Advice

Hydrogen fuel cell cars: everything you need to know

You might have heard people talking about hydrogen or fuel cell cars, and wondered what they are, if you should buy one, and if you can buy one.

Words by: First published: 5th September 2018
A car that only emits pure water at the tailpipe, takes the same amount of time to fill the tank as it would a petrol or diesel car, and has the same amount of range sounds pretty great right? No emissions, no range anxiety, no waiting around for your electric vehicle to charge… but how feasible is a hydrogen or fuel cell car, compared with an electric car, or a petrol or diesel? Here’s everything you might want to know.
Apparently there are alternatives to battery-electric cars (EVs) called fuel cell – or hydrogen – cars. What are they exactly?
In scientific terms, a fuel cell is a catalytic electricity generator fuelled with hydrogen gas. It works on a principle discovered by Welsh scientist Sir William Grove, in 1839. However, the fuel cell wasn't really a feasible electricity producer until the mid-20th century. In 1955, General Electric produced the first hydrogen-and-oxygen fuel cell, which was given a long name: a proton-exchange membrane (PEM) fuel cell. NASA used a PEM fuel cell to generate power for the Gemini Space Mission in the 60s. Since then, the PEM fuel cell has been used in all fuel cell cars.
Is a hydrogen fuel cell car a pretty eco-friendly method of transport?
Yes and no. Yes, because there's a pleasing engineering simplicity about a fuel cell; you start with water, which you electrolysise using surplus off-peak grid electricity into hydrogen and oxygen, which you feed into a fuel cell, which emits water and electricity. But, we're a long way from there at the moment, and most supplies of hydrogen are steamed out of natural gas, which is a fossil fuel, so there's only a small environmental benefit in a fuel cell.
Is a hydrogen fuel cell car more practical than a battery electric (EV) equivalent?
It should be, as refuelling with hydrogen takes the same time as refilling your tank with petrol or diesel, and the range of a fuel cell is generally greater than the average battery electric car. So in theory, there's no range anxiety with a fuel cell.

In practice, however, there is, as there are just 12 refuelling stations in the UK. This in spite of words from government ministers and the best efforts of companies such as ITM, which has recently teamed up with Shell to build electrolysing plants to supply renewable hydrogen filling stations. While many European governments have zero-rated hydrogen fuel for cars, our government hasn't.
Is a battery electric (EV) car better for the planet than a hydrogen car?
Not as much as some car makers claim. For a start, the electricity used to recharge electric cars has a carbon dioxide (CO2) contribution. Last year, the CO2 contribution of the UK's electricity generation industry was 470g/kWh, which means cars like the Hyundai 64kWh Kona EV have a well-to-wheels CO2 contribution of about 62g/km.

There are other issues with batteries and the motors that drive the cars, too. As well as lithium, batteries and electric motors are full of rare minerals and rare earth metals. Take cobalt for example, which is a by-product of mining copper and nickel: a typical battery vehicle requires between 5-10kgs of it. Over 60% of the world's cobalt is mined in the Democratic Republic of Congo, where child labour is rife and environmental controls are minimal. As a result of cobalt's scarcity, prices have tripled in the last two years, from about £18,250 to more than £61,000 per ton.

There's also the problem of what to do with the batteries at the end of their lives. Some can have a second life as buffers for solar and wind-generated electricity, but eventually they all get buried in the ground to avoid short-circuit fires.

The ethics and sustainability of lithium-ion batteries (which are used in EVs) is also beginning to worry car makers, who are looking at the full eco and ethical implications of alternative powertrains.

By contrast, fuel cells are recyclable using known technology, as they use a platinum catalyst, which is more widely available as it used in conventional exhaust catalysts.
Isn’t hydrogen dangerous? Didn't it cause the 1937 Hindenburg disaster?
There are various theories about what caused the Hindenburg disaster, but most of them suggest there was a secondary source of ignition for the hydrogen. However, pressurised hydrogen is dangerous and in certain concentrations it can explode. It burns with a low radiant heat, though, which means you don't get burned unless you are close to it. And in copious puncture and crushing tests, the pressurised hydrogen tanks in modern fuel cell cars vent the gas to air quickly. By contrast, lithium-ion batteries can short circuit and go into what is termed 'thermal overload'. And of course, and petrol and diesel vehicle fires aren't unknown, either.
How many fuel cell cars are out there?
Not many. Almost all car makers have had a go at fuel cells, but few have stuck with it for long, as the technological hurdles have proved so difficult and the costs so high. There were American tractors powered by fuel cells in the 50s, but the first car maker to use the technology was Mercedes-Benz with its 1993 Necar I van. Mercedes subsequently refined the technology through various A-Class models into the current B-Class fuel cell prototypes, called the F-Cell.

Ford and General Motors took over leadership in the field, until the Japanese and South Koreans got involved. With few oil reserves of their own, the Far Eastern economies have identified fuel cells as viable future technology, and now Toyota and Hyundai have fuel cell vehicles you can lease or, in the case of Hyundai's Nexo, purchase outright. In the next few years, however, we are expecting to see fuel cell vehicles on sale from Mercedes-Benz, Honda and General Motors.
How much is a fuel cell car and what does it cost to run?
Fuel cell cars are not cheap, and are generally more expensive to buy than electric cars too.

Working out relative running costs depends on what you are paying for fuel. In the UK, hydrogen costs about £12 per kg, which means a 62-mile (100km) journey in the Hyundai Nexo for example (which does 0.95kg/100km), will cost about £11.40. In Norway, where renewable hydrogen is untaxed and costs 8.99 krone (84p) per kg, the same 62-mile journey will cost just 80p.

By contrast, if you recharge an EV (which does 14.3kWh per 100km) via a wall box using a household rate of about 16p per kWh, that same journey will cost about £2.28.

An equivalent diesel-powered car (doing 4.4-litres/100km) would cost around £5.81 for a 100km journey (diesel at £1.32 a litre), with a petrol-powered car (5.6-litres/100km) costing around £7.11 for that 100km (petrol at £1.27 a litre).

Should I buy a hydrogen car?
Right now, the technology and the fuel are too expensive, and there aren't enough filling stations, although all that is likely to change. In the long-distant future, fuel cells are likely to be the answer, and it's hard to find a mass-manufacturing car company that doesn't agree. The trouble is, fuel cells have been the coming thing now for over 30 years and they still haven't truly arrived as practical everyday transport, and there are some out there who think they are in danger of missing the alternative-fuel boat...

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