Why is hydrogen so dangerous as a source of energy?

Scott "Hawaii" Morrison tells us that hydrogen fuel will "transform our transport, energy, resources, and manufacturing sectors. So we can assume by "transport", he is referring to cars, vans, trucks, and possibly buses, and trains. Many car manufacturers are already producing versions of hydrogen-powered cars to sell to the public so we are entitled to consider how safe are hydrogen-fuelled cars, and equally important, how safe are any places where hydrogen is stored in tanks as fuel.

Why is your hydrogen-powered family car like a bomb on wheels?

LEFT: The liquid hydrogen and oxygen tanks on the Space Shuttle Challenger explode 73 seconds after take-off in 1968 obliterating the shuttle and killing all astronauts; RIGHT: A hydrogen-powered family car envisaged by Scott "Hawaii" Morrison for Australians will probably have to contain the same lethal liquid hydrogen tanks that destroyed Challenger in 1968.

Liquid hydrogen as rocket fuel played a major role in American space exploration including the moon landings and the space shuttle programme. NASA had to cope with the hard fact that even small amounts of liquid hydrogen can be explosive when combined with air, and that only a spark is required to ignite liquid hydrogen and produce an explosion. The extreme danger of hydrogen as fuel became apparent to the world in 1968 when one of space shuttle Challenger’s massive liquid hydrogen tanks exploded destroying the shuttle only 73 seconds after take-off and killing all astronauts.

The major source of energy using hydrogen is the hydrogen fuel cell. Hydrogen is fed into the fuel cell from a tank containing hydrogen in gaseous or liquid form. Oxygen is fed into the fuel cell in the form of the air that we breathe. A chemical reaction takes place in the cell between the hydrogen and oxygen. This reaction produces electricity and water as a by-product. The water is discharged from the cell. One fuel cell is not sufficient to power even a small car.

Oxygen gas is fed through the cathode, where it absorbs electrons to create oxygen ions. The oxygen ions then travel through the electrolyte to react with hydrogen gas at the anode. The reaction at the anode produces electricity and water as by-products.

There are only two possible ways to provide hydrogen as fuel for cars. One way is highly compressed hydrogen gas in one or more tanks inside the car. The other way is deep freezing hydrogen gas until it becomes a liquid and can be stored as liquid in a tank. To achieve and keep hydrogen in liquified form it must be reduced to and kept at a temperature below -252.87 °C by deep freezing. Yes, that is 252.87 °C below the freezing point of water!

Liquid hydrogen is a high-flammability fuel, and special handling, methods of storage, and transport need to be strictly followed in order to avoid critical incidents, including explosions of fuel. Elimination of sparks from electrical equipment, static electricity, open flames or extremely hot objects need to be employed to insure safety. These safety measures for dealing with liquid hydrogen will not only have to take place inside the inner workings of the hydrogen vehicle, but in the fueling stations, transport vehicles and other parts of manufacturing and distribution as well.

To power a vehicle by gaseous hydrogen requires massive compression inside a tank to give the vehicle reasonable driving range. It can be reasonably argued that highly compressed hydrogen in tanks inside a car effectively produces cars that are bombs on wheels. Scuba tanks used in underwater diving are universally recognised as potentially dangerous and are handled and treated with great care. These scuba tanks usually contain air compressed at a range roughly between 160 to 240 Bar. Normal atmospheric pressure of the air that we breathe is represented by 1 Bar.

Today, many car manufacturers are proposing to sell hydrogen-powered cars to the public with the hydrogen stored in highly compressed form in one or more tanks inside the cars. The highly compressed hydrogen gas commonly reaches pressures as high as 700 Bar, or 700 times normal atmospheric pressure. This massive compression of hydrogen gas inside a tank could allow a car that runs on a fuel cell battery to cover between 500 and 600 km between fill-ups.

Australians will have to make their own decisions whether to put their loved ones in hydrogen-fuelled cars that are effectively explosive bombs on wheels.

Is liquid hydrogen any safer? It produced the disintegration of the NASA Space Shuttle Challenger and killed every crew member. Unlike petrol, liquid hydrogen degrades the tanks that contain it in liquid form in a family car. It can turn the metal of the tank brittle, and consequently, render the tank more likely to disintegrate. If the liquid hydrogen rises above a temperature of -252.87 °, the resulting gas needs to be vented to prevent an explosion and kept safely away from a spark that could also cause an explosion. Apart from these very scary risks, expert care of a hydrogen-powered vehicle will be required throughout its life to keep the occupants reasonably safe.

If hydrogen-powered cars are effectively bombs on wheels, working in or living near any facility where hydrogen is stored in tanks is highly dangerous to human life.

An explosion from a hydrogen facility close to homes in North Carolina USA shows how dangerous it is for workers and nearby residents.

The explosion at this hydrogen fuel plant located close to homes in Catawba County, North Carolina, USA in 2020 damaged sixty nearby homes and has left residents living near the hydrogen facility living in fear of further explosions.

Two examples from Norway show how dangerous hydrogen can be when used as fuel for cars or stored in tanks for industrial use.

LEFT: An explosion in a hydrogen refuelling station outside Oslo in Norway produced a blast so powerful that it triggered protective airbags in passing cars; RIGHT: A leak from one of a number of large high-pressure hydrogen fuel tanks produced an explosion that caused massive damage to the installation.

This hydrogen fuel tank explosion in Gangneung, South Korea, killed two and injured six.


German carmakers Mercedes Benz and Volkswagen have recognised the grave risks associated with use of hydrogen as fuel for cars and have turned to electric vehicles. It has been reported in the European press that BMW's interest in hydrogen-powered cars has cooled to only minimal interest. Toyota and Hyundai are still pushing their hydrogen-powered cars despite low buyer interest probably aggravated by frightening explosions across the world associated with use of hydrogen as fuel.

This hydrogen proposal has the smell of a pre-election political "snow job" from a politician whom many Australians probably feel could not be trusted to sell them a reliable used car. Opposition Leader Anthony Albanese, National's Leader Barnaby Joyce, and smaller but significant political parties are unlikely to be fooled by Morrison's "pie in the sky" hydrogen proposal.