Hydrogen cars - a lot of hot air?
We don’t hear much about the hydrogen revolution these days. Is fuel-cell technology a pipe dream or a viable solution to transport and energy needs?
The silence is palpable, the progress smooth, as the big Japanese car winds its way along narrow lanes through the Sussex countryside. It emits nothing but heat and water.
But this is no conventional plug-in battery-electric vehicle. The car is called Mirai, the Japanese word for “the future”, and it is one of the world’s first hydrogen fuel-cell electric vehicles (FCEVs) to go on sale, as opposed to being leased or loaned as part of automotive development or technology demonstration programmes.
The Toyota Mirai’s sleek exterior conceals technological marvels, which bullish futurists insist could catapult the transport sector into a nirvana that is green, silent and abundant. “We consider FCEVs as the ultimate eco-car, with the same usability as petrol vehicles in terms of cruising range and refuelling time,” says Isotta Cerri, Toyota’s manager of advanced materials research.
The benefits of hydrogen are as plentiful as the gas is omnipresent. Hydrogen is the lightest and most abundant element in the universe. And, when compressed to 700bar, its energy density is five times higher than current batteries by weight. So, intuitively, it seems like a good idea to use the energy carrier as a fuel.
Three years on from the Mirai’s launch, however, FCEVs remain elusive on the roads. By the end of 2017, merely 5,000 Mirais had been sold worldwide, and the car’s rivals – there are only two so far, the Kia ix32 Fuel Cell and the Honda Clarity FCV – are not doing any better.
Which begs the question: will there ever be a market for fuel-cell electric vehicles?
There appears to be a growing consensus that FCEVs have lost the race against battery-electric vehicles (BEVs). This argument has been spearheaded by Tesla’s chief executive Elon Musk, who has described FCEVs as “mind-bogglingly dumb”.
By contrast to the slow sales of FCEVs, BEVs are fast gaining mainstream acceptance. Sales have been buoyed by support from governments, plummeting prices, rapidly reduced charging times, and improved battery technology resulting in fast-increasing range.
BEV pioneer Nissan has already sold more than 300,000 Leaf cars since the model’s launch in 2010 and sales continue to rise, with the latest version delivering double the range of the original. Tesla’s latest Roadster BEV, meanwhile, comes with a range of 1,000km per charge. That is double the Mirai’s range per tank, and indeed well ahead of the range of conventional petrol and diesel cars.
Even Daimler chairman Dieter Zetsche, a long-time advocate of hydrogen, appears to have changed his mind. Daimler is scaling back its ambitions for FCEVs in favour of BEVs, in response to declining battery costs.
In spite of this, Toyota’s commitment to FCEVs remains strong. The carmaker is sticking to a target of “30,000 FCEVs a year on a global basis by around 2020,” according to Cerri, who points out that the vehicles are “already a preferred solution for specific businesses, such as taxis, for example in Paris, London and Hamburg, and for city buses. We also see hydrogen being adopted for trucks, trains and even boats and planes”.
On the face of it, rapid refuelling is the Mirai’s main advantage over battery-powered electric vehicles. It beats even fast BEV charging times by a country mile.
But for now, in rural Sussex – which with its quaint villages and green, rolling hills is not exactly a picture of modernity – this promise of a quick refuel offers little comfort, because there are no refuelling stations here. This is true for most of Britain, of course. There are only about a dozen commercial hydrogen fuelling stations dotted around the UK.
So far there are only about 12 commercial hydrogen refuelling stations in the UK – this one is in the US (Credit: Shutterstock)
The nearest one is in Cobham, 50km away, where last year Shell became the first mainstream fuel company to open a hydrogen station. The hydrogen part of the forecourt is a bulky affair, with an electrolyser that produces the gas on-site and a vast tank, constructed to the side of the petrol and diesel pumps.
Filling up is straightforward, though fiddly when compared with diesel or petrol because the nozzle must be plugged in and sealed to prevent the hydrogen gas from escaping. Payments are easy, however, as they are made at the pump with a dedicated fuel card, so this feels like a significant step towards normalising FCEVs.
“The roll-out of refuelling stations in the UK is significant,” says Graham Cooley, chief executive of ITM Power, which installed and operates the Cobham facility. “We make the hydrogen on-site, so the cost per mile in the Mirai is comparable to petrol.”
The consumer experience at the Cobham forecourt is markedly different from that at the Hatton Cross refuelling station, which is more representative of what the customer typically finds. A recent visit revealed a fenced-in, grey complex, tucked away on a near-deserted industrial site near Heathrow, where the only other car present was a Honda Clarity FCV and a TV crew that was there to film it.
In spite of the emergence of more mainstream stations, such dour, industrial refuelling points are set to remain the norm, largely because several more are set to be made available for private drivers on sites owned by commercial vehicle operators, which are emerging as major customers for hydrogen.
“The diversity and scope of hydrogen vehicles are increasing fast,” says Cooley, pointing out that last year Alstom began testing the world’s first fuel-cell passenger train, that there are 18 companies making hydrogen buses around the world, and that fuel-cell forklift trucks are increasingly common in warehouses. “Commercial vehicles, such as vans, buses and forklift trucks, tend to come back to the same place each day. This makes the refuelling stations financeable,” he says.
Moreover, private drivers stand to gain from the growth in numbers of commercial FCEVs, he insists: “All our bus station installations have additional dispensers facing the road, for cars,” he says. “We mustn’t get fixated with the refuelling of passenger cars when there are all these other things happening.”
