Hydrogen Geological Storage Fire and Explosion

Joint Industry Project

Challenge

Storing hydrogen in salt caverns and porous rock storage can play an important role in helping deliver the energy transition while meeting the targets of the Paris Agreement. Hydrogen storage at scale will be used for various purposes such as energy security, decarbonizing industrial processes, balancing supply and demand, and maximizing recovery of variable electricity from wind and solar. There are four commercial hydrogen salt caverns and several pilot projects in operation globally. As the energy transition accelerates, the number of geological storage storing hydrogen is expected to increase significantly. The underlying question is whether existing standards for natural gas salt cavern and porous rock storage can be applied to hydrogen from a safety/major hazard perspective and, if not, how they need to be changed. The storage of hydrogen in geological storage requires good design, based around safety. DNV has contacted nearly 50 companies and gathered extensive feedback on the top industry challenges. Following studies by the Dutch Ministry of Economic Affairs and Climate (KEM-28), German Federal Ministry Economic Affairs (DVGW Roadmap for Standardization of Hydrogen) and IEA Hydrogen TCP Task 42 Underground Hydrogen Storage on development areas, DNV has identified the risk of fire & explosion as a key knowledge gap. Therefore, DNV proposes to develop guidelines to further industry understanding and approaches to safety for these topics:

  1. Subsurface failure
  2. Surface failure
  3. Risk mitigation methods
  4. New and repurposed facilities
  5. Pipeline connection failures

Objective

DNV would bring together stakeholders on a 2-year Joint Industry Project (JIP) to develop a European focused and rationalized safety approach for development and operation of salt caverns and porous rock storage for hydrogen. Instead of starting from scratch, the JIP will incorporate industry learnings and insights from natural gas and review the applicability of existing natural gas storage guidance for hydrogen with a focus on fire and explosion consequences and risk mitigation methods. The project will deliver the following value-added benefits:

  1. Objective and impartial study
  2. Various design scenarios rather than a site-specific study, e.g. salt caverns/ porous rock storage, onshore/offshore, different layouts, multiple caverns/wellheads, well diameters, type of equipment, confinement, congestion
  3. Various operational ratings and conditions, e.g. storage capacity, pressure, flow rates
  4. Sensitivity study of uncertainties, e.g. immediate vs delayed ignition, overpressure generation by ignition of unconfined hydrogen clouds
  5. Input to demonstrate adherence to the SEVESO III Directive / COMAH / OSD regulations, and land use planning
  6. How do numerical models for natural gas need to be adapted to accurately simulate H2 events?
  7. Identification of potential testing to validate numerical models beyond their applicability envelope.

Approach

The scope would consist of Phase 1 and Phase 1 Extension. Phase 1 would focus on data gathering, assessment of state-of-the-art practices, scenario and threat assessment, identification of uncertainties, consequence impact assessment, and gap analysis of standards and practices. This would be followed by development of risk mitigation methods for new-build and repurposed facilities, evaluation of their effectiveness, ideas for extra requirements for hydrogen storage to address gaps and guideline development. The Phase 1 Extension (subject to additional partners) could include further analysis, potential testing, or other topics as directed by the steering committee.

Project details

The project kicks off in January 2026 with the aim to understand uncertainties and prioritize what topics / R&D (e.g. testing) to address first, understand design implications and mitigation options from a safety/major hazard perspective, give confidence that the risks are well understood for the unique nature of hydrogen geological storage, provide security and confidence in future decarbonization investment decisions, facilitate risk-based decisions for hydrogen geological storage and adherence to regulatory requirements, facilitate certification, and give participants the opportunity to influence best practice. Companies interested in participating are invited to request a formal proposal.

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