It now wants to outlaw the sale of fossil fuel cars by 2035 and has extended its plans to cover hybrid vehicles as well.
As a result, a lot of attention has turned to battery electric vehicles (BEVs), which the Government is expecting to fill the gap left by internal combustion cars.
However, alongside BEVs there is another class of zero-emissions car that could help replace conventionally fueled ones - hydrogen fuel cell vehicle (FCEVs).
What is hydrogen fuel cell car?
Simply put, an FCEV is an electric car where the motor or motors is powered by electricity created by the splitting of hydrogen atoms rather than from a traditional battery stack.
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 them, 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. Most are close to the M25 in England’s south-east, with two in Wales, two in Aberdeen, and one each in Coventry, Sheffield, Swindon and on Orkney.
How much do hydrogen fuel cell cars cost to run?
Hydrogen cars are expensive to buy. The Hyundai Nexo is around £65,000 and the previous generation Toyota Mirai was a similar price.
Once you’ve bought the car, the running costs are also 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 around 414 miles of range will cost anywhere between £63 and £95 pounds.
With consumption of 0.95kg per 100km (62miles) that means it will cost around £11.40 to cover 100km in a Nexo (at a cost of £12 per kg). An equivalent diesel with economy of 55mpg (5.1l/100km) will cost around £6.72 to cover the same distance.
Charging a BEV such as the Hyundai Kona, which requires 19.4kWh per 100km, will cost around £3 at 15.5p per kWh.
What are the positives of hydrogen cars?
Hydrogen is the universe’s most abundant substance and can be obtained in a number of ways, making it a readily available fuel source.
The 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. 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.
And the only tailpipe emission is water, meeting demand for cars that produce no CO2 emissions.
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 16 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 natural gas.
Electrolysis of water 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.
Pricing is also a major hurdle. The only FCEV currently on sale in the UK costs nearly £70,000 while a BEV with a 280-mile range such as a Hyundai Kona Electric or Kia e-Niro costs almost half that. And there are the relatively high fuelling costs to consider.
What FCEVs are available in Britain?
There is currently only one FCEV model on sale in the UK - the Hyundai Nexo - and it costs £65,995.
Toyota’s Mirai was a pioneer in FCEV and a new version of that is due in 2020 but it will cost a similar price.
The second generation of Toyota Mirai is due to be launched later in 2020 (Photo: Toyota)
Other brands are investigating FCEVs but there are no confirmed new models for the UK yet. Mercedes has built the GLC F-Cell SUV but it’s not currently available in the UK and Audi and BMW are planning their own FCEVs but these will not arrive for at least another two years.
There is also a homegrown FCEV firm looking to introduce its own car to the market. Riversimple’s Rasa is a compact two-seat car with a range of around 300 miles. The company has produced several prototypes and plans to offer the car on a lease-only arrangement but it is not currently available to the public.
Do hydrogen cars have a future?
Tesla’s Elon Musk has dismissed FCEVs as “incredibly dumb” but, as a man who owns a battery electric car company, that’s hardly surprising.
He argues producing hydrogen fuel is less efficient that producing electricity for battery EVs. The counter argument is that hydrogen can be produced in a zero-emissions manner and offers the convenience of quicker fuelling and longer range than lithium-ion powered EVs.
The big question for FCEV is are they too late to the party? Battery EVs like the Nissan Leaf, Tesla Model 3 and Jaguar I-Pace are increasingly commonplace on our roads and the UK Government has clearly thrown its weight behind plug-in vehicles with the promise of £400m to expand charging infrastructure. What’s more, EV range and charging abilities are improving all the time. The new Leaf can hit 80 per cent charge in as little as an hour and VW says its ID3 all-electric hatchback will do up to 341 miles on a charge.
Hyundai, Kia and Toyota say their latest FCEVs are fully commercial viable vehicles with realistic lifespans, unlike the early examples, but they’re already playing catch-up. In their favour, the longer range and rapid refuelling ease many of the worries motorists have around EVs but that’s only relevant if there are enough fuelling stations.
There’s also the expense. You can get a Leaf or Zoe for less than £30k but the Nexo costs more than £65,000 and the new Mirai likely to be a similar price. Hyundai/Kia’s head of FCEV research Dr Sae-Hoon Kim argues that the more people who buy FCEVs, the cheaper they’ll get but, as with the fuelling stations there’s a chicken and egg scenario where people will only start to buy them when they reach mainstream prices.