Each pink and blue have been used to distinguish between different methods of hydrogen production.
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From Tesla’s Elon Musk to European Commission President Ursula von der Leyen, the past few years have seen many high-profile names talk in regards to the role hydrogen may — or may not — play within the planet’s shift to a more sustainable future.
Musk has expressed skepticism about hydrogen’s usefulness, but many think it could help to slash emissions in a variety of sectors, including transportation and heavy industry. Â Â
While there’s a serious buzz about hydrogen and its importance as a tool in securing a low-carbon future — a subject that is generated lots of debate in recent months — the overwhelming majority of its production continues to be based on fossil fuels.
Indeed, in keeping with a Sept. 2022 tracking report from the International Energy Agency, low-emission hydrogen production in 2021 accounted for lower than 1% of world hydrogen production.
If it’s to have any role within the planned energy transition, then hydrogen generation needs to vary in a reasonably large way. Â Â
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“The very first thing to say is that hydrogen doesn’t really exist naturally, so it needs to be produced,” said Rachael Rothman, co-director of the Grantham Centre for Sustainable Futures on the University of Sheffield.
“It has lots of potential to assist us decarbonize going forwards, but we want to search out low-carbon ways of manufacturing it in the primary place,” she said, adding that different methods of production had been “denoted different colours.”
“About 95% of our hydrogen today comes from steam methane reforming and has a big associated carbon footprint, and that is what’s called ‘grey’ hydrogen,” Rothman told CNBC.
Grey hydrogen is, in keeping with energy firm National Grid, “created from natural gas, or methane.” It says that the greenhouse gases related to the method should not captured, hence the carbon footprint that Rothman refers to.
The dominance of such a technique is clearly at odds with net-zero goals. Consequently, an array of sources, systems and colours of hydrogen are actually being recommend as alternatives.
These include green hydrogen, which refers to hydrogen produced using renewables and electrolysis, with an electrical current splitting water into oxygen and hydrogen.
Blue hydrogen, then again, indicates the usage of natural gas — a fossil fuel — and carbon capture utilization and storage. There was a charged debate across the role blue hydrogen could play within the decarbonization of society.
Pink potential
Alongside blue and green, one other color attracting attention is pink. Like green hydrogen, its process incorporates electrolysis, but there is a key difference: pink uses nuclear.
“When you split … water, you get hydrogen and oxygen,” Rothman said. “But splitting water takes energy, so what pink hydrogen is about is splitting water using energy that has come from nuclear.”
Which means “the entire system is low carbon, because … there is no carbon in water … but in addition the energy source can be very low carbon since it’s nuclear.”
Alongside electrolysis, Rothman noted that nuclear may be used with something called a thermochemical cycle.
This, she explained, harnessed very high temperatures to separate water into oxygen and hydrogen.Â
Pink hydrogen already has some potentially significant backers. These include EDF Energy, which has floated the concept of manufacturing hydrogen at Sizewell C, a 3.2-gigawatt nuclear power station planned for the U.K.
“At Sizewell C, we’re exploring how we will produce and use hydrogen in several ways,” the firm’s website says. “Firstly, it could help lower emissions during construction of the facility station.”
“Secondly, once Sizewell C is operational, we hope to make use of among the heat it generates (alongside electricity) to make hydrogen more efficiently,” it adds.
EDF Energy, which is a component of the multinational EDF Group, said in an announcement sent to CNBC: “Hydrogen produced from nuclear power can play a considerable role within the energy transition.”
The corporate also acknowledged there have been challenges facing the sector and its development.
“Hydrogen is currently a comparatively expensive fuel and so the important thing challenge for low carbon electrolytic hydrogen, whether produced from renewable or nuclear energy, is to bring down the prices of production,” it said.
This needed “supportive policies which encourage investment in early hydrogen production projects and encourage users to modify from fossil fuels to low carbon hydrogen.”
“Growing the marketplace for low carbon hydrogen will deliver the economies of scale and “learning by doing” which can help to scale back the prices of production.”
While there may be excitement in regards to the role nuclear could play in hydrogen production and the broader energy transition — the IEA, for instance, says nuclear power has “significant potential to contribute to power sector decarbonisation” — it goes without saying that it isn’t favored by all.
Critics include Greenpeace. “Nuclear power is touted as an answer to our energy problems, but in point of fact it’s complex and hugely expensive to construct,” the environmental organization says. “It also creates huge amounts of hazardous waste.”
A multi-colored future?
During her interview with CNBC, the University of Sheffield’s Rothman spoke in regards to the greater picture and the role several types of hydrogen might play. Could we ever see a time when the extent of blue and gray hydrogen drops to zero?
“It depends how long a timeframe you are looking at,” she said, adding that “in a really perfect world, they are going to eventually drop very low.”
“Ultimately, we ideally do away with all of our grey hydrogen, because grey hydrogen has a big carbon footprint and we want to do away with it,” Rothman said.
“As we improve carbon capture and storage, there could also be an area for blue hydrogen and that is yet to be evaluated, depending on the … developments there.”
“The pink and green we all know there needs to be an area for because that is where you actually get the low carbon [hydrogen], and we understand it needs to be, it’s possible to get there.”
Fiona Rayment, chief scientist on the UK National Nuclear Laboratory — which, like EDF Energy, is a member of trade association Hydrogen UK — pressed home the importance of getting a variety of options available within the years ahead.
“The challenge of net zero can’t be underestimated; we’ll have to embrace all sources of low carbon hydrogen generation to interchange our reliance on fossil fuels,” she told CNBC.
While there was lots of discuss using colours to distinguish the varied methods of hydrogen production, there may be also a full of life discussion about whether such a classification system should even exist in any respect.
“What we wish is low carbon hydrogen,” Rothman said. “And I do know there may be lots of confusion in regards to the various colours, and I’ve heard some people say … ‘why will we even have the colours, why will we not only have hydrogen and low carbon hydrogen?'”
“And ultimately, it is the low carbon bit that is essential, and each pink and green would try this.”
