How hydrogen will power Scotland's just transition from fossil fuels

The Scottish Government aims to have a hydrogen production capacity of five gigawatts (GW) by 2030 – that’s equivalent to 15% of the nation’s energy demand. By 2045, the hope is to increase this five-fold, to a massive 25GW.

Large-scale hydrogen production projects are ­starting to take off across the country, too. Statera Energy’s Kintore Hydrogen project in ­Aberdeenshire is hoping to have 0.5 GW operational capacity of green hydrogen by 2028, and 3GW in the early 2030s. In Shetland, the operators of the Sullom Voe oil ­terminal plan to install 1GW of hydrogen ­production, and the decommissioned nuclear power station at Chapelcross in Dumfries and Galloway is set to be transformed into a hydrogen-based green energy hub.

As a relatively clean-burning fuel (emitting zero carbon dioxide), hydrogen offers an attractive ­alternative for anything which runs on burning fossil fuels – from vehicle engines to gas boilers to industrial processes. Hydrogen is also not as new as we might think – hydrogen derived from fossil fuels has been used in Scotland for decades, for example, to produce the ammonia which goes into fertilisers and cleaning products.

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So where will we be using hydrogen in a net-zero future? While we’ve now developed a wealth of ­low-carbon methods for producing hydrogen, we can’t simply drop hydrogen into our existing ­engines, boilers and pipes. Hydrogen trials in dozens of ­aspects of Scotland’s infrastructure and economy are gradually refining the role of this fuel in Scotland’s decarbonisation.

The North Sea’s new export

THE first answer to where Scottish hydrogen might go is abroad. Northern European countries like the Netherlands and Germany are already using ­hydrogen at an increasing scale, and estimates ­suggest that European demand could absorb up to 74% of Scottish hydrogen production.

Europe is quickly developing infrastructure for ­hydrogen exports and imports, too.

Thirty-three countries across Europe are ­collaborating on the ­European Hydrogen Backbone, which will connect producers and consumers of ­hydrogen across the continent. These pipelines are well under way, with 31,500km set to be operational by 2030.

While the announcement in September that the Norwegian state energy company will scrap its plans for a hydrogen pipeline to Germany has cast doubt on the Hydrogen Backbone vision, the ­German ­government has taken immediate action to find ­alternative supplies. With hydrogen-ready power plants set to be functional as early as 2030, demand for low-carbon hydrogen in Germany is only going to increase.

According to the European Hydrogen ­Observatory, the demand for hydrogen across ­Europe will increase by 51% between now and 2030, and then a further 127% by 2040.

A hydrogen powered bus in Aberdeen In Aberdeen, the Net Zero Technology Centre (NZTC) estimates that Scotland could supply up to 10% of total European hydrogen demand by the ­mid-2030s. NZTC’s Hydrogen Backbone Link ­research, funded by Holyrood, assessed the nuts and bolts of this export route. They found that while it is ­feasible, it’s going to be a mammoth ­project.

Building the pipeline itself is estimated to cost £2.7 billion. The cheaper option of reusing existing oil and gas pipelines was initially considered, but NZTC ­argues that building a new pipeline with the ­ideal materials, valves and diameter is the optimal long-term option.

According to NZTC’s analysis, this pipeline can be cost-effective for ­investors, but the most cost-effective quantity of hydrogen export is far above Scotland’s existing ambitions; starting at 10GW, twice the immediate goal of the Scottish Government.

“The question we originally asked in the Energy Hub project was what have we got and what does it give us … the right question to ask is what do we need and how do we do it,” says Darren Gee, from NZTC.

NZTC estimates that the Scottish ­Backbone Link should be functional –at least in smaller quantities – by 2035, ­if Scotland wants to meet its net-zero ­targets. That means getting projects ­funded and started in the next five years.

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IN the meantime, there are plans to ­develop export markets before the ­pipeline is constructed.

