A hydrogen-powered car is on display at the IAA in Germany.
Musk has expressed his opinions about hydrogen and hydrogen fuel cells before.
The billionaire and electric vehicle magnate described hydrogen fuel cells as silly a few years ago when the subject came up during a discussion with reporters.
It is difficult to make hydrogen and store it in a car. The best-case hydrogen fuel cell doesn't win against the current case batteries so it doesn't make sense
In the next few years, that will become apparent. There is no reason for us to have this debate, I don't know what else to say, my piece on this will be obvious as time goes by, I don't know what else to say."
In the time since those comments, Musk's views have not changed. In July of 2020, he added thathydrogen fool sells make no sense.
First things first, what underpins the tech Musk seems so skeptical of?
Hydrogen fuel cell vehicles are similar to electric vehicles in that they use an electric motor instead of an internal combustion engine to power the wheels, according to the U.S. Environmental Protection Agency.
Electric vehicles have batteries that need to be charged by plugging them into a charging point. Fuel cell vehicles use hydrogen gas and the EPA says they can generate electricity onboard.
Fuel cells mix hydrogen gas from a tank with oxygen to produce electricity.
A fuel cell electric vehicle emits only water vapor and warm air, according to the U.S. Department of Energy.
There are a lot of views.
Musk is not the only one who is unconvinced about the use of hydrogen in cars.
Herbert Diess, the CEO of Volkswagen Group, weighed in on the subject in February of this year.
He said it was time for politicians to accept science. Green hydrogen shouldn't end up in cars. It's too expensive, inefficient, slow and difficult to transport. hydrogen cars are not in sight.
Major companies with huge influence and reach have two high-profile figures at the helm, Musk and Diess. They say what they say carries weight. Their views aren't shared by everyone in the autos sector
Smaller manufacturers such as Riversimple are also working on hydrogen-powered cars, which are being produced by firms such as Toyota andHyundai.
In June, the BMW Group said it had started to test vehicles that use a hydrogen fuel cell drivetrain, with the company describing hydrogen fuel cell tech as having the long term potential to supplement internal combustion engines, plug-in hybrid systems and battery-electric vehicles.
Riversimple won't sell its cars, but it will offer them on a subscription service instead, which is something some see potential in.
A Toyota spokesman told CNBC that fuel cell cars will play a part in decarbonizing transport.
They said that when the refueling infrastructure expands, they will offer a convenient alternative form of electric transport over a fully electric BEV.
Hydrogen was seen as an alternative to fossil fuels in all manner of settings, including heating, lighting, haulage, mass transit and heavy industry.
The range of hydrogen applications will increase, enabling cheaper, more efficient power supply and we will increasingly see hydrogen powered cars, buses, trains and trucks.
The Fuel Cell and Hydrogen Energy Association sent a statement to CNBC.
The FCHEA said fuel cell electric vehicles and hydrogen energy offered customers a zero-emission option with performance they expect and no change to daily routines.
There was a huge opportunity for fuel cell electric cars and fuel cell-powered material handling vehicles according to the FCHEA.
Medium- and heavy-duty delivery vans, trucks, buses, trains, and planes have a significant opportunity because of the limitations of battery weight and recharging for long haul trucking.
As governments around the world try to develop low and zero emission transportation systems, the idea of using hydrogen fuel cells in larger vehicles is starting to be explored by a broad range of companies.
The CEO of Daimler Truck was asked about the debate between battery-electric and hydrogen fuel cells. Martin Daum argued that balance was important.
He explained how different technologies would be appropriate in different scenarios.
If you go to a city delivery where you need less energy, you can charge in a depot overnight, which is battery electric.
You need something which you can transport better and where you can refuel better when you are on the road, and that is ultimately H2.
I think it is too risky for a company of our size to go with just one technology.
Versatility.
The idea that fuel cells could eventually find a home in heavier forms of transport, such as ferrying people from one destination to another, is touched upon in the comments by Daum.
He is not the only one taking this view. The Coradia iLint is the world's first passenger train powered by a hydrogen fuel cell.
The project to operate hydrogen-electric flights between London and Rotterdam was announced in October, with the hope that it will take to the skies in 2024.
Last year, a major player in the construction sector said that it had developed an excavator that was powered by a hydrogen fuel cell.
The company said that the vehicle had been tested for over a year and that the only emission from the exhaust is water.
There are challenges.
There is a sense of excitement about the use of hydrogen fuel cell technology in a variety of applications, but the path to mass deployment may not be easy.
Honda stopped production of its Clarity plug-in hybrid and fuel cell models earlier this year, although the company made a point of saying that fuel cell electric vehicles would play a key role in their zero-emissions strategy.
There are a number of challenges cited by the U.S. government. The range of these is from the reliability of fuel cells to the cost of a car.
It says that the current infrastructure for producing and getting hydrogen to consumers can't support widespread adoption of FCVs.
In February 2020, a campaign group called Transport and Environment hammered home how much competition hydrogen would face in the transportation sector.
T&E pointed out that green hydrogen, which is produced using renewable fuels, wouldn't have to compete with grey and blue hydrogen, which are produced using fossil fuels. T&E said that it will compete with petrol, diesel, marine fuel oil, and of course, electricity.
Hydrogen will face an uphill struggle because of it's lower efficiency and higher fuel costs.
The International Energy Agency says that it will be a huge task to bridge the gap between battery electric and fuel cell vehicles.
Fuel cell electric vehicles are three orders of magnitude lower than EV's as hydrogen refuelling stations are not widely available and unlike EV's can't be charged at home.
The race to dominate the low and zero emission future of transportation is underway.
The road to success is never a straight one, but the battery electric vehicles are in a strong position with firms such asTesla leading the charge. This is where to watch.
