Fuelling the hydrogen transition

Hayley Everett

How the rapidly growing global demand for hydrogen refuelling infrastructure is supporting the move to net zero

When produced via renewable energy sources, hydrogen fuel can be considered a good candidate to contribute to the decarbonisation of the mobility sector. The main advantages of fuel cell electric vehicles include the zero emission of CO₂ and pollutants, as well as the higher efficiency of fuel cells compared with internal combustion engines (ICEs).

Hydrogen can be used in both ICE and fuel cell vehicles directly as an energy source, where the fuel cell uses the chemical energy of hydrogen to cleanly and efficiently produce electricity. There are various mobility applications where hydrogen fuel makes sense, such as fuel cell-powered industrial trucks that operate indoors, trains where electrification is not possible, potential energy providers for aircraft, on-board power supply for shipping vessels, public transport buses, and fuel cell hydrogen trucks in the heavy-duty vehicle segment.

While hydrogen fuel is not a new concept, to advance the adoption of hydrogen-fuelled vehicles attention is now shifting towards developing the necessary refuelling infrastructure to support this transition.

How does hydrogen refuelling work?

Hydrogen fuel cell vehicles can be refuelled quickly and efficiently at a hydrogen refuelling station, in a process comparable to traditional refuelling methods such as petrol or diesel. One company leading the development of such refuelling stations is UK-based Haskel, which has been innovating compression, storage and dispensing technologies for hydrogen for decades. In recent years, the firm has focused on developing standardised hydrogen refuelling stations, of which it shipped 12 last year.

“Fuelling these vehicles in a safe manner is our foremost priority, as is how we can do this in line with the transition to net zero,” says Jake Martin, International Hydrogen Business Development Leader at Haskel. “We shipped 12 of our big hydrogen refuelling stations last year, which are very complex systems that allow you to fill a vehicle very similar to the experience you would expect at a petrol station; a car can be filled in two to three minutes, while a truck can be filled in nine to 10 minutes.”

Configured for optimum performance based on the hydrogen inlet pressure, the company’s refuelling stations work by compressing hydrogen in various stages using its compression technology to increase the pressure and reduce the volume of the gas. This enables a more efficient flow of gas when dispensing. Then, a heat exchanger removes the excess heat from the gas that was generated during compression before the hydrogen is cooled to sub-zero temperatures. This optimises the fuelling experience, while vent lines are situated throughout the system to ensure the hydrogen can be removed safely during operation. Finally, the dispensing process regulates the flow of the gas to enable the direct dispensing of hydrogen through a nozzle into the vehicle at a controlled pressure and rate.

Hesitancy around hydrogen

Despite all the benefits that hydrogen promises, there is some negativity surrounding its use as a fuel for transportation, as Martin explains: “Historically, in this industry in particular, there has been quite a negative message around hydrogen, especially from older generations. This needs to change, and I think this transition is starting to happen. Engineers in particular see hydrogen as a molecule that is based on sound gas principles, like Boyle’s Law and the Joule-Thomson effect. The safety aspect is very important, as is the realisation that we’ve all already been sat on tanks of combustible fuel for years in the form of petrol and diesel vehicles, and hydrogen refuelling stations are actually much safer in terms of the refuelling process.”

The hydrogen industry is also subject to strict safety-driven standards and regulations in regards to temperature, refuelling protocols, and actual fill times. As part of the British Compressed Gas Association (BCGA), Haskel is supporting the further development of these standards within the UK to promote safety in the use, storage, transportation and handling of hydrogen.

Growing momentum

Although the UK is lagging significantly behind the progress made by more renewable energy-positive countries like Australia and New Zealand - where Haskel has shipped a number of its refuelling stations already - in transitioning to hydrogen fuel, momentum in the industry is slowly gathering pace.

“We have all the expertise in the UK to do this,” Martin says. “But what we need to do is empower businesses to want to make hydrogen a solution and sit down with manufacturers and industry to show them how hydrogen can support our current infrastructure. Hydrogen is already beginning to be transitioned into the grid, which will make it even more palatable to invest in.”

Looking ahead, what factors might affect the ongoing transition to hydrogen fuel within the transportation sector? While we might not see hydrogen cars on our driveways anytime soon, Martin believes the logistics sector will be where hydrogen really makes an impact over the next decade.

“In particular, I see the transition taking place for vehicles moving products around on a back-to-base basis, so anything that starts from one location and returns back to the same place,” he explains. “These could be measurable trips by trains, trucks, planes and so on, and aviation will certainly be a big focus. Fleet operators, such as large supermarket chains, that are delivering a large amount of product throughout the UK will likely transition to hydrogen, and Haskel is working with several of these companies now.

“One of the most important aspects of this transition will be educating people and businesses on how the refuelling stations work and can be integrated into their existing infrastructure and logistics strategies. Hydrogen is not the only answer, but it is a solution that will play a vital role in the journey to net-zero.”