Can e-fuels save the combustion engine?

Major carmakers investing in innovative tech, but do e-fuels come at too high an energy price?

If – and it’s a big if – e-fuel production can be ramped up, using only renewable energy, then maybe there’s something in this. File photograph: Daniel Leal-Olivas/AFP via Getty

For more than a decade, there has been a heavy weight resting on the consciences of all car enthusiasts. That is the knowledge that for every kilometre driven, for every turn of the wheel, we’re contributing to the global disaster that is climate change. That weight, that pressure, has grown stronger every year.

Now we can see a way out, a way to take the weight – most of it anyway – off. By switching to electric cars, which are not environmentally perfect by any means, but which are far, far better for the planet than burning dead dinosaurs in a petrol or diesel engine.

To escape our guilty consciences, though, we must sacrifice something: the spine-tingling noises that come from the great petrol-powered engine. The rumble of a Mustang V8. The gnash and thrash of a Porsche flat-six. The ungodly scream of a Ferrari V12.

Or do we? Is there a get-out clause here? Is there a way of keeping liquid-fuelled engines on the go without damaging the environment? Well, possibly.


Hydrocarbon fuel

There is a process by which a liquid hydrocarbon fuel – a so-called e-fuel – can be made, which takes carbon dioxide from the atmosphere, and combines it with artificially-made hydrogen to form a hydrocarbon – the building block of a fuel. Such e-fuels have hit the headlines recently as the likes of Porsche, Siemens and Mazda have all invested in projects that seek to mass-produce such fuels.

Porsche has plans to start making e-fuels in bulk next year, but the German sports car maker – which already has one all-electric model, the Taycan, on sale – says it's not backing away from electric investment. "Electromobility is a top priority at Porsche," said its chief executive, Oliver Blume.

“E-fuels for cars are a worthwhile complement to that – if they’re produced in parts of the world where a surplus of sustainable energy is available. They are an additional element on the road to decarbonisation. Their advantages lie in their ease of application: e-fuels can be used in combustion engines and plug-in hybrids, and can make use of the existing network of filling stations. By using them, we can make a further contribution toward protecting the climate.”

Together with a fellow giant of German technology and engineering, Siemens, Porsche has invested in a project in Chile, which uses wind-powered electricity to extract hydrogen from water, and combine it with carbon from the air, to produce e-fuel. The plan is for Porsche to start using e-fuel made by the Chilean project in the cars at its network of high-performance driver-training schools. There has also been noise in the background that if Formula One commits to using e-fuels in its cars, both Porsche and Audi could consider either supplying engines, or entering works teams.

Renewable racing fuel

Indeed, Porsche will this year attempt to prove the efficacy of its e-fuels by running its Porsche Supercup racing cars (based on road-going 911 sports cars) on its new low-carbon brews. Porsche and Esso reckon that this new “renewable racing fuel”, which contains a mix of biofuel and the new e-fuel, can score a reduction in CO2 emissions of about 85 per cent compared with regular pump petrol, although that has not been independently verified. Apart from the fact that e-fuel is made by taking carbon out of the atmosphere, there’s also the fact that e-fuels are chemically simpler than petrol, so have a cleaner burn.

For the 2021 Porsche Supercup, the cars will be running on Esso biofuel. For 2022, though, Porsche plans to start introducing the new high-tech e-fuel, and is preparing to make some 130,000 litres of the stuff for the series.

Mazda, too, is getting in on the act, joining the “e-fuel alliance” – “which brings together organisations and interested parties that support the goal of establishing and promoting CO2-neutral e-fuels and hydrogen as a credible and real contributor to reducing emissions in the transport sector.”

