Skip to content
British Broadcasting Corporation

Next stop, hydrogen-powered trains

University of Birmingham The hydrogen-powered train Hydroflex is soon to have its first outing on the UK mainline track (Credit: University of Birmingham)University of Birmingham
The hydrogen-powered train Hydroflex is soon to have its first outing on the UK mainline track (Credit: University of Birmingham)

As old diesel trains are phased out of rail networks around the world, the UK is about to test a new type of engine that could help to decarbonise railways – hydrogen-powered trains.

From the platform it looked like any other British commuter train. But as several hundred passengers climbed on board the steel-bodied carriages at Long Marston, they were met with an unusual sight. In one of its cars, passengers were encouraged to perch around four hydrogen fuel tanks, a fuel cell and two lithium batteries.

 

The train’s hydrogen power system produces sufficient power to take the train 50 to 75 miles. The train, called Hydroflex, is the UK’s first to be powered by hydrogen. It was being shown off to the public in June 2019 for the first time on the tracks at the Quinton Rail Technology Centre, a test facility at Long Marston, near Stratford-upon-Avon, in England.

 

Engineers who developed the new train, from the University of Birmingham and British rail company Porterbrook, wanted passengers to sit alongside the train’s hydrogen fuel cells. The sooner they would become familiar with the technology, the sooner they would feel safe, they reasoned.

 

Some apprehension around hydrogen as a fuel source is perhaps understandable considering the unfortunate history of hydrogen-filled dirigibles, namely airships such as the ill-fated British R101 and the German Hindenburg. But hydrogen-powered trains have been emerging as a viable – and much safer – means of transport. How close are we to fleets of trains that release only water as a waste product?

 

You might also like:

 

The way hydrogen powers a train like the Hydroflex is quite simple. The fuel cell is made up of an anode, a cathode and an electrolyte membrane. The stored hydrogen passes through the anode, where it is split into electrons and protons. The electrons are then forced through a circuit that generates an electric charge that can be stored in lithium batteries or sent directly to the train’s electric motor. The leftover part of the hydrogen molecule reacts with oxygen at the cathode and becomes the waste product – water.

 

The Hydroflex’s hydrogen tanks, fuel cell and batteries currently sit inside a passenger car, but the ultimate plan is to store them underneath the train in order to fit in more passengers. Hydrogen is of course extremely flammable, but on the Hydroflex it is stored in four secured high-pressure tanks, one of a range of measures to ensure passengers’ safety.

University of Birmingham Hydrogen-powered trains like Hydroflex are emissions free - provided their hydrogen comes from a renewable source (Credit: University of Birmingham)University of Birmingham
Hydrogen-powered trains like Hydroflex are emissions free - provided their hydrogen comes from a renewable source (Credit: University of Birmingham)

In the midst of the climate crisis, the demand for decarbonisation across transport industries has grown and the Hydroflex is just one product of that. In 2016, Germany unveiled the Coradia iLint, the world’s first hydrogen-powered train, which can run for 600 miles on a single tank of fuel – on par with the distances that traditional trains achieve on a tank of diesel. Engineers in the US are also working on bringing a version of a “hydrail” to the states. However, since rail is already among the lowest greenhouse gas emitters in transportation, it remains to be seen whether the value of a massive overhaul of rail systems will be worth it.

 

The UK already has 42% of its route miles electrified, according to the Institution of Mechanical Engineers, meaning those trains are ready to become zero-carbon, if they use a renewable source of power. A single line running to London from Hampshire is currently the only one in the world to run solely on solar power. However, the remaining 58% of UK track is not yet electrified, so diesel trains are still needed to keep those areas connected by rail.

 

Engineers working on the Hydroflex say that hydrogen-powered trains could be the answer to decarbonising the UK’s rail system without incurring the high cost of electrifying its track. According to an assessment of 20 lines in Britain and mainland Europe, electrifying a single kilometer of track can cost £750,000 to £1m ($965,000 to $1.3m). Hydrogen-powered trains are less expensive, because they don’t require massive track overhauls and they can be created by retrofitting existing diesel trains. This is especially beneficial in rural areas where there are more miles to cover, but fewer passengers to justify the expense.

Getty Images The German Coradia iLint was the world's first hydrogen-powered locomotive (Credit: Getty Images)Getty Images
The German Coradia iLint was the world's first hydrogen-powered locomotive (Credit: Getty Images)

But hydrogen trains come with their own challenges.

 

“We store about 20kg of hydrogen, and that is enough to run the fuel cell for three hours,” says Stuart Hillmansen, professor at Birmingham University and leader of the Hydroflex project. As such, longer-distance journeys wouldn’t yet be feasible. Engineers at the University of Birmingham’s Centre for Railway Research and Education, Porterbrook’s partner on the Hydroflex, are working on ways to extend these limits.