But we have heard it all before, have we not: lofty visions of a hydrogen-fuelled future that somehow never arrives? “Hydrogen is a technology that’s always three to five years away,” Tesla’s chief technical officer J B Straubel quipped in a speech last year. That view has been echoed, perhaps surprisingly, by Arno Evers, who in 1995 founded the exhibit on hydrogen and fuel cells at the Hanover Fair.
“There is no market,” Evers insists. “There’s never been a market. I’ve been doing this for 23 years, I’ve been to 110 conferences, and I’ve heard the same arguments, the same philosophies, time and time again. It’s not about the technical qualities. The technology has not moved forward, not at all – how could it?”
Cooley disagrees. “The world is different now,” he says. “The difference is, we now have the cars.”
Ian Mutton, chairman of Hydrogen Mobility Australia, is also optimistic about the future of FCEVs. “While battery-electric vehicles represent one technology option, fuel-cell vehicles, similarly powered by electricity, present another genuine alternative for delivering reduced transport emissions,” he says.
Indeed, the Mirai’s modest market entry belies the vast scale of Toyota’s hydrogen programme. The company has invested heavily in the technology since it began its development programme in the 1990s.
“In the beginning, Toyota thoroughly analysed and evaluated all the possible fuel-cell technologies,” says Cerri. “The result of this evaluation was a focus on H2 PEM FC (polymeric electrolyte fuel cell) as the optimal solution.”
The company’s solution consists of a fuel-cell stack made up of several hundred individual cells, which mix compressed hydrogen (700bar) with oxygen, converting it into electricity by means of a chemical reaction. The electricity is fed into a battery, which also takes power from regenerative braking, making the process even more efficient. The electric motor draws power from the battery.
“The Mirai builds on our petrol-electric hybrid architecture,” says Cerri.
So the technology is in place, and so is the backing by powerful governments and companies around the world. Japan is particularly keen, aiming to install 160 refuelling stations and to have 40,000 fuel-cell vehicles on the roads by early 2021. Last December a consortium of 11 Japanese companies, including Toyota and Nissan, was set up to take part in this effort. The European Union and the US are also supporting hydrogen developments, with generous investments, as part of a drive to cut harmful emissions.
The world has changed in other ways too. “The driving force for hydrogen today is about air quality,” says Cooley, referring to growing efforts by local governments around the world to rid their cities of petrol and diesel vehicles. “It’s a key, key thing now. And there isn’t just one solution – there can be many.”
Coupled with a global commitment to curb climate change, concerns about emissions are not merely powering a shift to zero-emissions motoring, however. Hydrogen is also emerging as a driver of a broader energy transition – away from coal, oil and gas – that is changing society as a whole.
“Hydrogen is going to be the main vector for all key parts of the economy,” insists Pierre-Etienne Franc, a member of the recently formed Hydrogen Council, an international group of chief executives who want to make hydrogen commercially viable. This will include “industry, transportation, heating, power, buffering and storage,” says Franc, who also chairs the Fuel Cells and Hydrogen Joint Undertaking, a European industry-led private-public partnership committed to ever-faster introduction of fuel cells and hydrogen technologies.
At a time when automation and artificial intelligence threaten to make even sophisticated jobs redundant, hydrogen will deliver much-needed work in engineering and related industries, according to a forecast by Illinois-based research centre Argonne National Laboratory. It predicts that 250,000 supply-chain jobs and a further 100,000 manufacturing jobs will be created worldwide by 2050.
Consultancy McKinsey has outlined how hydrogen can play several major roles in the energy transition, and decarbonising transport is one of those, with FCEVs complementing BEVs. “Battery-electric vehicles are making headlines, but fuel cells are gaining momentum – with good reason,” said McKinsey in a report published in November 2017.
In addition, hydrogen can help decarbonise industry, especially when high-grade heat is required, and it can be used to heat buildings, to produce cleaner chemicals and steel, as a chemical feedstock in combination with captured carbon, and as a reducing agent for iron ore, according to McKinsey.
The supply side is changing too, as a result of growing demand for renewable energy, in the wake of technological advances that have made wind and solar much cheaper, and in response to stricter emissions requirements. And here hydrogen can play an important role. Excess renewable energy, such as wind power generated at night when there is little demand for it, can be used to produce hydrogen.
“The beauty of hydrogen is that it can be made using excess energy capacity driven by renewables and then used in a vast range of business applications,” says Jeff Connolly, chief executive of Siemens in Australia and New Zealand.
According to McKinsey, this provision of “a means of long-term energy storage means hydrogen can enable a large-scale integration of renewable electricity into the energy system. It allows for the distribution of energy across regions and seasons and can serve as a buffer to increase energy-system resilience”.
And, when operating on an industrial scale, power-to-gas renewable-energy storage using rapid-response electrolysis to produce hydrogen is “by far the lowest cost, and you can store the energy in the gas grid for years,” says Cooley.
Taken together, we are seeing an ecosystem emerging. “The vehicle user sees fast refuelling and range,” says Cooley. “The air quality people see zero emissions. The power industry sees grid balancing and energy storage.”
John Zagaja, senior vice-president of engineering at Proton Energy Systems, agrees. “The glut of renewable energy makes a business case for hydrogen,” he says. “The biggest challenge now is cost.”
The benefits to the economy, which range from jobs to energy security, and to the environment, in terms of cleaner air and curbed climate change, have been spelt out.
As engineers and chemists keep enhancing the technologies associated with hydrogen – ranging from improved production methods, transport and storage, to better vehicles and infrastructure – this trade-off between cost and benefits will be crucial.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.