Green hydrogen from offshore wind and its vital role in our Net-Zero future

By Simon Cheeseman from Marine-i Partner, Offshore Renewable Energy (ORE) Catapult

The UK has outstanding offshore wind resources, with the potential for over 600GW in our waters and potentially up to 1000GW. This is well above the figure of 75-100GW that is likely to be needed for UK electricity generation by 2050.

So that begs the question, when offshore wind is producing more electricity than is required for the grid, what could we use this excess power for?

This is not a new question. Previously, it had been examined from the viewpoint of grid efficiency, i.e. when there is a short-term ‘overproduction’ of energy, how can this valuable output be saved? Could it be stored in giant batteries for later use, or diverted for other uses?

Today, a much more exciting prospect is occupying the minds of offshore specialists. This is the potential for wind farms to be used to produce hydrogen from seawater. From a theoretical standpoint, this is a relatively simple process. Wind turbines could be fitted with desalination equipment to remove the salt from seawater. Then electrolysis would be used to split the resulting fresh water into oxygen and hydrogen.

Many people view hydrogen as the perfect fuel for the future. Whether it is used in a hydrogen fuel cell to power a car or burned to create heat for homes, the only “emission” it gives off is water vapour. So the more we make use of hydrogen, the more potential we have to slow down the effects of global warming. 

Added to this, “green hydrogen” produced from renewable energy would be much more environmentally-friendly than that produced from other sources such as fossil fuels (so-called “blue hydrogen”). With offshore wind costs continuing to fall, green hydrogen costs could be competitive with blue hydrogen by the early 2030s. 

All of this is pointing toward a massive worldwide market for green hydrogen that could emerge over the coming decade – and one that plays to the UK’s strengths.

In addition to our wind energy resources and expertise, the technical know-how of the UK oil and gas industry gives us a further strength to build on, as does the research talent within our universities, who have world-leading capabilities in engineering for electrolysers, fuel cells and hydrogen. The UK is also home to some of the leading designers and manufacturers of hydrolysers.

While all this gives us a powerful platform for development, there are many technical challenges to overcome. Producing hydrogen at scale in a harsh offshore environment has not been done before and will require a number of large trial projects to refine the approach and to prove its reliability – which in turn will require significant upfront investment. 

Once produced, the way in which hydrogen offtake is managed, how the hydrogen is stored, and the way in which it is transported to shore will need innovative thinking from our very best designers and engineers. And hydrogen is a very challenging chemical to transport and store. Unless it is combined with other chemicals, it must be refrigerated to minus 253 degrees Celsius, or compressed to 700 times atmospheric pressure.

Beyond the challenge of production, there is another vital component to the success of green hydrogen – and that is the creation of a market for this new form of energy.

Strategic planning on a national scale will be required to ensure that there is an effective route to market for green hydrogen. That means finding a way to use green hydrogen as the primary heating fuel for businesses and homes and the primary fuel for cars and other forms of transport – with all the supply and delivery infrastructure that this entails. The first step on this journey will be the near-term creation of hydrogen hubs around large industrial clusters.

The potential prize for the UK, as a result of all the above efforts, would be huge. Industry forecasts show that green hydrogen from offshore wind could deliver the following:

• A major new manufacturing sector for the UK
• A UK demand for hydrogen by 2050 at a level between 100-300TWh. This would be of comparable scale to the UK’s entire electricity system today
• By 2050, hydrogen would make up 25% of Europe’s energy supply – with massive further demand globally
• Additional offshore wind development, together with electrolyser manufacture, could generate over 120,000 new jobs – replacing those lost in conventional high carbon industries such as oil and gas
• By 2050, the cumulative gross value added (GVA) from the supply of electrolysers and additional offshore wind farms is up to £320 billion, the majority from exports of hydrolysers to overseas markets
• UK exports of green hydrogen to Europe alone could reach an annual value of £48 billion
• The majority of the new UK jobs created by this new industry would be based in regions outside of London and the South-East, bringing economic growth to the areas that need it the most

Prof Lars Johanning from University of Exeter, Programme Director for Marine-i, has highlighted the huge opportunity for businesses in Cornwall. He said: “Innovative businesses from the marine tech industry and from other related sectors will be a crucial driving force behind this new opportunity. That is why green hydrogen will be a major theme running through many of Marine-i’s activities in the near future. A Discovery Room event will be held on 4th March to explore this exciting opportunity.” Register for the event here.

If you would like to discover more about offshore wind and green hydrogen, you can read a strategic report prepared by the Offshore Wind Industry Council and ORE Catapult called Offshore Wind and Hydrogen: Read the 'Solving the Integration Challenge' document here.

Photo credit: ORE Catapult