With our current hydrogen storage technologies, hydrogen takes up significantly more space than equivalent fossil fuels do – Raphael Isaac

And while hydrogen fuel cells can be as energy-efficient as diesel fuel, storing the gas can be a problem. “While hydrogen has a lot of energy per mass, because it is super light, it also takes up a lot of volume,” says Raphael Isaac, a researcher on fuel alternatives in rail at Michigan State University's Center for Railway Research and Education. “With our current hydrogen storage technologies, hydrogen takes up significantly more space than [equivalent] fossil fuels do.” Even though hydrogen is typically compressed, it’s still not as efficient per unit volume as fossil fuels.

It’s also a space issue on trains. The fuel tanks on the Hydroflex, for example, have to be small enough to fit in an ordinary car that can pass through Victorian-era railway tunnels. These space constraints are one reason that Porterbrook chose to retrofit older train models with the hydrogen fuel power system, rather than construct entirely new vehicles like the Alstom did in Germany – the existing trains were already made to measure for the tunnels they had to pass through.

Hydrogen can be produced using other methods and from renewable energy sources, e.g. electricity from solar photovoltaics and electrolysis of water – Margaret S. Wooldridge

Even though the only direct waste product of hydrogen fuel is water, obtaining this form of power is not squeaky clean. “The challenge is, at the moment hydrogen is made as a byproduct of chemical processes,” says Helen Simpson, innovation and projects director at Porterbrook. The cheapest and most common method at present uses natural gas and high-temperature steam to produce hydrogen. Hydroflex runs on a hydrogen produced using natural gas but its supplier, BOC, says it is looking into renewable options.

 

In order for hydrogen power to be truly sustainable, other methods of producing it that don’t rely on fossil fuels would need to become mainstream. “Hydrogen can be produced using other methods and from renewable energy sources, e.g. electricity from solar photovoltaics and electrolysis of water,” says Margaret S. Wooldridge, an aerospace engineer at the University of Michigan.

 

Electrolysis creates hydrogen by separating oxygen from water using an electric current. That current can be created using energy from renewable energy sources, but it has yet to be done outside of small test demonstrations. In order to be a truly green form of travel, the hydrogen would need to be created and stored using renewable energy sources, like off-shore wind farms and solar grids, rather than fossil fuels.

 

Another lingering environmental issue with hydrogen-powered trains is their use of lithium batteries. Currently, lithium processing takes a major toll on the surrounding environment. Mining one tonne of lithium requires 500,000 gallons of water, for example, and lithium mining has been linked to several measures of environmental degradation. Researchers hope that in the future it may be feasible to extract lithium from seawater instead using solar power, but the idea remains experimental.  

Getty Images Hydrogen trains have potential to be particularly useful in areas with large distances to cover and lower passenger demand (Credit: Getty Images)Getty Images
Hydrogen trains have potential to be particularly useful in areas with large distances to cover and lower passenger demand (Credit: Getty Images)

On the flipside, one major benefit of trains like the Hydroflex is their potential as a bi-mode train, meaning they can run on the electrified or conventional lines alike. So even though there is certainly an expense to building new hydrogen-powered trains (one of the Alstrom hydrogen trains costs approximately £5.19m), or retrofitting older ones, they are a flexible alternative while the majority of lines – especially rural ones – are yet to be converted to carry electric-trains.

 

“This is really the space where hydrogen fuel comes in as a real cost-effective and valuable alternative and delivers a low-carbon railway,” says Simpson. “Where we’ve got all these long routes that don’t have as much passenger demand, the cost-benefit of electrifying the lines isn’t there.”

 

There are benefits to passengers too. Hydrogen-powered trains, like electric trains, are also incredibly quiet compared to their diesel counterparts. And unlike electric trains, they are more resilient to network-wide disruption. “The shared electric infrastructure means that if there is damage to the infrastructure, the operations of many trains on a line will be impacted,” says Isaac. A hydrogen powered train could switch over to its fuel cells if the electricity lines went down, for example.

There is a huge challenge in terms of developing the infrastructure to supply the hydrogen to the railway – Stuart Hillmansen

In countries where passenger trains are less popular, like the US, the ability to convert freight trains to hydrogen power will be key to making the case for mass producing them. A recent report sponsored by the US Energy Department and Federal Rail Administration notes that while powering freight trains with hydrogen is more technically challenging, it would ultimately have “the highest societal value”. Freight is, however, heavier than passengers, so it would require more hydrogen, or more efficiently compressed hydrogen, to carry the same load the same distance that diesel-fueled freight trains currently manage.