The Scottish Government has already secured memorandums of understanding (MOUs) with Denmark, Hamburg, Bavaria, Occitania, and North Rhine-Westphalia to build hydrogen export markets. The main entry for the pipeline is expected to be at Flotta in Orkney, where small ­exports can be shipped from until the pipeline is finished. Branches of the backbone link are also imagined from Sullom Voe, St Fergus and the Cromarty Firth.

Industry: The bedrock of domestic ­demand

Within Scotland, end-uses for hydrogen are more elusive, but dozens of trials are carving out a niche for ­hydrogen in Scotland’s energy mix.

The most obvious end-use for ­hydrogen produced in Scotland is heavy ­industry.

“The target markets for Kintore ­Hydrogen include high-demand ­industries which ­urgently need to ­decarbonise, such as energy-intensive industrial clusters and power generation facilities,” says Tom Vernon, CEO of ­Statera Energy, the head of the Kintore Hydrogen ­Project.

Cromarty Hydrogen Project – which is also hoped to be operational before 2030 – is being established in partnership with surrounding distilleries, who will be the project’s first buyers.

However, plenty of industrial would-be hydrogen buyers are outside the ­immediate vicinity of hydrogen ­production sites. While hydrogen can in theory be transported by road, ­Vernon ­argues that onshore hydrogen pipelines are needed to connect large-scale ­hydrogen production with these sources of demand.

“We believe a national hydrogen ­network is fundamental to delivering the UK’s hydrogen economy,” he says. “Such a network can effectively and efficiently connect low-cost hydrogen production like Kintore Hydrogen with industrial clusters, storage locations, and key power generation sites.

Many industries are turning to hydrogen as an alternative fuel source (Image: Bristol Airport) “Accelerating the development of a ­dedicated network is essential, as this will allow projects to scale without the reliance on individual producers or offtakers, while also minimising fuel ­transportation costs.” he adds.

There are ambitious plans for a UK-wide hydrogen gas network, completed in the early 2030s.

The 2000km of new and reused pipelines will connect strategic industrial locations to hydrogen production areas. Just this year, trials in Carlisle proved that the existing gas network is capable of transporting hydrogen, but many details remain to be ironed out before this mass infrastructure project hits the ground.

Hydrogen homes: Falling behind other options

WHILE infrastructure is ­racing to catch up with industry demand for ­hydrogen, some trials for hydrogen use have run out of steam. Hydrogen as a ­replacement to mains gas in households, for instance, seems an increasingly ­distant prospect.

While Fife is hosting the world’s first trial of fully hydrogen-powered homes, the 300 hydrogen homes will not be ­completed until 2025 at the earliest.

Down south, the UK Government has put similar trials on hold until 2026, ­stating that “low-carbon ­hydrogen may have a role to play in heat ­decarbonisation alongside heat pumps and heat networks, but in slower time in some locations”.

Given the readiness of other solutions, hydrogen is hardly present in current ­policies. The New Build Heat Standard – which bans the installation of

fossil fuel gas boilers in newly constructed ­houses in Scotland – recommends heat ­networks or heat pumps, but makes only one ­mention of hydrogen boilers “if the ­market can ­deliver them.”

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However, we might see some hydrogen in our households before the end of the decade if proposals to mix hydrogen into mains gas go ahead. Up to 20% ­hydrogen mixed with natural gas in our homes poses no greater safety risk than purely natural gas and unlike 100% hydrogen supply, a 20% blend does not require any new appliances or boilers.

While the UK Government is yet to make a definitive decision on hydrogen mixing, mains gas could be blended as early as 2026. Holyrood says it is pushing for hydrogen blending by 2030.

Hydrogen producers are a big fan of hydrogen blending, which could provide a stop-gap before dedicated hydrogen pipelines are built. On the consumer side, it is difficult to tell whether this is a smart move; some have called blending an “expensive distraction”, predicting up to 20% household gas bills for only 7% emissions reductions.

Furthermore, some industrial facilities may be unable to function with a 20% ­hydrogen mix, forcing them to remove the hydrogen from their mains gas ­supply.

