- David Hort
Are hydrogen cars any closer?
Hydrogen has long been touted as a viable alternative to petrol, diesel and electric vehicles (EVs) – even before they have really taken off. In its own way it’s the nuclear fusion of car propulsion; apparently only a matter of years away from revolutionising the industry.
Just a few years ago we had the BMW 7 Series Hydrogen zooming around streets, dripping only water from its exhaust like a leaky tap. And the Honda FCX Clarity is forever at motor shows, in danger of becoming a Tomorrow’s World curio like the nuclear-powered Ford Nucleon or any biofuel model from recent history.
Hydrogen’s USP is that – theoretically – it produces water vapour as its only by-product; assuming you can find a way to produce it in large quantities through a method that is itself economically and environmentally viable.
The potential results are something of a holy grail in the power industry: cheap energy derives from water and producing… water. No oil, no carbon, no NOx or SOx or particulates. No reliance on foreign oil from unstable climes; no energy from coal-, gas- or nuclear-fuelled power stations.
Of course, realising that potential is proving to be rather difficult, but recent developments have suggested that there may be clean, economical methods for creating hydrogen not previously available – just at a time when Honda has opened a hydrogen refuelling station. In Swindon.
With that in mind it’s time to ask, once again, whether hydrogen-powered cars are a real possibility.
How long has hydrogen fuel been around?
Hydrogen powered cars have been in the pipeline for a number of years, with Honda building the first hydrogen concept – the FCX concept – in 1999. Since then a number of manufacturers have jumped on the bandwagon and begun developing and testing their own hydrogen vehicles, with some even being released in small numbers.
Honda leads the way with the FCX Clarity saloon and has also recently opened the UK’s first public hydrogen refuelling station in Swindon.
Hyundai is at the front of the chasing pack; having recently unveiled a hydrogen-powered ix35 crossover, while BMW has also released 100 versions of a hydrogen-powered 7 Series.
How does it work?
There are two basic forms of hydrogen vehicles in development. The most common use hydrogen fuel cells to power an electric motor, while the other burns hydrogen in the engine’s combustion chamber.
Hydrogen fuel cells
A hydrogen fuel cell works in the same way as a battery; it can essentially create electricity as long as hydrogen and oxygen are being supplied.
In the simplest of terms, when oxygen and hydrogen combine in the fuel cell, they produce enough electricity to power an electric motor. The only by-products are oxygen and water vapour.
One extension of hydrogen fuel cell technology is to combine it with an electric battery to create a fuel cell electric hybrid.
Both the fuel cell and the electric battery will work together to power the electric motor; resulting in a much bigger range.
Hydrogen combustion engines
Hydrogen combustion engines replace petrol or diesel with hydrogen in such vehicles. Hydrogen is burned in the combustion chambers to power the engine as normal.
Where petrol is normally injected into the combustion chamber, hydrogen cars inject liquid hydrogen into combustion cylinders to drive the engine.
This is the type of hydrogen power used by BMW, who believe it to be a more efficient use of hydrogen than fuel cells. It also means the car should maintain similar performance figures in terms of acceleration and top speed to standard fuel models.
However the technology has been criticised because of its poor fuel consumption, with one full tank of liquid hydrogen allowing for a 124 mile range on the Hydrogen 7. The same tank could hold 45 gallons of petrol which would allow for a range of 765 miles.
Mazda has followed a similar method of propulsion with the RX-8 Hydrogen RE boasting the hydrogen internal combustion.
It has similar fuel consumption figures to the BMW of around 60 miles per full tank of hydrogen but more than 340 miles on a full tank of petrol.
Producing hydrogen
Producing hydrogen for use as a fuel for passenger cars is the major sticking point for uptake of hydrogen vehicles, with the costs prohibitive.
Hydrogen can be produced by splitting water via a process of electrolysis. The method separates the hydrogen and oxygen which are then recombined within a fuel cell to create electricity to power the car or, in terms of BMW’s hydrogen combustion engine, the hydrogen is kept separately and burnt as a fuel inside the car’s engine.
Natural gas is currently the most common source of hydrogen, but the process is energy and carbon-intensive, meaning limited scope for marketing hydrogen produced in this way as sustainable.
A group of American scientists have recently released the results of an experiment which points towards the use of bacteria that can produce electricity as it breaks down organic matter.
That electricity can be used within a fuel cell to combine split water and produce hydrogen – the researchers say that there is scope to produce hydrogen for use in cars but the technology is not currently commercially viable.
Whilst the technology remains in its infancy there is evidence to suggest that the cost of producing hydrogen fuel could drop significantly over the next few years, making hydrogen powered cars much more realistic and cost-effective on a large scale.
