Gasunie, a gas infrastructure company, has announced that it will join H2CAST, a hydrogen storage pilot project in the Etzel caverns of Lower Saxony, Germany. The project, which is a partnership between Gasunie and STORAG ETZEL, aims to develop large-scale hydrogen storage in salt caverns near Etzel. The pilot project will involve making two existing caverns suitable for hydrogen storage and connecting them with an above-ground facility. Gasunie will be responsible for the above-ground facility. The pilot project is expected to be completed in 2026 and is strategically located near the Dutch and German hydrogen market and the Gasunie hydrogen network HyPerLink. The project is co-funded by the state of Lower Saxony and the Federal Government of Germany.
What are salt caverns and how it can be used to store hydrogen?
Salt caverns are natural underground structures that are formed by the dissolution of salt deposits. They can be created by dissolving salt layers through the injection of water, which creates a large underground cavity. These caverns are typically found in salt mines and can reach depths of several thousand feet.
Salt caverns can be used to store hydrogen because of their unique physical properties. The caverns are typically made of rock salt, which is a dense and stable material that can withstand the high pressures and temperatures associated with hydrogen storage. Additionally, the caverns are typically located deep underground, which provides a natural barrier that can help to contain the hydrogen and prevent leaks.
There are two main methods for storing hydrogen in salt caverns. The first is called pressurized storage, in which hydrogen is stored at high pressures to increase its density. The second method is called liquefied storage, in which hydrogen is cooled to very low temperatures to turn it into a liquid, which also increases its density. Both methods allow for large quantities of hydrogen to be stored in relatively small spaces.
In the H2CAST project, the hydrogen is stored in pressurized form. The caverns will be made suitable for hydrogen storage by injecting water and dissolving the salt to create large underground caverns, and then the caverns will be connected by an above-ground facility and will be ready for hydrogen storage in 2026.
Pros and Cons of storing hydrogen in salt caverns
The benefits of storing hydrogen in salt caverns include:
- High storage capacity: Salt caverns can store large quantities of hydrogen, making them suitable for large-scale hydrogen storage projects.
- Safe and secure: Salt caverns are located deep underground, which provides a natural barrier that can help to contain the hydrogen and prevent leaks. Additionally, rock salt is a dense and stable material that can withstand the high pressures and temperatures associated with hydrogen storage.
- Cost-effective: Salt caverns are relatively inexpensive to create and maintain, making them a cost-effective option for hydrogen storage.
- Location: Salt caverns are often found near existing hydrogen production and distribution infrastructure, making them well-suited for hydrogen storage projects.
However, there are also some potential drawbacks to storing hydrogen in salt caverns:
- Complexity: Creating and maintaining salt caverns can be a complex and time-consuming process, which may increase the overall cost of the project.
- Limited availability: Salt caverns are not found in every location, which may limit the potential for hydrogen storage projects.
- Safety concerns: The process of creating and maintaining salt caverns can be dangerous, and hydrogen storage in salt caverns has to follow strict safety guidelines.
- Environmental concerns: The process of creating salt caverns can have environmental impacts, such as changes to groundwater levels and potential damage to nearby ecosystems.
Overall, while storing hydrogen in salt caverns has several advantages, it also has some drawbacks that need to be considered before deciding to use it as a storage method.