The EU Agency for the Cooperation of Energy Regulators (ACER) conducted a review of numerous studies focusing on the technical and the cost aspects of repurposing existing gas infrastructure for hydrogen. The analysed studies range across various sources and stakeholders, including the gas industry, multi-partner hydrogen initiatives, industry partnerships, academia, think tanks and others.

As a result, ACER developed a summary paper on the technical possibilities for repurposing based on the available studies. The paper also offers a reflection on the technical and hydrogen market conditions that could trigger the repurposing of natural gas pipelines to pure hydrogen.

What are the main findings?

1. Repurposing is cheaper than building from scratch: as a rule-of-thumb, repurposing does not present insurmountable technical challenges and is cheaper than building new pure hydrogen networks.

2. Ways of hydrogen transportation: similarly to natural gas, trucks and ships can also transport pure hydrogen. In all cases, distance and volume are the main drivers determining the most cost-efficient mode of transportation.

3. Future pure hydrogen networks: studies offer divergent visions of the future extent of pure hydrogen networks. However, several studies conclude that, based on industrial hydrogen demand, technology and cost assumptions, there is no indication that a large-scale pan-European hydrogen network would be justified.

4. Repurposing for hydrogen may be conditional on:

• the presence of loop (parallel) lines in natural gas pipeline systems, so that at least one string could be repurposed to pure hydrogen,
• ensuring security of natural gas supply to consumers in the conversion phase to pure hydrogen,
• hydrogen market uptake in the area serving a pure hydrogen corridor.

Currently, it is uncertain when and where these conditions for repurposing would be met across Europe, and whether they will be met at all.

ACER and energy regulators will continue discussing the repurposing outlook and stand ready to exchange views with all stakeholders, with the goal of delivering the decarbonisation targets, as well as ensuring cost-efficient and cost-effective solutions to the benefit of energy consumers.