Why floating hydrogen is a game changer for the renewable industry
Victor Liu, Ph.D.
The seemingly odd concept of combining two expensive nascent technologies, floating wind and green hydrogen, can bring cost benefits and scale potentials that could change the industry landscape of renewables.
The idea of combining floating wind and green hydrogen might sound odd. Both are high-cost nascent technologies that are not commercially deployed yet.
Electricity generated by floating wind now cost around $200 per megawatt, 3 times higher than power produced by fixed offshore turbines. And green hydrogen, which is derived from splitting water using renewable electricity, comes with a cost of $5 per kilo, which is also 3-4 times higher than conventional hydrogen produced by fossil fuels.
Yet, the idea of floating hydrogen is gaining momentum in Europe. Government authorities in the UK, France, Spain and Germany have kicked off research projects for floating hydrogen and its supply chain. The countries have also supported a number of demonstration projects that are working on full-scale prototypes.
And many have claimed enormous market potential for this idea. Last year a report from the Offshore Wind Industry council (OWIC) suggested that offshore hydrogen not only has a potential to replace natural gas demand for the entire UK, but also to make the country a hydrogen export hub for the continent Europe. One example – ERM’s Dolphyn project is looking at a $15bn deployment of 4GW of floating hydrogen in the UK by 2032, which could heat up 1.5 million homes close by.
Cost benefits
Let us first look at floating hydrogen from a cost perspective, which is paramount to the commercial viability of the concept.
First, although costs of floating wind and green hydrogen seem forbidding for now, a steep learning curve is expected for both. Many in the industry are in firm believe that the same forces of rapid innovation and scaling-up that drove down renewable costs by 80% over the past 10 years, will also apply to floating wind and green hydrogen solutions.
Bloomberg NEF recently forecast an 80% fall in the cost of green hydrogen by 2030, opening the way for its widespread use as a carbon-free fuel. Separately, EMR last year predicted that a fall-scale floating hydrogen plant to be deployed in 2032 can produce hydrogen at $1.41/kg, comparable with projected wholesale natural gas prices in Europe.
Second, by equipping floating turbines with on-board hydrogen plant and energy storage unit, floating hydrogen can be completely independent of the power grid. This removes the need for complex, expensive electrical infrastructure that would dominate the costs when projects become increasingly farther from shore. The associated high-cost electrical equipment includes electric cables, switchgears, substations, and grid connections.
And without electricity connection to shore, a self-sufficient floating wind project does not come with a pressure of volatile electricity pricing and concerns of grid capacity.
Third, floating hydrogen can leverage existing oil and gas infrastructure bases such as platform and pipelines of the offshore oil industry.
For instance, potential wind development zones in the North Sea will be a familiar territory for the oil and gas supply chain, which has been constructing and servicing platforms for over 50 years in the waters. Dolphyn said that it is talking to a "major oil company" about repurposing an existing pipeline for hydrogen export.
Scale enabler
Beyond costs, floating hydrogen is also seen as a scale enabler for the renewable industry to tap into rich wind resources in remote sea areas that are not contemplated to date.
Freeing the windfarm from the constraints of grid makes it easier to build large scale projects further out to sea, without incurring environmental concerns or impacting shipping routes.
And deep, remote waters also possess excellent wind resources, which could translate into high yield of energy production. In the UK, OWIC believes that offshore development opportunities in the country is far larger than the 75GW planned by the authorities. And new technologies such as floating wind and green hydrogen can help to unlock a potential of more than 600GW of wind resources far out in the North Sea.
In addition, the open sea provides vast space as well as unlimited water, which is a crucial feedstock for green hydrogen. These favourable characteristics make possible energy solutions with creative designs. For instance, Acciona's OceanH2, a floating hydrogen demonstration project, will use a twin-turbine floating platform from Hexicon wired together with a floating solar system to produce hydrogen in deepwaters off Spain. It will be the world's first green hydrogen plant powered by a floating hybrid electricity generation system.
Optimal solution
Indeed, apart from some basic principles (such as in-field hydrogen plants rather than an onshore centred one), the design of the floating hydrogen system can be quite project-specific as there is no one-size-fits-all solution. The optimal pathway of a system will depend on individual site's met-ocean conditions, resource characteristics, distance to shore, availability of adjacent infrastructure, proximity to consumption hubs etc.
For instance, Acciona's incorporation of floating solar into its generation system is aimed at utilising rich solar resources in Spain, whereas in the North Sea the OWIC suggested retrofitting oil and gas platforms to accommodate hydrogen plants and maintenance facilities. In the future, additional resources on site such as wave, tide and ocean energy could also be considered to further improve system yield and cost effectiveness.
In terms of output solutions, hydrogen produced by floating hydrogen plants could be pumped back to shore, loaded onto shuttle tankers for transportation, or used as fuel for green shipping in the future. The specific choice would be region and project specific. For instance, in the North Sea, piping hydrogen back to shore makes good sense, as the region already has an extensive subsea pipeline infrastructure in place.
In short, floating hydrogen could enable efficient use of almost unlimited resources and unlock versatile applications that are previously unthinkable. In that sense, floating hydrogen has the potential to become a game changer for the renewable industry.
That said, despite the bright prospects, the road to utility-scale development of floating hydrogen is still 10 years away from us and several challenges will need to be confronted in the meantime.
These include common issues associated with nascent technologies such as cost barriers and supply chain readiness. Just like what we have seen in solar and offshore wind, these challenges can be solved through effective public-private initiatives and industry collaborations.
But there is a hydrogen-specific problem that needs to be addressed as soon as possible – there is not a ready market to consume it yet. Blending hydrogen into gas pipelines, promoting hydrogen fuel, or developing industry applications cannot be done rapidly through market forces alone at this stage. Government authorities need to take it one step further to kick off a virtuous demand-supply circle for the promising clean gas produced by floating hydrogen plants.ke it one step further to kick off a virtuous demand-supply circle for the promising clean gas produced by floating plants.