The great hydrogen revolution gathers pace

Clean power: Hydrogen can be produced from water by using renewable energy to power electrolysis. © Alamy

Are we on the cusp of a hydrogen revolution? A new material, similar to a bath sponge, could be the key to making the most abundant element in the world the green fuel of the future.

A BBC journalist drives for an hour in a silent car, parks, and makes a cup of tea – from the exhaust pipe.

This is, of course, no ordinary pollution-releasing car. It is a car powered entirely by hydrogen, whose only waste product is hot water.

As countries scramble to meet the IPCC targets of 1.5 degrees maximum global warming, switching to clean energy sources for cars and other vehicles could be an environmental game-changer.

Hydrogen-fuelled cars may already exist, but two major roadblocks have prevented hydrogen from becoming a mainstream fuel.

First, lack of infrastructure: there are only 11 refuelling stations in the UK, for example. Second, since pure hydrogen does not occur naturally, it has to be produced by splitting water, which requires energy – thereby, potentially reducing its green benefits.

The chemical properties of hydrogen exacerbate these problems. The gas is so light that for a car to carry enough hydrogen without an impossibly large fuel tank, the gas must be compressed to 300 times more pressure than a normal tyre.

Producing hydrogen at these pressures is risky – especially for a notoriously explosive gas. It takes more energy and requires the fuel tank to be carefully engineered for safety. This pushes car prices up and makes it harder to encourage more people to buy these cars.

Without customers, industries are reluctant to build more fuel pumps, which then reduces the appeal of buying a hydrogen car.

However, a newly developed material could unlock hydrogen’s potential.

“It is like a bath sponge, but with very ordered cavities,” said US-based Professor Omar Farha, who led the research. Just one gram of this highly porous, metal-organic framework has the same surface area as a football pitch, allowing it to store large volumes of hydrogen at a much lower pressure and cost.

This could bring down the cost of hydrogen cars and improve their performance, making the fuel a viable mainstream solution.

Scientists are pointing out that more research is required to get this material ready to be of practical use. They say that more than 100 years went by between the invention of the hydrogen fuel cell and its first actual use.

So, are we on the cusp of a hydrogen revolution?

Future perfect?

Yes. As well as not producing any CO2, the resulting gas doesn’t contribute to air pollution when it’s burned. Advocates believe it could be the answer to one of the most difficult sectors to decarbonise – heavy transport, such as lorries and buses.

No. Hydrogen will never really take off. Elon Musk, whose electric cars are the biggest rival to hydrogen-powered models, notoriously labelled hydrogen fuel cells “fool cells”. There is a long way to go before these vehicles enter the mainstream.

You Decide

  1. What is the most important new technology invented in your lifetime?
  2. Should the government introduce subsidies to support the development of hydrogen-powered vehicles?

Activities

  1. Create a simulation of different types of porous rock. Get two equal-size small containers and fill each with differently sized dried food, such as lentils in one and butter beans in the other. Fill both with water. Does one take more water than the other? Why?
  2. Imagine hydrogen goes on to revolutionise the energy sector. No vehicles use natural resources anymore, or emit any pollution. Write a one-page, sci-fi story set in this time. What would it be like?

Some People Say...

“Hydrogen is the most abundant element in the Universe and offers the game-changing promise of clean power on a mass scale.”

Paul Hackett, energy writer

What do you think?

Q & A

What do we know?
Hydrogen has the potential to be an environmentally game-changing, clean fuel. Several countries have already invested in hydrogen-powered trucks, coaches, ships, and trains, showing their government’s interest in pursuing hydrogen as a way to meet emission reduction targets. Countries in Asia are leading the way in implementing hydrogen fuel pumps and hydrogen-powered car manufacturing. Drone tests even suggest that hydrogen-powered air travel may soon be possible.
What do we not know?
Whether hydrogen will actually receive the support it needs to get off the ground. In order to become widely adopted, it needs more funding and more scientific development – which history suggests can take a lot longer than expected. It also needs government support and investment from industry, which usually includes a complex assessment of the risk versus potential to make a profit.

Word Watch

Hydrogen
The first element in the periodic table, and the most common element in the Universe. Stars are mostly made up of hydrogen.
IPCC
The Intergovernmental Panel on Climate Change is a global collaboration of top climate scientists to produce annual reports on global warming.
Exacerbate
To make a bad situation even worse.
Porous
The amount of empty space inside an object. A rock with a lot of air holes (like a pumice stone) is said to be highly porous. The more porous a material is, the more it can absorb other substances.
Metal-organic
A class of compounds consisting of metal ions, or clusters, co-ordinated to organic ligands to form one-, two-, or three-dimensional structures.
Viable
Capable of working successfully.
Fuel cell
Like a battery, this is the device that converts hydrogen into electricity inside a hydrogen-powered vehicle.
Decarbonise
To reduce the amount of carbon.

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