 

The engineers at Birmingham are currently working on more efficient ways to compress hydrogen, one of several hurdles Hydroflex still has to navigate. “There is a huge challenge in terms of developing the infrastructure to supply the hydrogen to the railway,” says Hillmansen. “This technology exists, but there will need to be an uplift in the scale of these operations.”

 

But the engineers emphasise that Hydroflex is not just a demonstration of hydrogen-power technology – it is set to become a viable commercial train, with mainline testing expected to begin in March or April this year. There a long list of approvals the train needs to pass in order to be considered safe for commercial use, but those involved in the project estimate Hydroflex will be fully up and running as soon as two years from now.

 

In the light of the UK’s ambition of doing away with diesel-only trains altogether by 2040, the Hydroflex’s forthcoming springtime test on the tracks makes it perhaps one of the most keenly anticipated arrivals in the country.

--

The emissions from travel it took to report this story were 0kg CO2: the writer interviewed sources remotely. The digital emissions from this story are an estimated 1.2g to 3.6g CO2 per page view. Find out more about how we calculated this figure here.

--

Join one million Future fans by liking us on  Facebook, or follow us on  Twitter or  Instagram.

If you liked this story,  sign up for the weekly bbc.com features newsletter, called “The Essential List”. A handpicked selection of stories from BBC Future, Culture, Worklife, and Travel, delivered to your inbox every Friday.

Watch
More

玻璃钢生产厂家吉林多彩玻璃钢雕塑玻璃钢花盆装饰摆件玻璃钢粉红豹雕塑厂家泉州邯郸不锈钢仿古玻璃钢卡通雕塑扬州长方形玻璃钢花盆北京景区玻璃钢雕塑优势买玻璃钢卡通雕塑商用合法吗红色玻璃钢雕塑商场店庆美陈高级感达州玻璃钢雕塑制作厂家深圳玻璃钢雕塑灯定制水果玻璃钢雕塑定做价格菏泽铸铜校园玻璃钢景观雕塑厂家玻璃钢雕塑有什么特征山东大型商场美陈哪里有宁夏雕塑玻璃钢江门透光玻璃钢雕塑摆件福建通道商场美陈制造安徽人物玻璃钢雕塑供应商周口玻璃钢喷泉雕塑厂家江苏通用玻璃钢雕塑厂家供应耐腐蚀玻璃钢雕塑价格如何计算秀英玻璃钢雕塑厂家芜湖蓝星玻璃钢雕塑厂宁河玻璃钢雕塑公司南京玻璃钢花盆定做宝鸡玻璃钢花盆批发商丘抽象玻璃钢仿铜雕塑清城玻璃钢花盆花器玻璃钢雕塑做颜色流程香港通过《维护国家安全条例》两大学生合买彩票中奖一人不认账让美丽中国“从细节出发”19岁小伙救下5人后溺亡 多方发声单亲妈妈陷入热恋 14岁儿子报警汪小菲曝离婚始末遭遇山火的松茸之乡雅江山火三名扑火人员牺牲系谣言何赛飞追着代拍打萧美琴窜访捷克 外交部回应卫健委通报少年有偿捐血浆16次猝死手机成瘾是影响睡眠质量重要因素高校汽车撞人致3死16伤 司机系学生315晚会后胖东来又人满为患了小米汽车超级工厂正式揭幕中国拥有亿元资产的家庭达13.3万户周杰伦一审败诉网易男孩8年未见母亲被告知被遗忘许家印被限制高消费饲养员用铁锨驱打大熊猫被辞退男子被猫抓伤后确诊“猫抓病”特朗普无法缴纳4.54亿美元罚金倪萍分享减重40斤方法联合利华开始重组张家界的山上“长”满了韩国人？张立群任西安交通大学校长杨倩无缘巴黎奥运“重生之我在北大当嫡校长”黑马情侣提车了专访95后高颜值猪保姆考生莫言也上北大硕士复试名单了网友洛杉矶偶遇贾玲专家建议不必谈骨泥色变沉迷短剧的人就像掉进了杀猪盘奥巴马现身唐宁街 黑色着装引猜测七年后宇文玥被薅头发捞上岸事业单位女子向同事水杯投不明物质凯特王妃现身！外出购物视频曝光河南驻马店通报西平中学跳楼事件王树国卸任西安交大校长 师生送别恒大被罚41.75亿到底怎么缴男子被流浪猫绊倒 投喂者赔24万房客欠租失踪 房东直发愁西双版纳热带植物园回应蜉蝣大爆发钱人豪晒法院裁定实锤抄袭外国人感慨凌晨的中国很安全胖东来员工每周单休无小长假白宫：哈马斯三号人物被杀测试车高速逃费 小米：已补缴老人退休金被冒领16年 金额超20万

玻璃钢生产厂家 XML地图 TXT地图 虚拟主机 SEO 网站制作 网站优化