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What is a hydrogen fuel cell car?

  • Guide to hydrogen fuel cell vehicles
  • Find out what they are and how they work
  • Are hydrogen fuel cell cars the future?

A hydrogen fuel cell electric vehicle (FCEV) is one that uses compressed hydrogen to generate electricity, which is then used to power the car.

For that reason they drive a lot like an electric vehicle – silently with instant torque - but with a far longer range thanks to the on-board generation of electricity.

Their main attraction is that they emit nothing more harmful than clear air and water. In fact, Hyundai claims the Nexo actually ‘scrubs’ particulates from the air, in essence cleaning the outside environment as it drives through it.

Fuel cell vehicles we've reviewed:

Toyota Mirai

Toyota Mirai

Hyundai Nexo

Hyundai Nexo

Honda Clarity

Honda Clarity

What are the drawbacks?

Hydrogen itself is also the most abundant element in the atmosphere, so there’s no shortage of it, but at time of publication it does cost a vast amount to prepare and compress it so it’s suitable for use in a car, hence the tiny number of refuelling stations in the country.

The other main disadvantage is the sheer amount of electrical energy required to create the hydrogen in the first place – ironically in a lot of cases predominantly generated using fossil fuels. We’re not living in a society that’s truly geared-up for hydrogen fuel cell motoring just yet.

How do hydrogen cars work?

The science behind fuel cell electric vehicles is incredibly complex, but in a simplified sense a hydrogen fuel cell creates electricity, which is then used to feed a battery or drive the wheels, or a combination of the two.

Hydrogen fuel cell

Said electricity is produced in a unit called a fuel cell stack, in which a chemical reaction occurs that converts hydrogen into electricity, clean air and water.

You’re able to refill a hydrogen car with compressed H2 in around the same time it takes to top up a conventionally engined car with petrol or diesel, but this depends on the type of filling point you’re using. More advanced (and expensive) units can refill in as little as five minutes, while lesser ones work at lower pressure and so can’t refill as quickly.

Are hydrogen fuel cell cars safe?

While the thought of driving around with tanks of pressurised hydrogen may sound a little worrying, car firms and their suppliers have been working on such technology for years and there’s little reason to expect anything other than total reliability.

Refilling a hydrogen fuel cell car

The carbonfibre tanks are tested to remarkable lengths, including getting shot with various military hardware and dropped from significant heights.

And much of the other hardware used is similar or the same as that in electric vehicles, so again there’s little to worry about there. We’ve heard no anecdotal reliability issues with these either.

Are hydrogen cars the future?

They’re certainly not suitable for many buyers as things stand right now, simply because there aren’t many hydrogen filling stations in the UK. However, considering the massive benefits of this type of power generation compared with using fossil fuels – either in conventional combustion engines or to run the national grid – it’s likely we’ll see the infrastructure growing increasingly quickly.

Hydrogen fuel cell filling station

It’s going to rely heavily on investment, both from large multinational companies and governments, in order to grow at any pace, though. For that reason it’s likely we’ll see an increasing number of commercial vehicles powered by hydrogen first. The most cost-effective use case is something like a city bus, which is filled at the bus station only.

This means an entire fleet can use one filling point, dramatically improving the business case for the multi-million pound investment required. 

Will all cars be hydrogen fuel cell vehicles? 

This seems unlikely. While no-one knows exactly what'll happen moving forwards, the basic premise is that battery technology could progress to be as efficient as a fuel cell vehicle. This is because effectively a fuel cell vehicle stores its energy in hydrogen, which is then converted to electricity. If the battery can store enough for most drivers' useage on its own, then we wouldn't need the fuel cell at all. 

Hydrogen fuel cell in Toyota Mirai

It's already becoming clear that for short-range work, such as inner cities, the best solution is a small electric car that can be quickly recharged. As charging times drop and battery technology improves, so the requirement for hydrogen fuel cell vehicles falls. Whether that'll happen quickly enough is anyone's guess, though. 

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Looking for more jargon-busting motoring meanings? Head over to our Parkers Car Glossary page and take a look at our other definitions.