What is a Hydrogen Vehicle?

Within our lifetimes, we’ve seen technology advance faster than we can keep up with. Regular combustion engines are rapidly phasing out toward greener alternatives, automated driving is all over the news, and new materials make car buying more affordable. The power of hydrogen is another advancement peeking its head around the corner, and it will become a norm sooner than we might think. Let’s shine a light on this exciting development by exploring the question ‘What is a Hydrogen vehicle?’.

Why Hydrogen?

Hydrogen is right at the top of the periodic table, which means its abundant. In fact, it’s the most abundant gas in the known universe. This makes it very accessible with the right tools. But what about its performance as a fuel? By comparing the efficiency of hydrogen to regular fuels, it was found it’s three times more efficient. Handy, right?

So why haven’t we thought of using this earlier? Well, we have. One of the first hydrogen vehicles was invented in 1966 by General Motors, called the Chevrolet Electrovan… but to scale hydrogen power to an industrial scale is another challenge entirely. Hydrogen (H) is rarely found on its own – it’s usually found as part of a bigger compound. Think H2O (water) or CH4 (methane). We’re going to need to “crack” the hydrogen from its compound so we can use it. This requires energy, and a lot of it. While hydrogen cars have been around for a while, it’s only recently that technology has allowed them to become more reliable and cost-effective.

Then there’s the problem of its volatility. Hydrogen can be flammable, even explosive in some situations. The logistics and safety measures needed to transport hydrogen around on a country-wide scale are complex and are sure to cause problems without the correct protocols. But solving these problems isn’t out of reach, in fact, they are almost within the palm of our hands.

But enough with shaming hydrogen - let’s go back to its benefits because they sure outweigh the cons. Due to its lightweight nature, hydrogen is easy to store and transport, and you can pack a lot of it in a small space. It’s energy-dense too, so even a small quantity of it can go a long way in terms of power output. One of the biggest benefits is its green by-products. Hydrogen vehicles only produce water (steam), which makes it far more sustainable that regular fossil fuels. For a carbon-neutral future, hydrogen infrastructure needs to level up to larger industries like power supply or transport. Even current fuelling stations in the UK are only located in cities (although they are showing steady growth in frequency).

How Does this Apply to Vehicles?

Hydrogen vehicles are all about fuel cells. A fuel cell is an electrochemical unit that produces electricity through the reaction of chemicals, hence ‘electro’+’chemical’. The chemicals inside a fuel cell are hydrogen (in its raw form) and oxygen. When these two elements are reacted, heat and electricity are produced. Of course, combining hydrogen and oxygen will produce water (H2O), which is the by-product/fumes from the fuel cell.

Hydrogen vehicles are called fuel-cell electric vehicles (FCEVs). Like a regular EV, the electricity produced by this reaction is used to power an electric motor, which in turn powers the wheels of the vehicle. In FCEVs, hydrogen is stored in a compressed form, but can be transported in a liquid or gaseous form, although the former of these requires temperatures of -253°C!

Want to get technical? Let’s dive into how fuel cells actually work (you can skip this part if you’re more interested in the bigger picture stuff). In an FCEV, there isn’t just one fuel cell, but multiple called a ‘stack’. Each cell in a fuel cell stack contains an anode, cathode, and electrolyte membrane – the basic requirements for ‘electrolysis’. Hydrogen is fed into the anode which splits it (through a platinum catalyst) into protons and electrons, each going a different direction. The electrons travel through an external circuit which generates electricity to power the motor.

The protons from the hydrogen instead travel through the electrolyte membrane to the cathode. At the cathode, oxygen is fed into it to meet the hydrogen protons and electrons from the circuit. These combine to produce water vapour to be released out of the vehicle exhaust. A small battery is typically integrated into an FCEV to assist the motor and utilise regenerative braking just like a regular EV.

Why FCEVs?

Check out the summary below of why FCEVs have so much potential:

• Zero emissions: Pumping steam into the atmosphere is about as green as you can get!
• Quiet driving: The chemical processes inside a fuel cell won't racket your ears every time you use the accelerator.
• Quick refuelling: A big advantage FCEVs have over regular EVs is their ability to refuel in just a few minutes with hydrogen gas.
• More efficient: FCEVs are three times more efficient than regular ICEs, meaning they can cover over 300 miles on a single fuelling with ease.

Are Hydrogen Cars Safe?

Because the hydrogen stored in a vehicle is within a high-pressure cylinder, concerns have been raised over "are hydrogen cars safe" and their stability during a crash or high temperatures. Luckily, all current hydrogen vehicles have passed the most rigorous of safety tests, even in the worst-case scenarios. Today, hydrogen tanks can even withstand a high-velocity impact (such as repelling a bullet).

Are Hydrogen Cars Safe in Low Temperatures?

Like EVs, there’s also the problem of cold temperatures. Hydrogen can be less efficient at low temperatures, therefore reducing the driving range. However, this problem has been mitigated with the implementation of heating systems to improve fuel cell efficiency.

As for hydrogen itself, it’s cleaner and safer to handle than petrol/diesel. Upon exposure to hydrogen gas, low concentrations will be generally safe to breathe. Because hydrogen gas is lighter than air, it rapidly dissipates into the atmosphere in the event of a leak. This significantly reduces the chances of a fire or explosion whereas, for petrol/diesel, it collects rather than dissipates.

What we need to recognise is that whether you choose an ICE, EV, or FCEV, you will always have a flammable element within its system. By balancing the risks involved with each, along with the increasing demand for safer and more protected vehicles, hydrogen is indeed a safe form of fuel, if not more so, than any other vehicle.

Are Hydrogen Cars Safe in an Accident?

Hydrogen cars are engineered with safety in mind. In accidents, hydrogen fuel cells pose minimal risk. Tanks are robust and designed to withstand impact. Hydrogen quickly disperses into the atmosphere, minimizing fire risk. Rigorous safety standards govern these vehicles, ensuring they are as safe as traditional gasoline-powered cars in collisions.

Are Hydrogen Cars Safe for the Environment?

Hydrogen cars are environmentally friendly. Emitting only water vapour and no harmful pollutants during operation, they contribute to cleaner air and combat climate change. Hydrogen production methods are evolving to become more sustainable, utilizing renewable energy sources. As infrastructure grows, hydrogen cars promise a greener future for transportation.

What are Some of the Different Hydrogen-Powered Cars UK?

Hyundai has only recently introduced the NEXO Hydrogen SUV, and it’s everything we hoped for in a sustainable vehicle. By employing the same FCEV technology as mentioned, the NEXO offers a refuelling time of only five minutes and an impressive range of over 400 miles. The NEXO shows off as a viable alternative for everyday commuting due to its second-generation fuel cell consuming as little as 1kg of hydrogen per 100km!

Stepping into the Vauxhall fleet is the Vivaro-e Hydrogen van. Offering a 249-mile range on a rapid three-minute refuelling stop, the Vivaro-e Hydrogen will pave the way for practical and sustainable vehicles. A cargo volume of 6.1m3 and a cargo load of 1100kg is more than appealing because Vauxhall has kept the same features that buyers love while overhauling the powertrain into an exciting alternative. The Vivaro-e Hydrogen is right around the corner, so keep an eye out on our website for updates!

Many other FCEVs are in development or are already showing real-life usage, including the Toyota Mirai. While there isn’t a vast selection of FCEVs out there yet, EVs are a great choice while we wait as their infrastructure is rapidly advancing... check out our range here.