BACKGROUND

· Efficient, large-scale and safe hydrogen storage is a key factor for successfully establishing a hydrogen economy.

· Hydrogen has a higher energy potential per unit mass than any other type of fuel. However, as it is a gas with a very low density, the amount of energy that can be stored per unit volume is very small.

· Underground hydrogen storage technology has not yet been sufficiently developed to meet the low cost, high energy density, durability and safety criteria.

HYDROGEN STORAGE METHODS

depending on its physical properties and the type of technology:

· As liquid hydrogen (LH2) or cryo-compressed gaseous hydrogen (CCGH2)

· In liquid organic hydrogen carriers (LOHC)

· In porous materials (MOFs or carbon nanostructures)

· In the form of ammonia (NH3) or methanol (CH3OH)

· In metal hydrides

· As compressed gas (CGH2). Most common and technologically mature storage method.

ᵒ On a small scale: at high pressure in tanks or bottles made of different materials. To date, four types of tanks have been developed according to their manufacturing architecture: Type I, II, III, IV, Type V (still under development).

ᵒ On a large-scale: it can be stored as compressed gas in stationary systems, such as salt caverns, old aquifers, lined rock caverns and natural gas fields. These systems have a major advantage in that they both reuse existing geological structures and create new cavities, both of which are able to confine large quantities of hydrogen at moderate pressures at a low cost.

· The European Hydrogen Corridor project in Spain to connect the peninsula with Europe considers the construction of a large hydrogen storage facility in the Basque Country.

· Locations are currently being studied in the many salt cavities in the Cantabrian-Basque basin, one of the areas of the peninsula with the best geological formations for this purpose.

Slightly porous rock structures

“Optimum quality” conditions

Possible-hydrogen-storage-facilities-H2Salt-EN

H2SALT seeks to develop a system for the integrated management of salt cavern hydrogen storage and validate its technical and economic viability.

Underground hydrogen storage technology is currently underdeveloped at a national and European level, and there are very few facilities providing this type of storage.

Lack of knowledge and experience in:

Properties of subsoil and salt rocks.

Permeability and reactivity of hydrogen with salts, rocks and materials used in salt caverns.

Hydrogen leaks from pipes, valves, joints, seals, etc

Requirements and specifications of the tubular salt cavern injection and extraction systems and auxiliary systems for its operation.

Therefore, the possibility of proposing business models that involve both the use of salt caverns and the generation of new cavities as storage for large industrial facilities that use hydrogen as a raw material (fertilisers, steel, etc.) is non-existent.

H2SALT shall have the appropriate test methodologies to assess embrittlement and cracking caused by hydrogen. It will also carry out an exhaustive study of the existing boreholes and tests in order to characterize the salt formations in the area and thus model the cavern so as to study the feasibility of hydrogen storage in national salt formations

This project has received funding from “Recovery, Transformation and Resilience Plan – Funded by the European Union – NextGenerationEU