"We believe that with the necessary investment, CO2-neutral e-fuels and hydrogen will make a credible and real contribution to emissions reduction – not only for newly registered cars but for the current fleet," said Wojciech Halarewicz, Mazda Europe's vice-president for public affairs. "This would open up a second and faster route to achieving climate neutrality in transport, hand-in-hand with continued electrification. As the EU will review its regulation on CO2 standards for cars and vans later this year, this is the chance to make sure the new legislation enables both electric vehicles and vehicles running on CO2-neutral fuels to contribute to car manufacturers' emissions reduction efforts."

Oppressive regimes

The act of turning a mixture of gaseous hydrogen and carbon into a liquid fuel is known as the Fischer-Tropsch process and, as with so many innovations, it's not new – it was first developed by Franz Fischer and Hans Tropsch at the Kaiser Wilhelm Institut fur Kohlenforschung in Mulheim an der Ruhr, Germany, in 1925. The Nazis used it to create fuel from coal when Allied bombing cut off oil supplies, and the apartheid regime in South Africa turned to it when global embargoes meant oil imports were curtailed.

Oppressive regimes aside, the idea sounds like a golden one. By making fuel from air (more or less) we can keep the nicest and sweetest of the petrol engines going, and going cleanly, while more ordinary cars switch to petrol power. There is, though, almost inevitably, a catch.

E-fuels will almost certainly become a serious global power source in the next few years, but campaigners say that it's a waste of time, investment and energy using them in cars, when really they're needed elsewhere. "E-fuels are absolutely not worth the effort and cost, and are just an expensive sideshow pushed by oil and gas, and some carmakers, to save the internal combustion engine," Alex Keynes from environmental think-tank Transport & Environment (T&E) told The Irish Times. "The main reason is that they are inefficient and expensive and so shouldn't be wasted in cars when we need them for ships and planes, and where a much better alternative for cars already exists in the form of batteries."

Energy waste

According to T&E’s research, there’s also a huge wastage of energy in the process of turning hydrogen and carbon gases into liquid fuels. The numbersshow that taking renewable electricity (such as wind-power or solar) and putting it directly into a car’s battery, results in a total energy efficiency of 77 per cent – in other words, 77 per cent of the initial energy input is what’s making the wheels turn. For e-fuels, it’s just 20 per cent for diesel and 16 per cent for petrol.

Others argue that investing in e-fuels is a waste because we already have a perfectly good eco-friendly liquid fuel in the form of biofuels. "The whole thing is so expensive, so even though hydrogen and CO2 are abundant, there are real costs associated with distributing and stocking them, and electricity is not free and neither is building a factory," James Cogan, government affairs adviser with the ClonBio Group told The Irish Times.

“If someone gave you an e-fuel factory for free and the raw materials free and the electricity free, you would turn around and sell them all immediately because commercially you’d make more money selling them off than making e-fuel and trying to sell it. Ethanol, biofuel, is the cheapest and easiest way of cutting emissions in transport right now, in the actual fleet of cars on the actual roads today. That’s why it’s so successful.

“For anyone who takes the time to look at the sustainability and lifecycle profile, they’ll find it is superb. It’s also a great fuel from a technical perspective, resulting in cleaner more efficient engine operation and cleaner tailpipe emissions. It’s not a competitor to e-fuels, or to EVs [electric vehicles] or public transport, or changes to urban living patterns, [but] the vast majority of all biofuels in the world do not impinge on food supplies.”

T&E is also also not keen on such biofuels, though, citing issues with such products as used cooking oil (UCO) fuel, which it says triggers higher demand in some markets for environmentally damaging products such as palm oil and the think tank claims that biofuels can and do displace food crops from existing arable land.

If – and it’s a big if – e-fuel production can be ramped up, using only renewable energy, and brought to a level where the fuels it makes are cheap, accessible, and good for the environment, then maybe there’s something in this. Unless all of those criteria can be met, though, it feels very much like trying to wean oneself off a harmful addiction, while someone tries to tell you there’s a better, safer drug just around the corner.

Neil Briscoe

Neil Briscoe

Neil Briscoe, a contributor to The Irish Times, specialises in motoring