Transport focus: hydrogen vehicles - the future?

In this article, we consider the application of hydrogen transport technologies, the status of UK policy and government support for hydrogen fuel and in particular its application in the road to net-zero, and the benefits and drawbacks of the use of hydrogen to power our vehicles.

In addition to the application of hydrogen in heat, power and industry (for further information, please see our article on the use of hydrogen in the UK’s energy mix, hydrogen transport technologies are increasingly being seen as a viable energy source to meet our net-zero transport needs of the future.

The government has set out its intention for hydrogen to form a major part of the UK’s journey towards net-zero by 2050 in the Energy White Paper published on 14^th December 2020. We are currently awaiting the release of the dedicated Hydrogen Strategy, which should provide some much-needed detail on the framework for increased investment in hydrogen technology and infrastructure. The government has set a target of 5GW of low carbon hydrogen production capacity by 2030. This motion will be supported through a £240m Net Zero Hydrogen Fund and the publishing of the required hydrogen business models and a revenue mechanism to allow the fund to bring in private sector investment, which the government estimates could be well over £4bn by 2030. The government has also announced it will ensure that existing renewables support mechanisms, such as the Renewable Transport Fuel Obligation, will be able to provide an appropriate level of support.

How can hydrogen be used to power vehicles?

Hydrogen vehicles use fuel cells, which produce electrochemical reactions between hydrogen fuel and oxygen in the air. During the reaction, the hydrogen and oxygen combine to produce electrical energy. The electrical energy produced, powers the vehicle and the only by-product is water vapour.

Where batteries are unviable (such as in longer-range applications), hydrogen offers a rapid refuelling solution. In particular, hydrogen transport technologies are increasingly seen as being well suited to commercial fleets as they do not have long periods of downtime in their duty cycle.

Hydrogen vehicles are also extremely efficient. In a typical hydrogen car, nine litres of water can translate to a range of around 100km.

Hydrogen vehicles: The upsides

Refuelling and range anxiety

Fuel cell operated hydrogen vehicles are able to be refuelled much like traditional petrol and diesel vehicles, with hydrogen being pumped into on-board fuel tanks. Refuelling a HGV is estimated to be achieved in 3 to 5 minutes. Once a hydrogen vehicle is fuelled, it can travel just as far as a traditional vehicle on a single tank.

Fuelling speed and range anxiety are the two major drawbacks of electric road vehicles, the main competitor to hydrogen. Charging these vehicles can still take many hours if you do not have access to a fast charge point and, whilst significant developments are being made in battery technology, the worst performing hydrogen vehicles are still able to travel more than 50% further than leading electric vehicles on a single tank versus a single charge.

Weight

In addition to improved fuelling speed and range, hydrogen fuel tanks are significantly lighter than the lithium-ion batteries that fuel the majority of the current leading battery electric vehicles. At this stage, using battery-derived power for large vehicles travelling long distances has proved difficult, as the sheer size of the batteries required adds considerable weight to the vehicle, which would serve to exacerbate the associated range anxiety and charging issues highlighted above. Therefore, the current direction of commercial and government efforts focusses on the use of hydrogen in busses, trains and HGVs.

Hydrogen vehicles: The drawbacks

As reported in their press release, recent testing conducted by leading HGV manufacturer Scania has revealed two major flaws with hydrogen vehicles:

• The first is that it takes 3 times more renewables energy to power a hydrogen HGV when compared with an electric battery HGV. This is because a large amount of energy is currently lost in the production and distribution of hydrogen fuel, as well as in the conversion back to electricity which takes place on board.

• The second is that the inner workings of a hydrogen vehicle are significantly more complex than electric vehicles, which means that currently the costs of maintenance are much higher.

Other downsides to hydrogen vehicles which have been identified are:

• Refuelling stations – currently, there are very few hydrogen fuelling stations in operation. Whilst the government has promised to invest heavily in hydrogen fuelling infrastructure, this is a major barrier to market when you consider the reported vast expense associated with constructing them

• Flammability – despite claims of crash safety from leading manufacturers and the fact that petrol is also highly combustible, it appears that the Hindenburg factor is still causing anxiety amongst potential consumers

• Vehicle costs – prices for hydrogen cars for example start at around £50,000. Electric car prices have dropped dramatically over recent years and start at around £17,000 and (excluding luxury models) have a UK average price of around £27,000. In addition to initial vehicle costs, the cost of running a hydrogen car is also very high. Costs of refuelling reportedly ranges between £40-£90, which is vastly more expensive than an electric battery powered alternative (although on par with petrol and diesel), even when taking the frequency of refuelling into account

• Uncertain regulation: the UK regulatory framework does not contemplate the large-scale production of hydrogen or its use as a substitute for other conventional fuels. This regulatory uncertainty is a barrier to investment. In particular, the right safety management regulations will need to be implemented to manage hydrogen. Standards and rules would provide stakeholders with the information needed to safely build, maintain and operate facilities.

Not all hydrogen production is truly net-zero: blue, grey and green hydrogen

• Green hydrogen is produced using an electrolysis method to split hydrogen from water. The electrolysis process is powered by a renewable energy source, such as solar, wind or hydroelectricity. Green hydrogen is zero carbon

• Blue hydrogen is produced using a steam methane reforming method (powered by non-renewable energy), where high-temperature steam reacts with methane in the presence of a catalyst to produce hydrogen, carbon monoxide and carbon dioxide. As carbon is produced as a bi-product of this process, blue hydrogen production utilises carbon capture and storage (CCUS) to capture the waste carbon and store it as securely as possible underground. Blue hydrogen is low-carbon; it is not zero carbon.

• Grey hydrogen is similar to blue hydrogen but without the use of CCUS, thus emitting carbon. Grey hydrogen is not zero or low carbon.

Biomethane: A new competitor?

Whilst not mentioned in the Energy White Paper, the Anaerobic Digestion and Bioresources Association (ADBA) have identified that biomethane (a gas produced from the anaerobic digestion of organic matter) could be a viable alternative to hydrogen powered HGVs for example.

Waitrose, John Lewis, Argos and Brit European HGVs for example are already using biomethane fuel, which is distributed through existing gas pipelines and then compressed into fuel at fuelling stations. Reportedly, the biomethane industry can generate 76TWh of biomethane annually, equating to 97% of HGV demand. Biomethane is reportedly 35-40% cheaper than diesel and emits 70% less CO2 on a well-to-wheel basis, which would offer fleet operators dramatic reductions in emissions. Therefore, it appears that biomethane could offer a viable solution, which is available today, rather than wait for hydrogen vehicles that currently require far more infrastructure development to reach the market.

Conclusion

Hydrogen is a viable transport fuel and the use of green hydrogen in our cars, busses, HGVs and trains will help the government along the road to meeting its net-zero targets. Current government policy and support is to be expanded upon in the forthcoming Hydrogen Strategy, expected to be published later this year. In the meantime, development work continues apace with many public transport operators supporting research and participating in pilot projects. A major bus manufacturer is preparing for the production of up to 4,000 hydrogen powered buses by 2024.

Hydrogen vehicles can provide a rapid refuelling and longer-range alternative to other low carbon technologies such as battery electric vehicles, although hydrogen will need to address the current inefficiencies and the loss of energy in hydrogen production and distribution, high capital outlays and costs for the purchase and ongoing maintenance of hydrogen vehicles, and the lack of refuelling infrastructure and latent safety concerns before hydrogen can be seen as a potential market disrupter to the transport sector.