Why hasn’t it taken off?
At present the technology remains too expensive to be viable in volume production. It is estimated that each hydrogen vehicle produced costs between £200,000 and £1m to manufacture.
The reason hydrogen is so expensive is that vast amounts of electricity are needed to create hydrogen in the first place, as is the case with the electrolysis of water.
Until that process can be powered by renewable energy sources, and sufficient quantities created, hydrogen production is set to remain expensive and unfeasible for volume manufacturers.
The storing of hydrogen in vehicles is also a sticking point for hydrogen fuelled cars.
When stored as a gas, hydrogen must be compressed under intense pressure and then stored in special high-pressure containers. As they sound, these pieces of equipment are expensive and add to the overall cost of the vehicle.
A hydrogen gas chamber that can maintain appropriate pressure, temperatures and amounts of gas are much bigger than fuel tanks.
Hydrogen can be stored in liquid form, however it needs to be chilled and compressed and then kept at very low temperatures to prevent it and boiling. That means it’s a highly volatile substance and would again be expensive to produce and store onboard a vehicle.
Hydrogen is also much less efficient in terms of factory-to-motor than petrol, diesel of electric vehicles because it takes far more energy to create, maintain, transport and use from source to the car.
What are the advantages of hydrogen fuel?
The biggest advantage for hydrogen fuel is how clean it is. Where diesel and petrol create CO2 emissions, NOx and other pollutants, hydrogen has one by-product; water.
The advantages of a car that runs on fuel derived from water and producing only water are obvious, even if they have proved practically elusive.
Hydrogen cars should also be quicker to refuel than electric vehicles because they use a similar refuelling process to petrol and diesel stations. A pump is plugged in and hydrogen fed directly into a storage unit.
Infrastructure
Hydrogen-powered cars also face a similar problem to electric vehicles in terms of infrastructure. There is currently only one publicly accessible hydrogen fuelling station in the UK, having opened in September 2011.
Where biofuels and LPG sources could be built into existing petrol stations, liquid hydrogen fuel has to be stored in cold tanks that require burying.
In Germany, estimates for a nationwide hydrogen fuelling infrastructure stand between £870m and £1.2bn which is deemed too expensive for a technology yet to prove financially, ecologically and practically viable.
GM was less optimistic in its estimate of the cost of equipping Europe and North America, stating that as much as £16bn would be required for a sustainable hydrogen infrastructure.
EVs, hybrids and hydrogen
Hydrogen remains a distant third in this general list of alternative fuel options, with electric vehicles and petrol-electric hybrids the favoured technologies for car manufacturers due to their market readiness.
With the potential to erect charging points around the country – and plug-in electric and hybrid vehicles being chargeable at home, the latter have an advantage over hydrogen models in terms of a more easily-created infrastructure.
And while several car manufacturers have dozens of hybrid or electric vehicles currently on the market, hydrogen models remain at the prototype stage.
Hydrogen does, at least, appear to be the long-term bet as far as alternative fuels are concerned and such a potential ‘magic bullet’ solution to fuel concerns continues to attract wide-ranging funding and interest.
What cars are available?
Only a select number of manufacturers have brought working hydrogen-powered prototypes to market over the last decade, meaning you won’t be able to buy a hydrogen vehicle unless you’re one of the chosen few selected to lease a hydrogen vehicle.
There are, however, a growing number of prototypes from manufacturers that made the leap from drawing board to tarmac.
Honda FCX Clarity
Honda’s FCX Clarity is the most mainstream hydrogen car on the market but unfortunately it is only available in North America and Japan on a lease deal which costs the equivalent of £380 per month.
The reason it’s so expensive to lease is because it costs an estimated £200,000 to build.
There are currently no plans to bring it to the UK because of its expense but Honda has also pointed to a lack of infrastructure in the UK when compared to America and Japan, despite the Japanese manufacturer opening a hydrogen fuelling station.
Hyundai ix35
The ix35 is a compact crossover from the Korean manufacturer but the hydrogen version is a mere prototype.
Its future is summed up by the company’s UK managing director, Tony Whitehorn: “The ultimate goal would be to see zero-emission vehicles on UK roads within the next few years; however, the market and local infrastructure will be the real determinant of this."
BMW Hydrogen 7
Like the two previous models, the hydrogen 7 Series is a project study as opposed to a real car, available in the UK or anywhere.
Rather than a hydrogen fuel cell, the 7 Series burns hydrogen in the same way that a petrol car would burn its fuel.
BMW says it’s the world’s first ‘production-ready hydrogen vehicle’ but at the moment it remains in the testing period with 100 models on the road.