Hydrogen Storage: Key Technology for the Energy Transition and Decarbonization
Hydrogen storage is essential for the energy transition. It enables the long-term storage of surplus energy from highly fluctuating renewable sources, such as wind power and photovoltaics, and makes it available when needed. Furthermore, hydrogen offers a promising alternative to fossil fuels and supports decarbonization. To ensure consumers transition to hydrogen in the long term, the demand-driven availability of H₂ is indispensable. This makes efficient and safe hydrogen storage a key technology and a vital link between production and consumption.
Hydrogen is the lightest element in the periodic table. It has a high gravimetric energy density of 33.33 kWh/kg but a very low volumetric energy density of only 2.8 kWh/m³ at normal pressure. These properties necessitate innovative storage solutions.
Technologies for Hydrogen Storage
High-Pressure Storage (Compressed Gaseous Hydrogen, CGH₂)
In high-pressure storage, hydrogen is stored in specialized tanks at pressures of up to 700 bar. This method is widely used, especially in mobility applications.
Liquid Hydrogen Storage (LH₂)
In this method, hydrogen is liquefied by cooling it to -253°C. This increases the volumetric energy density but is highly energy-intensive.
Physically Bound Storage
Hydrogen is stored in solid materials such as metal hydrides. This technology allows for safe storage but is not yet widely available.
Chemically Bound Storage
Hydrogen is stored in chemical compounds such as ammonia or methanol. This method offers high storage density and facilitates easy transportation.
Cavern Storage
Cavern storage utilizes underground cavities to store energy in the form of hydrogen. These caverns are either created in natural salt formations or in depleted natural gas fields. By using modern technologies, large amounts of energy can be stored safely and efficiently, making cavern storage a key technology for the future.
Expertise in Hydrogen Storage
The market offers a wide range of hydrogen storage solutions, distinguished by varying pressure levels and material compositions. Key challenges include seasonal storage, the sustainability of storage technologies, and efficient integration into the overall system. The pressure differences between electrolyzers (1–10 bar) and end-use applications (100–700 bar) must be addressed with suitable compression methods. System design requires careful coordination of all components, such as renewable energy sources, electrolysis technology, compressors, storage systems, and their capacities and pressures, to ensure continuous supply. Additionally, investment and operating costs play a crucial role in determining the price of hydrogen.
AIT supports companies and institutions in implementing hydrogen storage projects through:
- Technical feasibility studies.
- Economic and risk analyses, as well as market forecasts.
- System design, optimization, and operational concepts.
- Assistance with planning and implementation of H₂ storage projects.
- Analysis of regulatory frameworks.