Battery electric vehicles dominate the UK’s efforts to clean up road transport emissions. But hydrogen fuel cells may have an edge for heavier vehicles.

Battery electric vehicles (BEVs) have a clear lead in decarbonising global road transport. This is backed by years of government support, innovation that has reduced costs, efficiency and substantial infrastructure buildout.

In contrast, hydrogen fuel cells adoption is still in its early stages.

However, hydrogen fuel cell vehicles (HFCVs) may be a better choice than BEVs for heavier road transport. The UK could unlock this potential – with the right policy tweaks.

Transportation in the UK accounted for 109 million tonnes of CO2e in 2021, around one quarter of the total. Cutting these emissions will have an impact on the UK’s net zero goals, but also on local air quality. HGVs accounted for 20% of transport emissions.

The efficiency problem

Thus far, most of the focus has been on BEVs. These have an advantage over HFCVs in terms of energy efficiency.

To fuel a BEV simply requires the production, transmission and distribution of electricity.

This is opposed to the hydrogen delivery chain, which requires converting power into hydrogen, transporting it, compressing or liquefying it, storing it and then converting it back into electricity in the car.

Electrolysers convert renewable power into hydrogen at roughly 80% efficiency, Matthew Kubesh, a research engineer at the Texas-based Southwest Research Institute, explained to E-FWD. But after transport, storage and conversion back into electricity, only around 30% of the original energy remains, he said.

Samuel Furfari, a professor of energy geopolitics at the Free University of Brussels, has been a vocal critic of hydrogen’srole in the energy transition. He puts the efficiency of HFCVs at 28%.

Furfari is a former senior energy official at the European Commission. He oversaw fuel cell demonstration projects, which had disappointing results in efficiency and cost. HFCVs will always need subsidies, he has said, unlike BEVs. In some markets, these vehicles have moved beyond that need.

Low energy efficiency drives up HFCV costs. BEVs use cheaper technologies with fewer parts, resulting in lower initial and maintenance costs.

BEVs benefit from an established market, with widespread adoption and infrastructure deployed nationwide in many countries. Today, HFCVs are only practical in a few regions, like major Chinese and Japanese cities or California. In the UK, there are only six hydrogen filling stations open to the public, compared with over 35,000 charging locations.

Heavy-duty edge

Still, BEVs face challenges in the heavier transportation space.

Amaury Laporte, vice president of communications at the Washington-based non-profit Environmental and Energy Study Institute, was once enthusiastic about hydrogen fuel cells in transport. But the improvement in electric batteries over the past decade has made fuel cells less competitive, particularly given the inefficiency issue.

“My enthusiasm has definitely been tempered somewhat, but I still think fuel cells and hydrogen still have some interesting applications in transport,” he told E-FWD.

The applications include trucks, heavy vehicles, shipping and potentially trains.

According to Laporte, the more “power-hungry” the mode of transport, the more promise there is in hydrogen fuel cells. According to Kubesh, larger vehicles need bigger, heavier batteries, which can be a challenge for BEVs.

“Certainly, for light-duty cars, electric batteries may be the simpler choice,” Keith Wipke, fuel cell and hydrogen technologies programme manager at the Colorado-based National Renewable Energy Laboratory, told E-FWD.

“They’re already out in the marketplace and people like them and are able to charge them at home and use a network of charging points for longer trips.”

He says the energy loss in converting electricity into hydrogen and back is well-recognised.

“It’s not a secret, it’s not something the hydrogen community is trying to hide in any way,” he said. “Because of the multiple steps, it is less efficient than a battery storage option for small amounts of energy. But the case for hydrogen in heavy-duty transport is really where batteries can have challenges.”

Fuelling faster

Productivity is key. HFCVs can be refuelled much faster than BEVs. The National Renewable Energy Laboratory (NREL) filled a simulated truck with over 80 kg of hydrogen – the energy equivalent of 80 gallons of gasoline, a full load for some medium-to-heavy duty trucks – in under 10 minutes. With a battery electric truck, the wait is much longer.

“Nobody wants to pay a driver to stand around for a couple hours, or even an hour,” Wipke said.

BEV charging times have improved significantly and ongoing research aims to make them shorter. But the physics offaster charging rates presents challenges. Energy losses increase exponentially with higher current.

“The energy lost to resistance in wires goes up by the square of the current,” Wipke noted. “So if you go from 100 amps to 1,000 amps, you’re not just going up by a factor of 10 in energy losses, but by a factor of 100.”

HFCVs can travel longer distances between refuels. “For heavy-duty transport, it’s very difficult to get enough energy into a truck to allow it to drive five or six hundred miles with today’s electric charging technology. It’s been demonstrated that you can do this with hydrogen,” he continued.

Kubesh added that beyond trucking, hydrogen fuel cells may also be practical for buses and fleet systems.

Off grid fuelling

Buses are on the road longer than personal vehicles, making quick refuelling more critical. They follow set routes and return to a central hub, simplifying refuelling logistics. Hydrogen could also serve as a good transport option in remote locations that are harder to electrify, like mining and construction.

Indeed, Anglo American launched a test for a hydrogen-fuelled truck in South Africa in 2022.

“It’s hard to justify or even implement the high power infrastructure needed for megawatt charging in these areas,” Kubesh explained. “Hydrogen can be brought in by truck same as any other liquid fuel or even a mobile refuelling station. This allows the capability to decarbonise a very difficult sector of industry.”

