Electrolysis in the North Sea: our role and the role of green hydrogen

In the Netherlands, the North Sea is indispensable in our transition to sustainable energy. Offshore wind turbines are an essential element in this, both for generating wind energy and for producing green hydrogen from seawater. The latter involves a process called electrolysis. But how does it actually work? And what is Gasunie’s role in this?

There are enormous wind turbines in the North Sea that capture the power of the wind and convert it into electricity. To produce hydrogen, water is transported to an electrolyser. This system starts a chemical process called electrolysis. In the electrolyser, electricity is used to split the water into two parts: hydrogen (H₂) and oxygen (O₂). The oxygen is released into the air leaving behind just hydrogen, ready for immediate use. This hydrogen can be fed directly into the (yet-to-be-built) pipeline network.

Producing hydrogen offshore has several advantages. Firstly, this approach enables a direct connection between the offshore wind farms and the electrolysers, meaning that hydrogen can be produced at locations close to the wind farms. This reduces the need to transport the power generated to land over long distances via cables.

Secondly, hydrogen is easier to store than electricity. Wind energy is variable and the amount generated depends on weather conditions. By converting electricity into green hydrogen, we can store this energy and use it when demand is high or when the wind is not blowing.

Thirdly, electrolysers take up an enormous amount of space, and land is at a premium. On land, 20 hectares – the equivalent of 40 football pitches – is required to produce one gigawatt of hydrogen capacity. Moving production offshore where possible leaves land available for other purposes. So, the spacious North Sea offers prospects.

The roll-out of offshore hydrogen has reached the development stage. This means that essential research is being carried out and test environments are in operation right now. To continue encouraging these developments, in June 2024 the Dutch Minister of Climate Policy and Green Growth announced that the government would be giving the development of offshore hydrogen production a boost. This is taking shape initially through two offshore demonstration projects: Demo 1 and Demo 2. Gasunie is closely involved in the development of both projects: it is developing the infrastructure to bring hydrogen produced at sea onshore.

Gasunie is working on this infrastructure each and every day. The future hydrogen network must safely bring the offshore hydrogen to landfall points onshore. To make this possible, Gasunie is designing a network that must be able to last for decades, take into account the ecological carrying capacity of the North Sea as much as possible and reuse existing natural gas pipelines wherever possible. This will be driven by future developments. 

To sum it all up, Gasunie does not have a role in the development of producing hydrogen via electrolysis, but is responsible for the future transmission of the hydrogen produced. We are investigating the entire value chain with the aim of creating a system with the lowest possible social costs.

At the moment, apart from pilots and test environments, offshore electrolysis is non-existent. All the same, using electrolysis to produce hydrogen from seawater in the North Sea is a promising development in the energy transition. By connecting wind energy and hydrogen production, we can not only cut emissions, but also ensure a stable, efficient energy supply. This energy is desperately needed if we want to supply the whole of the Netherlands with sustainable electricity in the future. In the end, bringing wind energy onshore both in the form of electricity and hydrogen should help us achieve the Dutch climate objectives.