The European Commission’s hydrogen strategy acknowledges the potential future need for transporting hydrogen over long distances throughout Europe. Two main options are considered for connecting supply and demand by transporting hydrogen: building new hydrogen-carrying pipelines or repurposing existing natural gas pipelines for transporting pure hydrogen.
The European Union Agency for the Cooperation of Energy Regulators (ACER) reviewed more than 20 studies focusing on the technical and the cost aspects of repurposing existing gas infrastructure to pure 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.
Based on the studies, ACER developed a summary paper on the technical possibilities for repurposing, reflecting on the technical and hydrogen market conditions that could trigger the repurposing of natural gas pipelines to pure hydrogen.
ACER found that repurposing is feasible and 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.
The studies also draw attention to the suitability of salt cavern facilities for storing hydrogen, noting that these facilities are geographically clustered in selected areas in a few EU Member States.
Looking at ways of hydrogen transportation ACER pointed out that similarly to natural gas, trucks and ships can also transport pure hydrogen adding that in all cases, distance and volume are the main drivers determining the most cost-efficient mode of transportation. However, at this time, transporting pure liquefied hydrogen by ship is not cost-efficient. Shipping hydrogen as a constituent of ammonia appears to be considerably cheaper.
ACER underlined that studies offer divergent visions of the future extent of pure hydrogen networks. These visions range from a large-scale, pan-European backbone transmission infrastructure primarily based on repurposed natural gas networks, to regional, cluster-like systems handling hydrogen supply and demand in closer geographic proximity. 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.
At the same time repurposing to hydrogen may be conditional on multiple factors such as the presence of loop (parallel) lines in natural gas pipeline systems, so that at least one string could be repurposed to pure hydrogen, ensuring the security of natural gas supply to consumers during the conversion phase to pure hydrogen and hydrogen market uptake in the area serving a pure hydrogen corridor.
As ACER pointed out it is still uncertain when and where these conditions for repurposing would be met across Europe and whether they will be met at all. Following a cautious approach in the implementation phase of pure hydrogen corridors seems to be a reasonable strategy, where repurposing would be triggered by compelling hydrogen market commitments and demand expectations.
ACER said it will continue discussing the repurposing outlook with energy regulators and stand ready to exchange views with all stakeholders to deliver on the decarbonisation targets, as well as ensuring cost-efficient and cost-effective solutions to the benefit of energy consumers.