Hydrogen for transport: Still in the race

WHILE electric vehicles (EVs) ­have completely dominated the market for personal transport, long-haul transport is more difficult to electrify because of the short range of EVs. While technology is advancing at pace for electric heavy-duty vehicles, hydrogen is currently an equally viable solution.

In Aberdeen, a fleet of public vehicles including buses and HGVs have been running on hydrogen for years. Attracted by the hydrogen infrastructure in the area, utilities company SSE trialled their new hydrogen vans in Aberdeenshire last year. In Northamptonshire, Hydrogen Vehicle Services have built an HGV using a hydrogen fuel cell; a mechanism which uses hydrogen to fuel an electrochemical reaction, rather than burning it.

Transport companies across the UK and Ireland are signing up to trial these fuel-cell HGVs.

Hydrogen fuel cells are also a potential key for decarbonising aviation. ZeroAvia is just one of the companies leading the way in the UK with their hydrogen engine system which can be fitted into existing kerosene-powered aircraft.

While larger aircraft have not yet been developed, small planes suitable for short domestic flights – especially ­inter-island journeys – are set to hit the market by 2025. Scottish-headquartered Ecojet has committed to buying 70 engines from ZeroAvia, and Scottish Power has made a partnership with the company to ­provide hydrogen supply at strategic ­airports in Scotland.

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However, it’s difficult for hydrogen fuel cells to compete with the ­immediate convenience of sustainable aviation ­fuels (SAFs) – these biofuels can be used ­instead of kerosene with little to no ­engine ­modifications. The first waste-to-jet fuel plant in the UK has secured ­planning permission, and Holyrood is considering emissions trading regulations which would provide a financial incentive for airlines to use SAFs over kerosene.

Hydrogen at sea: Part of the equation

IN operations at sea – whether in offshore gas turbines or international shipping – it seems that some kind of hydrogen-derived fuel is better than pure ­hydrogen. NZTC has been researching the application of alternative fuels in both of these sectors.

The production emissions of the ­British North Sea offshore industries was a ­colossal 14.3MTCO2e in 2021. For ­context, all of Scotland’s domestic emissions amount to 40.6MTCO2e.

A large proportion of these emissions come from gas-powered turbines.

“Hydrogen can be used as an ­alternative fuel [in offshore gas ­turbines], but it’s not the right fuel for the ­majority of offshore applications,” says Gee, who ­manages NZTC’s research into ­alternative fuels for offshore gas ­turbines. In the North Sea’s gas turbines, burning hydrogen ­eliminates CO2 emissions but sends nitrous and sulphur oxide ­emissions through the roof.

Shipping is another huge emitter in Scotland. While ammonia (also derived from hydrogen) was proposed as an ­alternative for diesel-powered vessels, NZTC has found that it is fairly toxic to the waters around it. Not only that, but the storage of ammonia around busy quaysides raises significant safety risks.

However, in both of these contexts, e-methanols (fuels made using hydrogen and captured CO2), as well as biofuels, are now being tested with more promising results.

“The key lesson we’ve learned is there is no silver bullet,” says Gee. “We still need large-scale hydrogen, but we’re also likely to change it into a different ­molecule to use it effectively, dependant on need, and supplement that with other alternative fuels.”

One solution among many

HYDROGEN will not be able to fully replace fossil fuels – but that doesn’t ­discredit the case for hydrogen as an important part of a net-zero society. In a system structured around one fuel, it would be an incredible stroke of luck to discover another fuel which slotted ­perfectly into the same system.

As it stands, there are dozens of ­potential uses for Scottish hydrogen, but hydrogen and its derivatives may be largely ­invisible to the average Scot. It’s ­unlikely to be heating our homes or ­fuelling our cars, but it could be ­transporting the commodities we buy in the supermarket, powering the factories outside our cities, and heating the stills that make our whisky. It might be powering a flight from Glasgow to Lerwick, or mixed into the gas we cook our dinner on.

But in many of these sectors, the debates around the best energy sources are ongoing. With so much of Scotland’s industrial strategy leaning on hydrogen production, advocates of hydrogen will be under pressure to prove its value alongside biofuels or electricity.