What is the potential for nuclear-enabled hydrogen?

Can the nuclear sector’s ambitions to meet up to a third of the UK’s future hydrogen demand be realised? Lucinda Dann looks at the potential for nuclear-enabled hydrogen in the UK.

Nuclear energy could produce up to a third of the UK’s total hydrogen requirement by 2050 while bringing a wealth of benefits over other green hydrogen technologies, according to nuclear advocates.

These benefits include reliable year-round generation, reducing the need for inter-seasonal storage, and more efficient hydrogen production using electrolysers. Nuclear power could also provide much-needed flexibility to the electricity system, with reactors switching between hydrogen and electricity production depending on the output from renewable generation.

Nuclear also provides a low-risk option because the technology is already available and could be deployed now, with 3GW of today’s technology capable of meeting 10% of the UK’s 2050 hydrogen target. The next generation of reactors being supported by the government could increase the efficiency of hydrogen production further by using the heat generated by the nuclear process.

But there are barriers to realising this potential, including establishing customer demand for hydrogen in the first place. And while the technology is proven, the cost remains largely unknown. The nuclear industry also faces a sizeable challenge in overcoming negative public opinion if reactors are to be located within industrial clusters to achieve better efficiencies.

Some of these barriers would be addressed by a target from the government, but despite setting an ambition for nuclear to produce up to a quarter of the UK’s power supply by 2050, it has yet to turn to the question of hydrogen.

While the government’s current focus on electricity production is understandable, it will need to move with more “pace and ambition” if the UK is not to miss the boat on realising its ambition for the UK to have a world-leading hydrogen industry.

Such a target must come with a wider strategic view to plan the best locations and uses of nuclear to capitalise on potential efficiencies, and specific funding to support its development.

In 2022 the UK government doubled its targets for hydrogen production to 10GW by 2030, with at least half of this target expected to be electrolytic, or “green” hydrogen. Electrolytic hydrogen is produced through the splitting of water into hydrogen and oxygen using an electric current from a renewable source of energy, such as wind or solar, therefore giving zero carbon emissions.

While having the same carbon status as renewable technologies in the UK, nuclear energy is far better suited to the production of electrolytic hydrogen due to its constant and predictable nature.

“Electrolysers run more efficiently when they have a predictable, reliable and continuous input,” says the Nuclear Industry Association’s director of policy and external affairs Lincoln Hill.

Unlike other sources of green electricity, the primary output of nuclear is clean heat, which can also help improve the efficiency of the electrolysis process.

Last month EDF Energy was awarded £6.1 million of government funding from the Industrial Hydrogen Accelerator Programme to demonstrate the use of solid oxide electrolysis to produce hydrogen at its Heysham nuclear power station near Lancaster (pictured above). One of the aims of the project is to demonstrate how utilising steam from the nuclear reactor could be 20% more efficient than incumbent technologies.

Due to the potential for increased efficiency, cogeneration of the two technologies is desirable, with EDF also looking at hydrogen production at its planned Sizewell site.

But it is the next generation of reactors – both small modular reactors (SMR) and advanced modular reactors (AMR) which offers the most exciting opportunities. SMRs are advanced nuclear reactors that generate only around a third of the output of a traditional reactor, but which employ existing technology. SMRs could be more easily co-located with hydrogen producers due to their size.

Meanwhile the UK is specifically looking to capitalise on its unique history of gas-cooled reactors to develop high temperature AMRs which could operate at close to 1000 degrees Celsius. If the UK was able to develop this technology, it could potentially look at splitting water using a thermal chemical process which would remove the need to first convert heat to electricity, thereby cutting the costs of production.

Despite the many benefits of coupling hydrogen to nuclear generation, the UK government has yet to give the idea its full potential because it has the more immediate problem of expediating a nuclear renaissance in the UK.

Currently nuclear provides some 5.5GW of the UK’s electricity, around 15%, but this will drop drastically by 2028 as eight out of nine operational reactors are retired. In 2022, spurred on by the energy crisis brought about by the Ukraine war, then prime minister Boris Johnson announced a target of 24GW from nuclear power by 2050 and an ambition to build a new reactor every year.

The Science, Innovation and Technology Committee called the target laudable, as it would represent three times the current nuclear capacity even before the planned retirements, and double the highest nuclear capacity the UK has ever achieved.

Hill says the government’s focus on electricity is “understandable” given the UK is expected to double its requirement for electricity by 2050. “It recognises nuclear has the potential, but it hasn’t been defined in a gigawatt target. We have suggested that they try and define it in those terms,” he adds.

While the nuclear industry could feasibly produce hydrogen from today, it would have to use power needed to support the electricity grid. Realistically the industry is unlikely to be large enough to have surplus to support hydrogen production until the 2030s, but ambitious clear decisions need to be made in the 2020s, says Hill.

“That’s the key thing we are trying to get across. Solutions for sustainable, deep decarbonisation, especially of industry, are going to be medium to long term in some senses but you have to start now. If you want to develop what is, compared to others, a relatively immature technology into a mature robust commercially competitive technology then you need to start getting behind it now and putting in place the incentives on both the customer and supplier side to make this happen.”

He hopes that a consultation looking at alternative routes to market for SMR designs not chosen by the recently created development body Great British Nuclear in the competition launched in July will be a vehicle for discussion around a specific hydrogen target and uses for the energy.

However, Celia Greaves, chief executive of the Hydrogen Energy Association says that while a target would be welcome it must be accompanied with specific support for nuclear-enabled hydrogen.

“To ensure that we maximise our chances of reaching net zero, we would like to see existing funding extended in both scale and ambition to include nuclear-enabled hydrogen or for specific support to be created. What we don’t want to be doing is cutting existing pies into smaller pieces.”

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