A hydrogen economy will need vast amounts of low-carbon electricity to power electrolysis, possibly offering nuclear power renewed opportunities in a decarbonised world
NEW MARKETS Large amounts of low-cost, low-carbon electricity will be needed for hydrogen electrolysis
NUCLEAR QUESTION Deep-rooted concerns over new nuclear power still stand
KEY QUOTE Hydrogen production is potentially a very large market for low-carbon energy sources such as nuclear
The imposing Oskarshamn nuclear power plant, bordering the Baltic Sea, has been delivering electricity to the Swedish grid since the early 1970s. But as its third and final reactor has been at work since 1985, and with two earlier reactors long since retired, the power plant is very much a symbol of Sweden’s energy past. In January 2022, however, Oskarshamn became linked to Europe’s energy future, through an agreement to supply low-carbon hydrogen to UK-based chemical giant Linde Gas for use in applications formerly dominated by fossil fuels. The agreement will see Oskarshamn’s operator, Swedish corporation Oskarshamns Kraftgrupp (OKG), use some of the low-carbon electricity produced by the plant’s existing reactor for electrolysis, creating hydrogen and oxygen from water. Demand for such low-carbon hydrogen is on the rise. Clean-burning gas is seen as a potential replacement for fossil fuels in a range of applications, from transportation to heavy industry. The nuclear sector is keen to carve out a niche for itself in this emerging market.
COLOURFUL GAS The key to hydrogen’s viability within decarbonisation efforts depends on it being made with few or zero carbon emissions and at low cost. Several hydrogen production pathways are available, each assigned a colour to differentiate it from others. Most of today’s hydrogen for existing applications is produced via a carbon-intensive steam methane reforming process. This is known as “grey hydrogen”. If grey hydrogen’s carbon emissions are captured and stored, then it is classed as “blue hydrogen”. If produced with renewables-powered electrolysis, it is called “green hydrogen”. Where nuclear energy is used to power production, the result is “pink hydrogen”. (It is important to remember these colours simply represent different production techniques. The gas itself is always colourless.) Members of the nuclear industry, which has been struggling in recent years under the impact of lower-cost natural gas and renewable energy in key European and North American markets, believe pink hydrogen could be an important source of future growth. “Some estimates project that energy requirements for hydrogen production could eventually exceed energy requirements for electricity generation,” says Jonathan Cobb of the World Nuclear Association, an industry body. “Hydrogen production is therefore potentially a very large market for low-carbon energy sources such as nuclear,” Cobb adds.
PINK PATHWAYS Nuclear power plants could create pink hydrogen through four separate pathways: cold electrolysis, low-temperature steam electrolysis, high-temperature steam electrolysis and high-temperature thermochemical production. The first of these is the process being used at Oskarshamn. Steam electrolysis could improve the efficiency of hydrogen production by using a reactor’s heat as well as its electricity, although the high-temperature version has yet to be commercialised. Similarly, high-temperature thermochemical production is expected to be even more efficient, but “is at an even earlier stage of development,” Cobb says. Being at an early stage of development describes all pink hydrogen production generally. It was relatively easy to do at Oskarshamn because the plant had already been producing hydrogen using an electrolyser installed in 1992. The gas was added to its reactor coolant as a way of preventing pipes from cracking. The electrolyser was originally sized to serve three reactors. So, after Oskarshamn’s first two reactors shut down, in 2016 and 2017, it was producing more hydrogen than the plant needed. The production capacity today is just 12 kilograms of hydrogen an hour. OKG expects to increase that capacity with a modernisation programme that is currently underway.
UK PLANS Other moves to investigate pink hydrogen production are ongoing. In the UK, energy company EDF Energy—part of French state-owned Électricité de France (EDF)—is planning to produce hydrogen from its Sizewell B nuclear reactor in east England to replace some of the fossil fuels that might be needed to build a new reactor at the site. Assuming the new nuclear plant Sizewell C goes ahead, EDF Energy could use some of its heat for steam electrolysis. “By linking to other low-carbon technologies, like hydrogen, it will be able to operate more flexibly and deliver even more value to the energy system,” says EDF Energy. Support for EDF Energy’s approach comes from the Nuclear Industry Council, a joint forum between the nuclear industry and the UK government. In 2021, the Council published a roadmap claiming nuclear power could meet a third of the UK’s clean hydrogen needs by 2050.
CHANGING ATTITUDES Elsewhere, operators in the United States are investigating pink hydrogen production at the Palo Verde nuclear power plant in Arizona. Meanwhile, state-owned developer Emirates Nuclear Energy Corporation is considering a similar move having commissioned the Middle East’s first commercial reactor at Barakah, in the western region of Abu Dhabi, in 2020. Despite well-documented setbacks to nuclear plants under development in Europe and the US, the appetite for building new reactors has improved in recent months as leaders have sought to put in place ambitious measures to cut carbon emissions. In France, President Emmanuel Macron pledged to build at least six new reactors as part of moves to make the country carbon neutral by 2050. The UK government is also standing by plans to boost its nuclear fleet, a sentiment strengthened after the war in Ukraine raised concerns over Europe’s reliance on Russia oil and gas. Some experts see clear synergies in marrying new nuclear capacity with hydrogen. “We need new forms of low-carbon electricity to produce hydrogen,” Dutch MEP Bart Groothuis told a Euractiv media network in 2021, citing low-carbon hydrogen coming from nuclear power plants. Meanwhile, a September 2021 study by Aurora Energy Research, a UK-based analyst firm, sponsored by the atomic energy industry, found net-zero emissions pathways using renewables and nuclear for power and hydrogen could cut total system spending up to 9%. One part of the nuclear industry that is particularly keen on the hydrogen opportunity is the small modular reactor (SMR) segment. 
