An SMR or ATR plant provides a large centralised hydrogen source, which surrounding industries can use to reduce their emissions. Some industrial clusters, such as Merseyside and Humberside, are located close to depleted gas fields, giving the SMR or ATR plant a potential carbon sink. Many industries (such as the steel industry) are already experimenting with hydrogen-fired alternatives to their normal equipment, and umbrella projects have sprung up to co-ordinate these approaches across each cluster. The Government has supported this through various low-carbon hydrogen and carbon capture funding pots, with recipients including The Acorn Project in Aberdeenshire (supporting the Grangemouth cluster) and HyNet in North West England (Merseyside). The race to be the first net zero cluster is on.
Moving away from industry, the UK has an extensive and relatively modern natural gas network. This supplies around 84% of the nation’s homes for heating, in addition to a large number of gas engines and gas turbines across the country. Heat is an energy sector that has historically seen little decarbonisation progress in the UK, and so decarbonising this common network, by replacing some (or all) of this natural gas with green or low-carbon hydrogen, is an obvious step. This is both theoretically straightforward and needs very little new technology, and numerous projects are testing the gas grid’s capacity for change. As an example, HyDeploy started undertaking live testing at Keele University campus in 2019, having obtained the first exemption from the HSE to inject hydrogen into the grid – up to 20% of total gas grid volume. Meanwhile, H21 is a suite of projects exploring the conversion of the gas grid to 100% hydrogen. If proven safe and possible, and backed up with suitable subsidies (similar to biomethane injection), hydrogen injection could go a long way towards decarbonising the UK heat sector. Hydrogen-ready boilers and gas turbines are already coming onto the market, so this demand is unlikely to disappear in the short and medium terms.
A further use for hydrogen is in the mobility sector, another hard-to-decarbonise area that has seen little movement in recent years. Road transport in the UK accounted for approximately 21% of the UK’s total greenhouse gas emissions in 2017, with the absolute amount actually increasing by 6% since 1990. While early attempts at hydrogen mobility were overshadowed by airship-shaped disasters, recent efforts have been more successful, and a large variety of hydrogen vehicles are in development or already available.
Is hydrogen a competitive technology? It depends on what you want to transport where. Electric vehicles are firm favourites at passenger vehicle level, partly due to the range of consumer choice available and the more convenient recharging infrastructure. The key advantages of hydrogen (shorter refuelling times and smaller weight and space penalties with increasing range) are not as important here as its current disadvantages (cost and rare refuelling stations). However, the advantages are far more important for heavier vehicles like heavy goods vehicles and buses. Buses and some heavy goods vehicle fleets (for example, those servicing Energy from Waste plants) have predictable routes and a return-to-depot use pattern, making refuelling infrastructure relatively simple to build. London and Aberdeen already have demonstration fleets of hydrogen buses, with Liverpool and other cities following suit over the coming years.
Another option, where hydrogen can work alongside electric alternatives, is the train system. Electrification of lines is expensive, and while this is commercially viable for the busiest lines, it does not make as much sense for branch lines and less heavily-used parts of the network. For the most part these trains currently run on diesel, but they can be retrofitted (or built from new) to run on hydrogen. One example of this retrofitting approach is the Breeze train, developed by Alstom at their site in Widnes, which builds on their experience with the hydrogen-powered iLint in Europe. The first UK Breeze fleet is expected to be in operation by 2024 and, if successful, these trains could be rolled out across the country. Like buses, trains have set routes and predictable usage patterns, and refuelling stations would therefore be simple to link with hydrogen supplies.
Curiosity and Opportunity
In summary, a UK hydrogen economy is far from a far-off plan. Pre-existing strengths in renewables and oil and gas can support a strong domestic hydrogen supply, while net zero emissions targets will drive demand. This balance puts the UK in an almost unique position among the hydrogen frontrunners, as most focus only on one side of the equation. Australia will produce for export as its own demand is small, for example; Germany and Japan are facing the exact opposite problem and will need to import. Both approaches mean each country must trust that another will be able to supply it what it needs. Not so the UK: home-grown hydrogen production and domestic consumption could be linked, to create a self-sufficient and self-sustaining hydrogen economy.
This will be a delicate balancing act, as supply and demand grow from localised clusters to a mature network. Small change is already underway, but the time of pilot projects and demonstration scale is coming to an end. Pace needs to increase, and concrete developments begun, if the UK wants to meet its net zero obligations and become a hydrogen world leader. Some may wonder how reasonable such a big change may be in such a short time and whether there is appetite for this at the top. However, the Government seems convinced that hydrogen will have a key part to play in the future low carbon world – and refuses to let the UK be out of the limelight.