New e-fuels could help save the planet (and your car) but at a hidden cost

The likes of Porsche and Ferrari are banking on synthetic fuel to ensure their cars are exempt from the EU ban on the sale of new combustion engine vehicles by 2035.

Synthetic fuel – or electrofuel (e-fuel) – is a form of petrol made using hydrogen from water and carbon from air. The problem is the electricity that’s required to extract these elements. Nevertheless, companies are already producing e-fuel on a small scale, including some in the UK.

So will we see e-fuel in petrol stations soon and can we, and the planet, afford to use it? We spoke to Professor Patricia Thornley, Director of the Energy and Bioproducts Research Institute (EBRI) at Aston University, to find out.

What are e-fuels?

E-fuels are synthetic fuels. We create them from the building blocks of carbon dioxide (CO₂) and hydrogen. You can use electrolysis to produce hydrogen and you can pull the CO₂ out of the atmosphere by direct air capture.

Combining these produces a hydrocarbon fuel. If you get different mixes of these molecules, then that provides you with different fuels for different purposes: lighter molecules are suitable for, say, an aircraft’s ignition fuel, while you’ll need heavier molecules for car or marine engines.

How are they different from biofuel?

With biofuels (for example, ethanol and biodiesel) you’re growing material that contains carbon, hydrogen and oxygen, and trying to convert it into a liquid or gas that you can use.

In many ways, that pathway is the same with e-fuels but it’s different in that biofuel needs land.

The main advantage of e-fuel is that you’re not using plants but the disadvantage is that you’re using more energy and this energy still has to come from somewhere.

How does e-fuel help to cut down carbon emissions?

If we were to use e-fuel in today’s car engines, the carbon emissions that come out of the back of the vehicle will be the same in terms of the amount of CO₂ that is, literally, emitted into the atmosphere.

But that’s not all we need to think about when we think about carbon. Because if the carbon in the fuel has come from a renewable source – if, for example, it has recently been extracted from the atmosphere – then we’re recirculating it back again.

We don’t need to worry that we’ve created a new carbon burden in the atmosphere as it’s the perfect circle: those carbon atoms that were in the air have been sucked out by direct air capture, turned into a fuel and then re-released.

It’s the same with biofuels – they both give you a low-carbon fuel that can actually help us with tackling climate change.

How soon could e-fuels be available?

We’re not yet at the stage where we’re producing large enough quantities of e-fuels to be able to roll them out commercially.

Realistically, that won’t happen until we have an appropriate policy measure in place.

Would petrol stations need to change to accommodate e-fuels?

No. In the first place, e-fuel mimics existing fuel so we can operate in the existing fuelling infrastructure.

Any changes we’d need would be ‘upstream’ [at points earlier in fuel production process]: if you want significant amounts of e-fuel, then you need to have more renewable electricity in the place where you’re going to produce the fuel.

The electrical infrastructure would be the thing that has to change if we had a massive increase in e-fuel production in the UK. But you would also need electrolysis plants [where water is separated] to produce hydrogen.

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How much would e-fuel cost?

It would currently be much more expensive than other fuels. Because this method of obtaining fuel from a hydrocarbon [an organic compound consisting of hydrogen and carbon] uses electricity – and that process requires electrolysis units, which cost a lot.

To keep the cost down, we can use solar energy to do the electrolysis. Sunlight is free but we still need to get the cost of the solar panels down.

Until we reduce the cost of these units, we won’t be able to produce much hydrogen from electrolysis.

What are the hidden costs?

It’s the life cycle cost that we need to be careful about. Electrolysis units use a fair amount of rare earth metals, or what we call ‘critical minerals’. We need to be sure that if we want to build lots of these units, then we have enough critical minerals for that to still be sustainable.

That’s what makes the production of the electrolysis units, and the cost of these fuels, expensive. And then we have to combine the hydrogen and carbon dioxide via catalysts [using substances to increase the rate of the chemical reaction], which use metals too.

All the way along this production chain, we’re using Earth’s resources. If we use them in a moderate way that’s fine but if we get down to limited minerals that’s a problem.

Firstly, they’re expensive. Secondly, they’re often in parts of the world that are geopolitically unstable. And thirdly, we could be depleting Earth’s natural resources to the extent that it becomes unsustainable.

And there are also social factors to consider in the countries where these are extracted, such as mining conditions. Importantly, we need to make sure this is completely responsible.

E-fuels are a good idea but we need to look at the consequences of their life cycle and the ability of our planet to sustainably supply the metals and materials needed.

Are e-fuels safe?

Absolutely. We all get on aeroplanes and we trust them! There’s a lot of fear around the word ‘hydrogen’ – people think of the Hindenburg airship disaster.

But we’ve come a long way and the use of hydrogen is common in industrial plants globally. Of course, we must put the appropriate health and safety procedures in place but we know how to and are able to do it.