CFAs: Development of Mined, Lined Rock Cavern for Gaseous Hydrogen Storage

Objectives

• Project results are expected to contribute to the following objectives (KPIs of the Clean Hydrogen JU SRIA are not applicable as such):
  • Undertake research activities on underground storage to validate the performance in different geologies, to identify better and more cost-effective materials and to encourage improved designs;
  • Support the development of Regulations Codes and Standards (RCS) for hydrogen technologies and applications, focusing on standards for assessing the life span of a mined, lined rock cavern for hydrogen storage;
  • Organise safety, Pre-Normative Research (PNR) and RCS workshops.

Funding Information

• Maximum amount: EUR 5.00 million.

Expected Outcomes

• Project results are expected to contribute to all the following expected outcomes:
  • Generate knowledge on the mechanical behaviour of a complex liner (concrete, steel, etc.) in combination with the geomechanical behaviour of the surrounding rock for a mined, lined rock cavern subject to cycling conditions and natural hazards (e.g., earthquakes);
  • Provide design principles and operation envelopes to be used by decision makers when assessing CAPEX and OPEX of mined, lined rock caverns in various conditions (rock mass quality, commercial needs, accessibility, security considerations, etc.);
  • Make hydrogen storage systems that are fit for purpose and that can reduce the cost and improve the efficiency of hydrogen supply across Europe available to industry;
  • Facilitate international collaborations to generate and apply knowledge that can improve underground hydrogen storage operations that contribute to hydrogen sustainability and reduce associated costs;
  • Contribute to maintaining European leadership for large-scale hydrogen storage solutions, with particular focus on assessing the opportunities to understand what makes a previously built cavern best suited for purpose, as well as to understand the dynamics of building mined, lined rock caverns in a diverse set of potential geological lithologies (e.g. gneiss, granite, carbonates, sandstones, basalts). Furthermore, identify and define which geological, geotechnical, and hydrological parameters are best suited for large-scale underground hydrogen storage;
  • Provide replication tools of the methodologies developed and demonstrated in the project in sites in other European regions with different subsurface (and operational) characteristics, ensuring an exhaustive coverage of the different European sites’ specifics;
  • Motivate technical and economic revitalisation of areas with abandoned and/or underutilised cavern infrastructure (e.g. tunnels, natural gas caverns, mines, etc.) in Europe.

Eligible Projects

• To overcome the gaps mentioned above, proposals should address the following:
  • Generate knowledge of steel behaviour when subject to cycling conditions in hydrogen environment under a range of operational demands. This may include simulations based on rupture mechanics, fracture propagation, plasticity theory, etc. This should also include validation by testing;
  • Generate knowledge on the corrosion of steel over time including the potential for crevice corrosion and pitting that could result in failure. Damage resulting from H2 embrittlement, or impurities within the H2 of the steel liner may also be considered. This includes knowledge generation on hydrogen quality after storage and withdrawal from the mined, lined rock cavern. This may include hydrogen analysis under simulated cavern conditions in the laboratory using material from the lined rock cavern in the test reactor or by testing gas samples from a field demonstration;
  • Generate knowledge on appropriate concrete compositions for cycle fatigue under a range of operational demands, as well as to best protect the integrity of both the steel liner and the surrounding rock mass. Alternative binders to Ordinary Portland Cement should be considered, to improve the environmental footprint while creating a concrete with higher durability. This may include simulations on fracture propagation, porosity/permeability analyses, as well as laboratory and/or field testing;
  • Design the concrete buffer slurry ensuring that it is designed to be space filling in such a way that it does not introduce stress/strain concentrations. It will likely require high pumpability, alongside good self-compacting properties with high gravitational stability. The use of expanding agents in the concrete mix may be considered through testing, to improve space filling properties and potentially pre-stress the steel liner;
  • Generate knowledge on how variations in geological conditions (e.g. lithology, depth, stress, temperature, etc.) impact both the short- and long-term performance of the storage site. This may include complex numerical simulations of the full storage system, taking into account fracture generation and propagation, fatigue, etc., as well as analogue modeling in the laboratory and/or field testing in a variety of representative geological conditions;
  • Develop recommendations for a standardised design for new mined, lined rock caverns, and best practices for converting existing caverns for hydrogen storage. This design should include underground and aboveground installations dedicated to the storage activity (hydrogen treatment, compression, piping, metering). Connecting lines between the cavern and the aboveground installations should also be covered. Additionally, it is important to consider the impact of natural hazards (e.g. earthquakes) on the entire system (e.g. steel liner, concrete, rock mass, etc.);
  • Understanding potential monitoring methods, including the storage site and surrounding rock mass, should be considered. Ideally, any field testing carried out would include various potential monitoring methods to understand advantages and disadvantages of each approach. Monitoring methods should be able to able to indicate potential failure, as well as other changes within the mined, lined rock cavern storage system (i.e. steel liner, concrete, rock mass, etc.);
  • Ascertain the design through a comprehensive set of simulations. A physical proof of concept (POC) should also be proposed. The parameters for the POC should be ascertained through a combination of numerical modelling, and laboratory testing. The proposal for a POC may be either or a combination of an above ground test that could be utilised to explore the impact of cycling hydrogen within a storage container on the various non-subsurface components (e.g., steel, concrete) and/or a series of tests designed to understand the impact of different geological conditions. Other POC approaches can be proposed provided they significantly improve the level of confidence in the concept.

For more information, visit European Commission.