In focus: A case for a European offshore hydrogen backbone

300 terawatt hours (TWh) of green hydrogen could potentially be produced using electricity from offshore wind farms in the North Sea by 2050, and used not only to decarbonize hard-to-abate sectors but also to boost the security of energy supply in Europe, a new study has shown.

The “Specification of a European Offshore Hydrogen Backbone” study, commissioned to DNV by infrastructure system operators GASCADE and Fluxys, has highlighted the significant advantages of an offshore hydrogen backbone in the North and Baltic Seas.

Given the lower costs of hydrogen transmission compared to electricity and the possibility for large pipelines to aggregate offshore hydrogen production from several wind farms, the report assesses that offshore hydrogen production is an attractive option for offshore wind production, certainly at distances of more than 100 kilometres from shore.

The potential energy generation from offshore wind in the North Sea and Baltic Sea is immense, and possible greater than what the electricity system alone can handle, according to the study. The DNV study finds that offshore hydrogen production connected by pipeline is cheaper than onshore hydrogen production.

”What we see is that areas located over 100 km from the coastline offer lower levelized costs of production. At this distance, it costs more per energy unit to transport electricity than to carry hydrogen via pipeline,” said Claas Hülsen, Regional Advisory Business Development Director for Energy Systems at DNV – one of the study’s authors.

With regards to transport infrastructure, the study draws two different pictures based on location. For the North Sea, a large area and production potential meet the 100-kilometre criterion. To bring the hydrogen produced offshore to land, a meshed pipeline connection – a European backbone – could sensibly connect production sites to the existing onshore pipeline network, the study shows.

The situation is somewhat different in the Baltic Sea region, where fewer areas currently meet the 100-kilometre criterion. However, if Sweden and Finland decide to produce hydrogen on a large scale and transport it to demand centers in southern Europe, a combined pipeline is likely to make sense there as well.

The spatial distribution of the potential offshore hydrogen production sites has shown that the sea areas of different countries are involved.

”This suggests that transnational coordination will be necessary to develop the full identified hydrogen generation potential,” said Christoph von dem Bussche, Managing Director of GASCADE.

The study points out that striking the right balance between the potential use of wind for electricity generation and the potential generation of hydrogen across countries will be equally as important.

To further optimize this hydrogen supply chain, the study suggests storing up to 30 per cent of the produced hydrogen in salt caverns to efficiently increase the flexibility of the system.

To support the political discussion, the study also contains an initial cost estimate. In the North Sea, the cost of pipelines and compressors for the offshore hydrogen backbone is estimated to account for ten per cent of the total cost of hydrogen produced offshore. According to initial calculations, a hydrogen system costs for the North Sea of €4.69-4.97/kg can be achieved with an investment in offshore hydrogen transport infrastructure of €35-52 billion, including underground storage.

The study is said to strenghten GASCADE and Fluxys in their conviction that the AquaDuctus project is a key building block to achieve a green transition and meet the decarbonization targets of the EU Green Deal and Repower EU package.

This large-scale offshore pipeline project, conceived to efficiently carry hydrogen produced from wind farms in the North Sea onto the German onshore hydrogen grid, is indeed designed as a backbone able to collect hydrogen from multiple production sites while also offering the potential to link up with other international hydrogen flows through the North Sea.

Pascal De Buck, CEO of Fluxys, said: ”The AquaDuctus offshore pipeline, thought as a regulated open access infrastructure available to all future operators of hydrogen wind farms, will make a substantial contribution to security of supply by diversifying Europe’s hydrogen supply sources.”

As mentioned, offshore hydrogen could serve multiple purposes, from helping secure the energy supply in Europe, to decarbonising hard-to-abate sectors such as shipping where major companies are making preparations for fossil fuel-free operations.

DNV’s study focuses on green hydrogen generated with electricity from offshore wind farms, However, it is not out of the question that by 2050 nascent technologies such as floating solar, tidal energy, and wave energy will reach the level of maturity needed and also be used in the production of offshore hydrogen.