London - With hybrid and full electric cars now becoming mainstream, it may seem as though the early debate between hydrogen and battery power is over.

But batteries have considerable drawbacks. They’re heavy, they’re expensive, they require the extensive use of rare earth metals, and the production of lithium-ion batteries is itself an energy-intensive process that creates considerable emissions. Despite the progress made in EV technology, most car companies are predicting it will be a long time before batteries become dramatically cheaper or lighter than they are today.

Speaking to investors last year, Stefan Juraschek, vice president of electric-powertrain development at BMW, said the car maker needed to “walk through the valley of tears” of funding highly costly research and development in order to make significant progress on battery power.

Electric cars require energy straight out of the mains, which could come from power plants that are not using renewable technology. In Tesla’s home state of California, 60% of electricity was provided by coal and gas power stations in 2015, while only 14% came from wind and solar. China is investing more in renewables than any other nation yet derived roughly 72% of its electricity from coal power in 2014.

In a hydrogen fuel cell car (FCEV), electric motors power the wheels but the energy is supplied through a chemical reaction between hydrogen and oxygen in the fuel cell. Unlike the rare and heavy components needed to build a battery, hydrogen is the most abundant and lightest element in the known universe although it is worth noting that hydrogen drivetrains also require rare materials.

Hydrogen's two big advantages

The major advantage of hydrogen fuel cell technology is it only emits water as a byproduct and doesn’t need any additional inputs. So if the hydrogen is being generated by a sustainable source, it has the potential to deliver truly CO2-free motoring. 

The Toyota Mirai (above) is one of only three hydrogen cars (or FCEVs) available on the market in the UK today, the others being the Hyundai ix35 Fuel Cell and the Honda Clarity. Billed as the world’s first fuel cell vehicle for the mass market, the Mirai costs £66 000 (R1.22 million) and has a range of 483km. The high pressure hydrogen canisters contained within the chassis have an energy density of 1500 Wh/h.

“Refuelling time is also a key advantage of hydrogen electric drivetrains,” says Jon Hunt, who heads up Toyota’s Mirai project in the UK.

“Most FCEVs can be refuelled in three minutes, allowing for fuel forecourt dispensing, as refuelling takes a similar time to petrol and diesel.

Committing to hydrogen tech

Although the world may seem to have gone silent on hydrogen power, major energy and transportation companies recently committed to spending billions on the development of hydrogen technology every year. 

At this year’s World Economic Forum in Davos, the chief executives of 13 major multinationals convened to establish the Hydrogen Council, created with the aim of promoting and developing hydrogen fuel cell and related technologies. They will collectively spend £8.2 billion on hydrogen over the next five years. Among the companies that formed the council were BMW, Toyota, Hyundai, AngloAmerican, Shell, Total, Audi, BMW, Kawasaki, Engie, Honda and Alstom.

Toyota’s commitment to hydrogen reflects the priorities of the Japanese government, which wants to see 800 000 FCEVs on the country’s roads by 2030, requiring 900 refuelling stations. It’s part of what the government describes as our future as a “hydrogen society” and it goes well beyond powering cars.

As Hans Griemel and Naoto Okamura have written in Automotive News: “It envisions mini hydrogen plants at homes and businesses, a nationwide hydrogen distribution system coursing through the countryside, big advances in deployment and scale that would dramatically reduce vehicle and fuel prices, and the establishment of a carbon-free hydrogen manufacturing process, all in a bid to create the ultimate green-energy loop.”

Apart from the related issue of cost, a lack of expensive infrastructure required to maintain a significant hydrogen fleet remains the main reason why the cars haven’t sold in significant numbers. Hydrogen cars require access to compressed hydrogen gas, meaning a hydrogen pump would need to be installed in houses, as well as petrol stations. Hydrogen fuel cells are also currently more expensive than their battery equivalents, and just as expensive to refuel as petrol, although both these costs are likely to decrease over time.

In March, Alstom unveiled the world’s first hydrogen-powered passenger train, the Coradia iLint and last week the world’s first hydrogen-powered boat left France on a six-year journey to prove the experimental use of hydrogen in marine applications.

More than 200 years have passed since François Isaac de Rivaz built his hydrogen-powered internal combustion “De Rivaz” engine, and more than 50 years since fuel cell technology began to be touted as an alternative to fossil fuels. While the scale of global R&D means we are likely to see further innovations in hydrogen fuel cell technology, it could be years before it becomes clear whether the Japanese vision of a hydrogen society will become a reality.

The Independent

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