry, and power sectors. Its rollout necessitates, however, the development of efficient and scaled-up storage technology. This chapter provides an in-depth technical description of hydrogen storage technologies including compressed gas (350–700 bar), liquid hydrogen (−253 °C), metal hydrides (1.5–2.0 wt% H₂ capacity), chemical carriers, and advanced solid-state porous materials such as MOFs (>3000 m²/g surface area). Each system is examined in terms of its energy density, cycling stability, thermodynamic behavior, and integration feasibility. Thermal and mass transfer modeling proves that inefficient heat dissipation lowers hydrogen uptake by 30–40% for hydride systems. Round-trip efficiencies of compressed and liquefied storage systems range from 30% to 45%, and energy losses are 5–15 kWh/kg H₂. Blending hydrogen with renewable power sources such as solar pressure vessel and wind decreases curtailment by over 25% and enhances energy autonomy in hybrid microgrids to 90% or higher. Levelized cost of storage (LCOS) varies greatly, from <$1/kg H₂ for salt caverns to >$1,500/kg H₂ for metal hydrides. Lifecycle assessments (LCA) indicate that green hydrogen storage systems have the potential to emit <2 kg CO₂e/kg H₂, assuming supply by renewables, compared to 10–14 kg CO₂e/kg H₂ for conventional systems. This chapter provides a comparative synthesis of technical, economic, and environmental performance, setting the foundation for future investigations and deployment of hydrogen storage into sustainable energy systems.