Storing Renewable Energy in the Hydrogen Cycle

Area of Science:

• Energy science
• Materials science
• Chemical engineering

Background:

• Renewable energy systems require substantial energy storage, approximately 50% of annual consumption.
• Hydrogen is a key synthetic energy carrier for a sustainable energy economy.
• The hydrogen cycle involves production, storage, and utilization, forming a closed-loop system.

Purpose of the Study:

• To address the challenge of scaling up electrolyzer technology for large-scale, high-purity hydrogen production.
• To investigate safe and efficient large-scale hydrogen storage solutions.
• To explore advanced materials for hydrogen storage, exceeding the density of liquid hydrogen.

Main Methods:

• Focus on electrolysis technology for hydrogen production, particularly scaling to multi-megawatt power ranges.
• Investigate molecular and atomic hydrogen storage methods, including hydrides.
• Conduct research on novel storage materials, combining complex hydrides with amides.
• Study hydrogen sorption mechanisms for improved reaction control.

Main Results:

• Electrolysis is a mature technology up to 100 kW, but scaling to MW range presents challenges in efficiency and purity.
• Molecular hydrogen storage is limited by liquid hydrogen density.
• Complex hydrides offer higher hydrogen density (20 mass%, 150 kg/m³), double that of liquid hydrogen.

Conclusions:

• Advancing electrolyzer technology is crucial for large-scale hydrogen production.
• Developing advanced hydrogen storage materials is essential for a viable hydrogen economy.
• Further research into complex hydride-amide combinations and sorption mechanisms will optimize hydrogen storage applications.