A decade ago, it seemed like there were two potential contenders to replace fossil fuel for personal transportation – electricity and hydrogen. The hydrogen option had a lot going for it. You could fill your car up just like fossil fuel, but instead of noxious gases coming out of the tailpipe, the exhaust would just be pure water vapour. It sounded like the perfect step forward towards a greener future where we could carry on using our vehicles as before, only without the environmental downsides. Compared to waiting around for an EV’s battery to recharge, hydrogen appeared to be the much more convenient option.
Why hasn’t hyrdogen delivered on its promise of being the green car fuel of the future?
But ten years later, it’s very clear that battery electric vehicles (BEVs) are dominating the shift towards more environmentally friendly transport instead. By the end of 2019, only 7,500 hydrogen cars had been sold around the world. But by the end of 2018, there were already over 5 million plug-in electric vehicles (PEVs) globally, and sales have been accelerating considerably since then. The BEV segment within this has never been less than 55% and is now more like 75%. In the UK, according to the Society of Motor Manufacturers and Traders, BEVs were up to 4.3% of the overall car market year-on-year by May 2020, representing a 131.8% increase since 2019. The BEV is starting to challenge fossil fuel cars, and their fuel cell alternatives are getting nowhere.
The new Toyota Mirai, a hydrogen fuel cell electric vehicle, on display at the 2019 Los Angeles Auto … [+]
Toyota was one company that truly believed in the hydrogen future, and produced the very credible FCV-R concept in 2011 that developed into the Mirai, which became commercially available in 2015. A second generation will be released in 2021. Honda has also produced a couple of fuel cell vehicles, the Clarity Fuel Cell and FCX Clarity. Hyundai has the Tucson Fuel Cell. So there are some choices available, and these vehicles are all quite viable for everyday usage, with the Mirai offering a range of 312 miles on a tank, and the Honda Clarity Fuel Cell managing a very healthy 366 miles.
So why haven’t hydrogen fuel cell vehicles (FCVs) taken off in the same way as BEVs, considering their convenience? June 2019 could be the month that scrawled the writing on the wall. No sooner had a chemical plant producing hyrdogen in Santa Clara exploded, leaving FCV users in California short of fuel, but just a few days later a refuelling station in Sandvika, Norway also went up in flames. This really brought home the truth that hydrogen can be a dangerously explosive gas – as if we didn’t know it already. I haven’t heard of any cases of the cars themselves detonating, and the fuel tanks are now Kevlar-lined to protect against this explosive possibility. But it was hardly a confidence-inspiring series of events.
We’ve known that hydrogen can be a dangerous gas for transportation since the Hindenberg disaster… … [+]
However, the safety concerns are not the main reason why hydrogen is a far inferior option for personal transportation than BEVs. If one of your main goals is to save the planet, BEVs are considerably more energy efficient than FCVs, when you take into account the whole series of steps between power generation and propulsion. With a BEV, once the electricity is generated – hopefully from a renewable source – the supply of this to your vehicle charging location loses about 5%. The charging and discharging of the battery then lose another 10%. Finally, the motor wastes another 5% driving the vehicle. That makes for a total loss of 20%.
With a hydrogen fuel cell, however, you first have to convert the electricity to hydrogen via electrolysis, which is only 75% efficient. Then the gas has to be compressed, chilled and transported, which loses another 10%. The fuel cell process of converting hydrogen back to electricity is only 60% efficient, after which you have the same 5% loss from driving the vehicle motor as for a BEV. The grand total is a 62% loss – more than three times as much. Or, to put it another way, for every kW of electricity supply, you get 800W for a BEV, but only 380W for an FCV – less than half as much. That’s a huge inefficiency if you’re hoping for a greener future, and doesn’t even take into account the fact that 95% of hydrogen is currently generated from fossil fuel sources.
Despite its inefficiences, hydrogen can still make sense as a fuel type for large commercial … [+]
Nevertheless, hydrogen still has niches where its main strengths – lightness and quick refuelling – give it a clear advantage. While you can fit your personal driving lifestyle around strategic battery charging stops, this is not ideal for a commercial vehicle that needs to run for very long periods and distances with only short waits to refuel. The weight of batteries for eight hours of continual usage would also be prohibitive in a train, for example. So, for industrial vehicles, hydrogen seems like a viable option, despite the inefficiency. Nevertheless, in the UK, there were only ten hydrogen-powered buses in service in March 2019, alongside 155 electric ones (with more arriving) and 3,669 hybrid ones. But a hydrogen double-decker is also coming into service in London, with hydrogen diggers and trains also already in use. Stock market darling Nikola Motor is working on hydrogen semi-trailer trucks alongside electric and hybrid variants.
But for personal car users, it’s no contest. Hydrogen evangelists are still arguing that FCVs are the future of personal transport and the technology will take off in 2020. It’s likely that FCV energy supply-chain efficiency will be improved over time and more renewable energy sources used in hydrogen production. However, considering the number of BEVs already on the road, FCVs have lost this battle already and will never catch up. A BEV is a viable form of personal transportation right now in most developed Western nations. There are lots of options with over 200 miles of range, and Tesla
