Are hydrogen cars the future?

Rewind twenty years or so, and car makers were predicting an electric vehicle future, but not one involving batteries. Instead, cars would be powered by fuel cells. 

Battery cars use energy generated elsewhere, fuel cell ones use a chemical process (called reverse electrolysis) to create electricity on board. This involves taking hydrogen and compressing it up to 700 times atmospheric pressure, squirting it into a very strong tank then feeding it into a box with membranes of precious metals such as platinum. 

As the hydrogen passes through the membranes a chemical process creates electricity and water vapour, or steam, which is the process’s only by-product. The electricity can then be used to drive the car along. 

Such cars take about five minutes to re-fuel, have ranges that aren’t that far behind petrol or diesel cars, and unlike pure electrics, don’t become less efficient in cold weather.

This sounds like a winning combination, yet fuel cell cars have been completely eclipsed by battery electrics ever since Tesla’s Elon Musk proved they could be usable and cool.

A seasoned practitioner of the pithy insult, Musk coined the term ‘fool cells.’ He thinks it's nuts to generate electricity on board a car, as the components that do this are heavy and take up space. 

Musk also suggests that the process to create the hydrogen is potentially pollutive - petrochemical plants already do this as a by-product of their activities, although wind and solar power can be used too- but either way creating hydrogen saps energy.

Hydrogen stations are rare and expensive to build

Pure electric car batteries are heavy too, but the interface between power and vehicle is more direct and requires less technology. Tesla-owning motoring pundit Quentin Willson agrees. “Take 100 watts of electricity produced by a wind turbine. It has to be turned in to hydrogen, compressed, chilled, moved by tanker then power the car. By then, you only get about 30 per cent of that 100 watts. Electric cars are around 85 per cent efficient.’

Robert Steinberger-Wickens is the University of Birmingham’s professor in fuel cells and hydrogen research. Oddly enough, the professor takes a different view. He thinks some electric car efficiency claims are hyped (‘between 60 and 90 per cent’ he reckons). However, for sub 150 mile journeys he thinks battery electrics have the efficiency edge over fuel cell cars, but for driving from say, London to Manchester without stopping ‘for hours to charge,’ fuel cell models still had an advantage. ‘More comfortable, but not as efficient,’ he said.

Then there’s the issue of re-fuelling hydrogen cars in the first place. Stations that do this are virtually non-existent. The UKH2 Mobility lobbying body reckons the M25 boasts five hydrogen fuel stations. Fuel cell car drivers in Swindon, Rotherham and Aberdeen have somewhere to tank up, but you can forget it anywhere else. 

For fuel cell cars to be truly usable you’d need about 400 UK-wide re-fuelling points, reckons the Petrol Retailer’s Association. Tankers would be needed to bring the hydrogen, unless on site plants were used. They exist, but cost an eye watering £1m each. 

Does that kill off hope for fuel cell passenger cars? Not quite, many truck and bus operators are looking at the technology for their vehicles, and if hydrogen powered lorries, buses and coaches became commonplace, a network of filling stations would be needed for them, which could also serve cars. 

If you want a new fuel cell car the choices are limited to either a Toyota Mirai -yours for around £55,000- or the £69,495 Hyundai Nexo. A hydrogen BMW X5 is being launched, but might not get here until the mid 2020s. Meanwhile, combined Mirai and Nexo sales currently stand at about 230, rather less than the 190,000 battery electric cars sold in Britain during 2021. 

This hasn’t stopped Jonny Goldstone from buying 65 fuel cell Mirais. Goldstone co-owns London-based Green Tomato Cars, a taxi service that uses hybrid, fuel cell and pure electric vehicles in the shape of 150 VW iD.3s, so he knows a bit about the pros and cons of fuel cell and pure electric cars. Reliability hasn’t been an issue with his Toyotas, which have covered 3m miles and counting, but how do the costs rack up?

Fuel cell works well in large vehicles such as buses

“Overall, hydrogen has a similar cost per mile to (a tank of) unleaded petrol. The cost of fast charging an electric car like the ID.3 is around 40 per cent less compared to petrol. So electric wins on that analysis. Hydrogen wins in terms of speed and range. Fast chargers give you about 80 per cent in 30 minutes, and you get well over 200 miles per full charge. The Mirai gets up to 380 miles and will re-fuel in 3-4 minutes,” he said.

Pure electric car fans like Quentin Willson point to Tesla’s cobalt-free batteries, the possibility of lithium extracted from clay, and the development of solid state batteries as developments that will make electric cars go further, be cleaner and spend less time charging, but if a viable hydrogen re-fuelling network is built, we could see battery and hydrogen technologies co-existing.

Johnny Goldstone thinks that this is still a possibility. “There isn’t a ‘best solution’ that will trump everything else,” he said. “Electric cars have made huge strides and there will be a lot more development, but I can see them and fuel cell cars running alongside each other. It’s still too early to put all our eggs in one basket.”

The Toyota Mirai isn't a big seller, but could catch on

Hydrogen as a fuel

As anyone who has ever seen those famous images of the Hindberg airship disaster will know, hydrogen burns really well. So could we get use our existing infrastructure and engines and just swap petrol for hydrogen?

In theory, yes. There have been plenty of prototypes from companies such as BMW where the fuel tank has been swapped for the sturdy tanks needed to contain the highly flammable gas at high pressure safely.

The issue is that burning hydrogen using the air from the atmosphere produces nitrogen oxides, which are a harmful pollutant which needs to be treated with emissions control equipment such as catalysts. It is possible to get a far cleaner burn by only using pure oxygen, but this involves the use of another tank and more refuelling time – and expense.

With all this taken into account, it is simply more cost effective and efficient to use a battery electric vehicle or fuel cell on new vehicles in most situations.

BMW toyed with the idea of selling cars which burned hydrogen in a conventional combustion engine