The technical and socio-economic possibilities of massive hydrogen (H₂) storage in porous media were explored at the hystories conference in Paris, France on May 25 and 26. The HYSTORIES (HYdrogen STORage In European Subsurface) project is funded by the European Union and led by Geostock. The conference displayed the results of 2 1/2 yr of research within the project.

Day 2 of the conference kicked off with Dr. Pascal Baylocq from Geostock providing the benefits of underground H₂ storage. According to Baylocq, storing H₂ underground enables the storage of 4,000 t (tons) of H₂ as opposed to storage in a cryogenic system, which can only store a few hundred t of H₂. It is also much more cost-effective to store H₂ underground.

"Let's say you invest a CAPEX of €500 MM; underground, you can store between 250 t–500 t of H₂," Baylocq said. "If you go into a lined rock cavern, you will be able to store 600 t–1,200 t, but if you go into a salt cavern, you will be able to store up to 17,000 t of H₂."

Baylocq went on to describe the amount of storage capacity required depending on the H₂ production quantity in France (6 GW), Europe (40 GW) and worldwide (90 GW), as predicted by 2030. If 5% of this production is to be stored, France will need approximately an additional 20–40 salt caverns, Europe will need between 120–250 salt caverns and 200–400 salt caverns will be required worldwide.

The second presenter was Christopher Kutz, project manager at Ludwig-Bölkow-Systemtechnik GmbH (LBST), and he discussed the role of underground H₂ storage in the European energy system. They first needed to determine the demand for H₂ storage to understand the future European energy system, while considering each unique countries.

They used the LBST ENergy System (LENS) model to assess 2030, 2040 and 2050 scenarios. The primary H₂ storage-related parameters used were:

• The total storage volume capacity
• The maximum injection and withdrawal capacity
• The number of total cycle equivalents
• The impact of H₂ flows and infrastructure requirements.

They modeled the power grid with renewable and dispatchable power plants, various storage technologies, and demand-side management. In addition, the whole H₂ grid with the electrolyzers and the H₂ turbine as key sector coupling technologies.

They focused on the different storage technologies, such as salt caverns, storage in depleted oil fields and saline aquifers, but they did not look much into the line rock storage technique. The three main end-use sectors examined were industries, mobility and residential.

"In the first step, we took the long-term investment decisions and different capacities," Kutz said. "The second step was scheduling—when each power plant should produce, and the third step was to reexamine the grid and see where additional capacity was needed between the countries. With this model, we have discovered the economic optimization of the best, most cost-minimal solution for the whole European energy system."

The documentation with all the results is available on the Hystories website.

Story by: Tyler Campbell, Managing Editor, H2Tech