THINKING SMALL SMRs are an emerging technology class of modern reactors that are typically smaller in size than legacy plants and are intended to be built in manufacturing facilities rather than on-site, features which proponents hope will cut costs. Although SMRs have yet to be commercialised in western markets, manufacturers are keen to highlight possible use cases for their technology. US developer NuScale Power has even gone so far as to publish evaluations of how its SMR design could cut the cost of pink hydrogen production by using waste heat for high-temperature steam electrolysis. “Hydrogen produced by a high-temperature steam electrolysis system is forecast to be cost-competitive with high-capacity-factor renewable hydrogen cost estimates while providing continuous, controlled production,” says the firm. “The high-temperature heat produced by the reactors can be directly used to produce hydrogen, thus reducing efficiency losses from only utilising electricity alone for hydrogen production through electrolysis,” adds NuScale Power’s Diane Hughes.
PR EXERCISE In February 2021, a study by the international consultancy Lucid Catalyst forecast that SMRs would be able to deliver hydrogen at a cost of $1.10 per kilogram, dropping to $0.90 per kilo by 2030. This is cheaper than grey hydrogen production today, which makes new nuclear sound like a boon for the hydrogen economy. But not everyone is convinced. Nuclear sceptic and academic David Toke, of the University of Aberdeen, says, in the UK at least, it would not make much sense for new plants to produce hydrogen because they are being guaranteed better rates for electricity production. “My view is that this will end up being little more than a public relations exercise by the nuclear industry,” he says. “For contractual and operating reasons, they’re going to focus on generating electricity—not producing hydrogen, for which they will get much lower income.”
CONSTRUCTION OVERRUNS A challenge for the nuclear industry’s hydrogen hopes is the length of time it takes to build new reactors. Olkiluoto 3, a new reactor that came online in Finland in March 2022, took 17 years to build, while at Flamanville 3, another unit of the same design in France, construction started 15 years ago and fuel loading is not expected until 2023. Both reactors have also seen cost overruns. The outlay for Flamanville 3 is expected to be more than four times its original estimate while the price tag for Olkiluoto 3 ballooned from €3 billion to €11 billion. There are hopes such cost and schedule overruns could be avoided in future, either by using SMR or by harnessing economies of scale that might come from a new-build programme such as that planned for France. However, based on the experience to date it is fair to question whether any new reactors will come online in time to make much of a difference to low-carbon hydrogen production in the push to cut net emissions to zero by 2050. Even if new reactors do make it online in time, it remains to be seen how competitive they will be with alternative low-carbon generation sources, particularly in view of the spectacular falls seen in solar and wind costs. 
DIFFERENT APPROACH Perhaps because of this, EDF, which operates 58 reactors in France and is responsible for finishing Flamanville 3, has a more sober view of pink hydrogen. The company has not dismissed plugging an electrolyser directly into a nuclear power plant, but “The approach today is to connect electrolysers to the electricity grid,” says EDF’s Marion Labatut. This makes sense in France because the grid is already low in carbon. Thanks largely to the predominance of nuclear power in the electricity network, the carbon intensity of the grid was just 57.3 grams of CO2 per kilowatt-hour in 2020. This compares to a range of between 87 and 664 grams of CO2 per kilowatt-hour in Germany. Hence, feeding electrolysers directly with grid supplies in France can yield relatively low-carbon hydrogen without the need for dedicated generation. Furthermore, the grid-attached approach allows electrolysers to be located close to places where hydrogen will be used, such as industrial clusters or chemical plants. This is important because hydrogen is not easy to store or transport. Since the gas is complex to handle, reducing the need for storage and transport also reduces the costs involved in using hydrogen. “You can plug your electrolyser anywhere you want, close to the consumer,” adds Elodie Perret of EDF.
GROWING OPPORTUNITY Clearly, France is in quite a unique position in being able to make low-carbon hydrogen from grid electricity. However, there are already some other European nations, such as Finland, Norway and Sweden, that could meet Europe’s definition for sustainable hydrogen—where three kilos or less of CO2 are produced per kilo of hydrogen—using grid supplies. More will join the list as states rush to decarbonise their grids, with at least seven European member states expected to meet Europe’s threshold for sustainable hydrogen production from grid supplies, most of the time, by 2030. The upside of EDF’s approach is that it allows sustainable hydrogen production to scale directly alongside growing low-carbon generation capacity.
MULTIPLE BENEFITS Grid-connected electrolysers also help to absorb increasing amounts of renewable energy because any excesses can be used to power electrolysers instead of being curtailed. This is true even in nuclear-heavy grids like France’s. Ordinarily, French reactors might be forced into load-following mode in the face of a big influx of renewables. This is not something the nuclear plants were designed for. With grid-connected electrolysers, however, the nuclear plants could maintain a steady output and any excess renewable energy could be diverted to electrolysis. A whole-grid concept makes it perfectly possible for nuclear to contribute to hydrogen production but will not lead to a shortfall of clean power for electrolysers if market forces fail to spawn new reactors. Nor will it penalise nuclear plants that get delayed in construction, since low-carbon hydrogen demand will likely continue to grow beyond 2050. “We think it’s much more efficient to have this systemic approach rather than saying this specific nuclear power plant has to be available all the time for this electrolyser,” Labatut says. •
TEXT Jason Deign