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 considerable 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 per cent of electricity was provided by coal and gas power stations in 2015, while only 14 per cent came from wind and solar. China is investing more in renewables than any other nation and has derived roughly 72 per cent of its electricity from coal power in 2014.

In a hydrogen fuel cell car (FCEV), electric motors power the wheels but the electrical energy is supplied through a chemical reaction that takes place 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.

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. To prove this point, Toyota introduced a hydrogen timing car to the IAAF World Championships last month, and compared its water output to that of the participants.

The car maker said: “Studies of marathon winners have found that they typically lose between three and 4kg in weight over the 26 miles of a race, body mass that is principally lost through sweat. Driving the same distance, the Toyota Mirai’s fuel cell will produce just over 3kg of water.”

The Toyota Mirai, billed as the world’s first fuel cell vehicle for the mass market (Rex)

The Toyota Mirai 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 and has a range of 300 miles. The high pressure hydrogen canisters contained within the chassis have an energy density of 1,500 Wh/l, about three times denser than today’s EV batteries, meaning greater range for the space given over to fuel storage.

“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. Even with fast chargers, stopping on a forecourt for 30 minutes is impractical and so charging (for passenger cars) is likely to be at home, with limited range.”

Demonstrating its very latest fuel cell developments, Hyundai unveiled a concept hydrogen SUV earlier this year, with a range of 500 miles, a 20 per cent improvement on the ix35. Other concepts have been developed by Mercedes, BMW and Nissan, among others.

Although the world may seem to have gone silent on hydrogen power, our 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 CEOs from 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 £8.2bn 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.

The new group said large businesses had a major role to play in securing a more sustainable future and committed to: “Accelerate their significant investment in the development and commercialisation of the hydrogen and fuel cell sectors ... Encourage key stakeholders to increase their backing of hydrogen as part of the future energy mix with appropriate policies and supporting schemes.”

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 Abe 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.

“In chasing this so-called hydrogen society, the government in Tokyo is embarking on a revolution – potentially as significant as the shift from horses and coal to motors and petroleum more than century ago.”

For its part, the US government has put $1.5bn into hydrogen since President Bush’s Hydrogen Fuel Initiative began in 2005.

In the first half of this year around 1,600 hydrogen cars were sold or leased worldwide. Of these, 1,000 were registered in California. Alicia Moore, of Hydrogen Fuel News, says there are number of reasons why the cars have taken off in the Golden State, apart from being one of the few US states where the cars are widely available.

She said: “One of the reasons why fuel cell vehicles have found modest success in California is because of the state’s efforts to build a comprehensive hydrogen infrastructure. During the first half of this year, 27 new hydrogen stations were commissioned.

“Once completed, the state will have more than 250 hydrogen fuel stations ready to support fuel cell vehicles. The state government is also offering financial incentives for those interested in fuel cell vehicles, which have been welcomed by consumers.”

By comparison, the UK has 13 operational hydrogen refuelling plants, some of which are used solely by universities for research purposes. But the outlook is looking better for the early adopters of hydrogen tech. In March this year, the UK Government announced £23 million would be used to accelerate the uptake of hydrogen cars and the expansion of the country’s hydrogen refuelling stations, with around 65 expected by 2020.

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.

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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.

VW’s commissioner for electric drive systems, Rudolf Krebs, has said we’re unlikely to see hydrogen cars on our roads in significant numbers before 2020, and poured cold water on the idea that they represent major efficiencies compared to their lithium-ion competitors.

“We still have the problem that hydrogen mobility only makes sense if you use green energy – you have to use green electricity, then convert it from electric to hydrogen, during which you lose about 40 per cent of the initial energy,” he said at the LA Motor Show in 2013.

“Then you have to compress the hydrogen to 700 bar to store it in the vehicle, which costs you further efficiency. After that, you have to convert the hydrogen back to electricity through the vehicle’s fuel cell, which brings another efficiency loss. In the end, from your original 100 per cent electric energy, you end up with between 30 and 40 per cent efficiency.”

It’s a point also made my Tesla’s Elon Musk, who has described FCEVs as “extremely silly” and “incredibly dumb”.

“If you took a solar panel and used that to just charge a battery pack directly, compared to split water, take hydrogen, dump oxygen, compress hydrogen, it is about half the efficiency.”

Jon Hunt, Toyota UK’s Mirai project lead tells me: “A key advantage of switching to hydrogen as an energy carrier is that hydrogen can be produced from surplus energy, coupled to any zero emission renewable source on or off the grid and stored indefinitely until needed.

Alstom’s hydrogen-powered passenger train, a world first (Wikimedia Commons)

“Conversion efficiency is desirable but less important when the energy is surplus. Solar panels can’t provide energy in the dark, nor wind turbines when it is calm, so it is not possible to rely on these to be available to charge batteries. Batteries need to be charged on demand and require the grid to provide power immediately in the locality. Any significant increase in battery electric vehicles will require considerable investment in energy production and distribution.”

If hydrogen does become popular in the domestic market, it’s likely that the commercial sector will pick up the technology first. There are already hydrogen buses operating around the world and, as of last month, Amazon and Walmart started switching to hydrogen forklift trucks at their warehouses.

“Increasing the range of a FCEV is achieved by making the hydrogen tank bigger which has only a small effect on the weight,” says Jon Hunt.

“The result is that hydrogen vehicles have a much longer range and can also be easily configured for heavy duty vehicles such as buses and haulage vehicles.”

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. Described as a “floating smart grid system”, the Energy Observer uses a mix of solar, wind and wave energy to create its own hydrogen on board.