Productivity is central to the philosophy of US retail giant Amazon. This helps explain why Amazon was an early adopterof hydrogen fuel cells for machinery. Amazon uses 15,000 hydrogen fuel cell forklifts in its warehouses and plans to expand to 20,000 by 2025.

Innovation

The case for hydrogen fuel cells in transport may grow with technological advances. Laporte noted that fuel cell technology has not benefited from the same investment as battery technology over the past decade.

A key focus of research has been improving efficiency and durability, Wipke said. Overcoming the efficiency issue is crucial as the fuel cost is much more significant in trucks than in personal vehicles, owing to their longer time on the road.

According to Kubesh, innovation could significantly reduce expensive catalysts like platinum and rhodium in fuel cells and electrolysers. Cutting platinum in fuel cells to 0.06 grams per square centimetre, a fivefold reduction, would align its cost with modern diesel exhaust systems.

Meanwhile, researchers are focused on increasing the durability of fuel cells for heavy duty to match internal combustion engines.

Under pressure

There’s potential for innovations in hydrogen production. Hydrogen electrolysis was first demonstrated over 200 years ago but never deployed on a large scale, leaving opportunities for improvement.

One avenue of research is high-pressure electrolysis, which could improve efficiency by incorporating hydrogen compression in the production process.

Another focus is high-temperature proton exchange membranes (PEM), used in electrolysers and fuel cells. Kubesh explained the higher temperatures mean less catalytic energy is needed, allowing the use of newer and cheaper catalysts like nickel and platinum alloys.

It also unlocks the potential for higher fuel cell conversion efficiency. But the challenge is ensuring comparable performance and durability to today’s low-temperature fuel cell membranes.

Many high-temperature membranes are free of polyfluoroalkyl substances, otherwise known as “forever chemicals.” This is important as many governments are considering strict limits or bans on these chemicals.

Low bar

So far, hydrogen fuel cell road transport deployment in the UK is minimal. Despite multiple funding initiatives forresearch and development (R&D) and deployment, there are no specific targets or strategies outlining the technology’s role.

The UK has a strong hydrogen funding landscape and R&D and manufacturing base, Jon Regnart-Russell, senior policy advisor at Hydrogen UK, told E-FWD. This has supported novel start-ups like Intelligent Energy, with high-performance fuel cells, and Hydrogen Vehicle Systems and First Hydrogen, which developed fuel cell-powered vehicles.

Regnart-Russell said that to accelerate fuel cell vehicle adoption, there should be a co-ordinated government approach. It requires a mandate to establish a hydrogen refuelling infrastructure for greater investment certainty.

Four different government departments handle hydrogen planning and funding. The extent to which they see a future for hydrogen in road transport varies.

“This sends mixed signals to industry, which jeopardises future investment decisions in refuelling stations and vehicles,” Regnart-Russell said. He called for these departments to develop a joint strategy for hydrogen use in transport. This would provide a consistent message to provide investor confidence.

Supply chain

Funding should be co-ordinated so UK hydrogen deployment projects incentivise a UK supply chain. This would help UK technology flourish, he said, rather than relying on imports.

And the UK could consider establishing something similar to the H2Accelerate initiative in the EU. This provides funding across the hydrogen sector, from supplier, refuelling station operator and vehicle manufacturers, he said. This reduces the risk of investment across the entire system.

Regnart-Russell commended the UK government for designating Tees Valley as a hydrogen mobility hub. This should be expanded, he continued.

Industrial areas like Tees Valley, with hydrogen demand and low-carbon production, can maximise the impact of public spending. But more support is needed for a hydrogen transport hub network. “Otherwise you’re just left with an island that is not connected with anything.”

Regnart-Russell called for a scheme similar to the Zero Emission Bus Regional Areas (ZEBRA) scheme. Under this, local authorities could bid for funding to establish hydrogen vehicles and refuelling networks.

Networked solution

To avoid the “chicken-and-egg” challenge to new technology adoption, a government mandate should establish a basic hydrogen refuelling network. In a pre-election manifesto, Hydrogen UK called for the new government to create a heavy goods vehicle and bus infrastructure strategy with a target of 50 hydrogen refuelling stations by 2035.

Ideally, this should align with the EU’s Alternative Fuels Infrastructure regulation. This requires a hydrogen refuelling station every 200 km along Europe’s core transport networks, with additional stations in urban areas.

Regnart-Russell said that adopting a similar requirement would “provide baseline confidence for investment to happen”. It would also facilitate future trade in hydrogen fuel cell vehicles with the rest of Europe.

The UK was due to publish its Low Carbon Fuels Strategy in May, but was delayed. Clarity on this would do much to advance how the sector took steps to prepare for the future.

Companies working in the sector have often found it hard going. Tevva Motors, for instance, was working on a hydrogen truck prototype but was forced to call in administrators this year.

There are plans to expand hydrogen provision for trucking in the UK. Protium is backing the HyHAUL project, providing HGVs and fuelling stations along the M4. Crucially, the government provided £30 million to support the plan.

Articulated plans

Despite some of the early excitement around hydrogen as a fuel source for passenger vehicles, this looks unlikely to deliver. But this doesn’t mean there is no future for hydrogen in transportation.

The advantages that HFCVs can offer makes them a contender in those areas that batteries will struggle to reach. Just because batteries have made progress, does not mean they will be the answer for every problem.

The UK has an opportunity to mark out a way forward for hydrogen as a road fuel. But this will require concerted action by the government to articulate plans and set out support mechanisms.

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