Is going electric the only viable alternative when it comes to sustainable personal transport? Supporters of hydrogen would say that it is the only fuel that would enable the complete decarbonisation of the road transport sector but others say it is far from the Holy Grail of truly environmentally-friendly motoring.
A recent White Paper from Hydrogen Mobility Ireland (HMI), a multistakeholder industry lobby group, estimated that the deployment of hydrogen across transport in Ireland could result in a not-insignificant 2.6 per cent fall in carbon emissions by 2030.
HMI says using hydrogen to power vehicles results in no direct emissions of greenhouse gases or any local pollutant emissions; the group also maintains that the gas can be used as a fuel by most vehicle types, including small cars, as well as trucks, ferries and trains.
Ireland recently opened a public consultation on the development of a national hydrogen strategy but we lag behind other European countries such as France, Germany and Portugal, who have already begun to invest in hydrogen-production projects. According to HMI, an investment proportional to Ireland’s size and commuter population could see 6,000 hydrogen-fuelled vehicles on the road by 2030.
Hydrogen will be a really important fuel when it comes to decarbonising certain parts of our economy, but the consensus view is that this will be in the ‘hard to abate’ sectors
While hydrogen will eventually play a role in sustainable transport, this comes with important caveats, says Fergus Sharkey, head of business supports and transport with the Sustainable Energy Authority of Ireland (SEAI). Sharkey says that while there is a long list of pros and cons associated with hydrogen as a potential fuel, the “conventional wisdom” is that its use in our private cars just doesn’t make sense due to the simple physics associated with its production and combustion.
“Most of the people involved in energy would argue strongly that hydrogen is not an effective solution for cars and small vehicles,” he says.
Green hydrogen is made from renewable electricity, while blue hydrogen is made from natural gas, but both undergo the same process in its conversion to fuel. “You have to produce it and then store it and transport it ... and then you have to put it into the vehicle and burn it back to electricity,” Sharkey explains. This process is highly inefficient, he says, losing 70 per cent of the energy throughout. “This means it would be relatively inefficient and potentially quite expensive to pursue a hydrogen approach to private vehicles.”
If bigger economies such as the US took a massive step towards hydrogen as a fuel for private vehicles, they would stimulate a big shift
Where hydrogen may be of use, he suggests, is in forms of transport where battery-powered electric vehicles will not be an option for practical reasons, such as aviation, or vehicles that carry heavy loads and travel long distances. “Hydrogen will be a really important fuel when it comes to decarbonising certain parts of our economy, but the consensus view is that this will be in the ‘hard to abate’ sectors, such as aviation and heavy industry.”
There’s nothing “magic” about hydrogen, Sharkey admits. “It’s simply an energy vector, it stores energy.”
He notes that the vast majority of car manufacturers have chosen to focus instead on electric vehicles as they move away from petrol and diesel-fuelled cars. Toyota, however, is an exception, having developed a hydrogen fuel cell electric vehicle called the “Mirai”. It also recently announced plans to work with BMW on a range of cars with hydrogen fuel cells as an alternative to the more popular battery-powered electric vehicles.
Sharkey points out that there are millions of EVs on the world’s road compared with just “thousands” of hydrogen fuel cell cars. And if the technology is still in its relative infancy, the necessary infrastructure is just a twinkle in someone’s eye. EVs benefit from the fact that electricity is everywhere; to move to a hydrogen transport system an entirely new energy production and distribution system would need to be developed, Sharkey says.
He also points out the inherent risks involved with the production of hydrogen given that it is produced from natural gas and other fossil fuels. “If this is not done in the right way it could contribute to global warming.”
The economics of it also don’t stack up against EVs. “It will be more expensive than electricity because you are producing it from electricity at less than 100 per cent efficiency.”
It’s not all bad when it comes to hydrogen, however. Sharkey says refuelling would be similar to our current trips to the garage forecourt, taking mere minutes compared to an average of 10 hours for an EV (albeit, a fast charger takes 15-30 minutes), and their range tends to be much longer, meaning “range anxiety” isn’t as big of an issue. And while their manufacture has a larger emissions footprint, it is believed that hydrogen fuel cell vehicles offset this within about 15,000km or roughly one-tenth of the lifespan of the car.
Indeed, Sharkey is keen not to write hydrogen fuel cell cars off altogether; the process could yet become more efficient, he says. “And if bigger economies such as the US took a massive step towards hydrogen as a fuel for private vehicles, they would stimulate a big shift.”