They are certainly appearing in showrooms at a remarkable rate and manufacturers are pouring money into their rapid development at the same time as billions of pounds are being spent on charging infrastructure.
However, there is still a debate about whether BEVs are the right solution for every application and several major manufacturers, including Jaguar Land Rover, are also exploring hydrogen fuel cell vehicles (FCEV) as a zero-emissions alternative to BEVs.
What is a hydrogen fuel cell car?
An FCEV uses electric motors to drive its wheels, just like a BEV. However, instead of a lithium-ion battery pack, the motor or motors is powered by electricity created by the splitting of hydrogen molecules in a fuel cell.
How does a hydrogen fuel cell work?
A fuel cell contains an anode, a cathode, and an electrolyte membrane. Hydrogen passes through the anode, where its molecules are split into protons and electrons. The electrons are forced through a circuit, generating an electric current to power the motor, while the protons pass through the membrane. At the cathode, the electrons are reunited with the protons and oxygen to produce water - a FCEV’s only tailpipe emission.
How do you fuel an FCEV, where are the filling stations and is it safe?
An FCEV has a regular fuel tank and is refuelled in a similar way as a petrol or diesel car is now, from a pressurised storage tank via a fuel filler.
The process takes a similar time to refuelling a petrol or diesel car, meaning an FCEV can be refuelled and on its way in a few minutes.
Those behind FCEVs say it’s just as safe as filling up with a “regular” fuel and car makers put their cars’ hydrogen fuel tanks through even more rigorous testing than standard petrol or diesel. Toyota says its Mirai’s hydrogen fuel tank can absorb five times as much crash energy as a regular petrol tank.
However, there are very few filling stations in the UK. According to UK H2 Mobility there are 11 car fuelling stations in the UK. Most are close to the M25 in England’s south-east, with two in Wales, two in Scotland and none in Northern Ireland. A further four are planned.
How much do hydrogen cars cost to run?
Hydrogen cars are expensive to buy and there are only two currently on sale. The Hyundai Nexo is around £70,000 and the Toyota Mirai costs £50,000. That, however, is £15,000 cheaper than the first generation Mirai and hints that costs could come down. It's also comparable to EVs from brands such as Audi, Tesla and BMW.
Once you’ve bought the car, the running costs are currently more than for a conventional or BEV car.
In the UK, hydrogen fuel costs between £10 and £15 per kg (it’s measured in kilogrammes rather than litres). That means filling a Hyundai Nexo’s 6.33kg tank, which offers a claimed 414 miles of range will cost anywhere between £63 and £95 pounds.
With consumption of 0.95kg per 100km (62 miles) that means it will cost around £11.40 to cover 100km (at a cost of £12 per kg). An equivalent diesel with economy of 55mpg (5.1l/100km) will cost around £6.76 to cover the same distance. A petrol with economy of 49mpg (the UK new car average in 2019) will cost £7.48.
To charge a BEV such as the Hyundai Kona, which requires 19.4kWh per 100km, will cost around £2.79 per 100km.
What are the positives of FCEV?
Hydrogen is the universe’s most abundant substance and can be obtained in a number of ways, making it a readily available fuel source. Using it as a fuel source also produces no tailpipe CO2 and the only emissions are water.
Proponents of FCEVs also argue that it can be obtained in an environmentally friendly way using renewable energy and can be extracted from various sources at the filling station rather than being brought in by tanker, meaning it has a far smaller environmental impact than traditional fossil fuels.
The most obvious advantages of an FCEV over a BEV currently lie in refuelling and range. Filling up a car with hydrogen takes around five minutes while even the fastest chargers will take around 30 minutes to fully charge a current EV.
FCEV models such as the Hyundai Nexo and Toyota Mirai have a WLTP range of more than 400 miles and a Mirai recently covered 600 miles on a single tank. Even the longest-range battery EVs can only manage around 300 miles. Linked to the quick refuelling, this gives them an advantage as long-distance vehicles.
Those backing hydrogen power also argue that fuel cells are better suited to heavier purposes including industrial vehicles such as trains, ships and potentially even planes, where batteries cannot produce the required power or longevity. The Stellantis group recently announced plans for FCEV versions of its mid-sized cargo vans, including the Vauxhall Vivaro, to offer long range and quick refuelling to businesses in place of combustion engine or BEV models.
What are the negatives?
One of the challenges facing FCEVs at the minute is that there aren’t many hydrogen fuelling stations. Major fuel brands including Shell are moving to install facilities but at the moment there are only 11 in the whole of the UK and fewer than 200 across Europe.
There are also questions over the environmental impact of harvesting the hydrogen in the first place. The most common ways to obtain it are by breaking down water through electrolysis or from natural gas. Doing this requires electricity, so unless this is 100 per cent renewable there are still CO2 emissions associated with the hydrogen production. Breaking down natural gas also produces carbon dioxide as well as hydrogen. However, those backing FCEVs argue that the CO2 emitted is still far less overall - up to 30 per cent - than in running a conventionally fuelled car. They also argue that with the correct production methods and using different sources, such as biomass, FCEVs could have lower lifetime CO2 impact than a BEV.
Pricing is also a major hurdle. The Mirai costs from £49,995 and the Nexo £69,495 while a BEV with a 280-mile range such as a Hyundai Kona Electric or Kia e-Niro costs around £35,000 and BEVs start at less than £20,000.
Most major manufacturers are experimenting with FCEVs but whether they become a mainstream alternative to BEVs or are used mainly for freight and passenger transport remains to be seen.