I worked for 30 years in the process control industry, selling control systems to oil & gas, electricity generation, chemicals, water treatment etc. The one thing new plant commissioning engineers ran a mile from was a new hydrogen plant.
The fundamental problem with hydrogen is that it is the smallest molecule in the periodic table. This means it is difficult to contain it within storage systems made of elements with larger molecules. Given this propensity for leakage, and the fact that it has a low energy density compared with other fuels like gasoline or LPG (so it needs to be stored at high pressure to make it economically viable), means there are fundamental problems with its manufacture, transportation and storage.
ChatGPT says it better than I can:
What are the problems with storing hydrogen?
Storing hydrogen presents several challenges due to its unique properties:
- Low Energy Density: Hydrogen has a very low energy density by volume compared to traditional fuels like gasoline or natural gas. This means large volumes of hydrogen are needed to store significant amounts of energy.
- Storage Methods: There are several methods for storing hydrogen, each with its own challenges:
- High-pressure Tanks: Hydrogen can be stored in high-pressure tanks, typically at pressures of 350-700 bar. However, this requires strong and lightweight materials to withstand the pressure, which can be costly and challenging to manufacture.
- Cryogenic Storage: Hydrogen can be stored as a liquid at very low temperatures (below -253°C). This requires energy-intensive refrigeration and specialized tanks to maintain the low temperatures, which adds to the cost and complexity.
- Solid-state Storage: Storing hydrogen within materials like metal hydrides or carbon-based materials is another approach. However, achieving sufficient storage capacity and release rates remains a challenge.
- Safety: Hydrogen is highly flammable and can form explosive mixtures with air over a wide range of concentrations (4-75% hydrogen by volume). Ensuring safe storage requires rigorous safety measures, such as proper ventilation, leak detection systems, and explosion-proof infrastructure.
- Material Compatibility: Hydrogen can cause embrittlement in metals, potentially leading to mechanical failures over time. This requires materials that are resistant to hydrogen embrittlement or the use of protective coatings.
- Leakage: Hydrogen molecules are very small, which can lead to leakage through seals and fittings that might not be an issue with larger molecules. Minimizing leakage rates is crucial to prevent loss and ensure safety.
- Infrastructure Compatibility: Existing infrastructure, such as pipelines and storage facilities, is primarily designed for natural gas and might not be suitable for hydrogen without modifications. Retrofitting or building new infrastructure adds to the cost and complexity of hydrogen storage.
Addressing these challenges requires advances in materials science, engineering solutions for safe handling and storage, and infrastructure development tailored to hydrogen-specific needs.