Why Synthetic Fuels Still Won’t Save Internal Combustion In Cars

With more work being poured into making synthetic, low-emission ‘eFuel’ viable, it seems like there might be a long-term future for ICE in cars… but it’s unlikely
Why Synthetic Fuels Still Won’t Save Internal Combustion In Cars

Breakthroughs in synthetic fuel technology should have raised eyebrows among any self-respecting petrolhead. The idea, evidenced this week by Porsche’s eFuel activities in Chile, is that we can generate the same lovely power figures and greater thermal efficiency while producing much less carbon dioxide and almost none of the harmful particulates emitted by exploding fossil fuels. Brilliant! But wait.

While Porsche plans to introduce them into its motorsport programmes and experience centres, with a view to potential road-going applications, a new report from engineering expert Ricardo (builders of McLaren’s V8s, among many other things) says a large-scale adoption of the technology in road cars is best avoided in favour of “more efficient” solutions.

Such reports are usually snappily-named, and this gem is no exception. ‘Renewable electricity requirements to decarbonise transport in Europe with electric vehicles, hydrogen and electrofuels’ was produced on behalf of Transport & Environment, a European campaign group focused on cleaner transport. Ricardo’s conclusions make dismal reading for anyone hoping for a lengthy stay of execution for new combustion engines.

Why Synthetic Fuels Still Won’t Save Internal Combustion In Cars

Top of the list of its findings is that direct electrification is the best way to reduce carbon emissions from cars between now and 2030. The report doesn’t look much beyond how effective the various technological paths are in terms of reducing emissions, so the usual caveats still apply to mass adoption of BEVs, but Ricardo essentially says the faster we all convert to battery-powered cars, the better, at least in terms of street level emissions.

Interestingly, the study also looks at how much renewable electricity is needed for all this, the assumption being that we aim to move towards 100 per cent renewable power for everything in order to factor-out the extremely high carbon emissions involving in manufacturing BEVs. As such, a lot of the numbers are based on forecasts and best-case guesstimation. Ricardo believes there’s enough potential renewable energy capacity in Europe to effectively decarbonise road, air and shipping transport by 2050, but only if someone comes up with effective zero-carbon solutions for how to power the big stuff like aircraft and ships. Don’t want to hit an unexpectedly strong headwind and run out of battery charge somewhere over the Pacific, do we?

By 2050, Europe will need about 2800 Terawatt-hours (TW/h) of renewable juice to supply the transport industry, says Ricardo. The pan-continental potential for generation across solar, wind and geothermal is up to 28,000TW/h. In theory, then, it’s possible to target a fully renewable energy supply within decades and Ricardo says the most efficient way to power cars is via batteries that can directly accept the generated power rather than wasting that same energy cracking usable hydrogen or manufacturing synthetic fuel.

Large vehicles, for which long recharge times are impractical, may still use hydrogen - or eFuel
Large vehicles, for which long recharge times are impractical, may still…

As obviously biased as Transport & Environment is, as an entity, the logic is solid. Efficiency everywhere will hopefully help humans achieve some sort of balance with the natural world, unless nothing is done about global population growth, in which case this is all futile and we may as well all get ourselves some rollin’ coal.

It’s not that there’s no future for synthetic fuels; it’s just not likely to be a future that sparks a new era of investment in ICE. The fuels will eventually need to be targeted at existing combustion-driven cars, fully compatible with their technology and cheap enough not to penalise those people who can’t afford the (currently) off-putting expense of buying or financing a family-sized electric car. It’s a realistic and effective way of lowering the emissions of fossil fuel-powered vehicles, but it’s really only a twilight-hours mitigation. The revolution will still be measured in volts.


V-Tech and EcoBoost kicked in yo

Synthetic fuels will really only be used in edge cases like racing or some shipping fleets. They are carbon neutral on paper, but when you consider the amount of energy being put in vs fuel produced, its not that great. Same goes for hydrogen. Suppose you have 100KWh of electricity. If you put all that in a battery, the round trip efficiency will be around 90+%. For hydrogen, this is around 30%. Hydrolysis, pressurization, and fuel cells themselves all have significant efficiency losses.

It’s not that synthetic fuels or hydrogen are bad solutions. On paper, they look great. The problem is that battery technology has advanced so much that the former two can only maintain relevance in sectors like shipping and heavy vehicles, where refuel time and energy density is more important than energy efficiency. However, all its going to take is a breakthrough like mass produced metal-air batteries or reasonably good liquid flow batteries to kill hydrogen and synth fuels in these cases too.

12/12/2020 - 09:40 |
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Yusuf Ashari

I knew this one coming….. at the first second when I was relieved that there’s a solution for combustion engine in the future in form of synth fuel/gasoline, I suddenly thought, “now that we found the sustainable way to keep ICE engine running in the midst of EV revolution, there’s another problem somewhere…..”. At first I thought the problem was “is there a motor oil from sustainable resources to lubricate these ICE cars in the future?”. As it turns out , it’s efficiency related. Doesn’t look too good , but that’s real world. Someone needs to find the way to balance this thing out, otherwise the petrolheads are going to run amok.

12/14/2020 - 02:00 |
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This is a great article that gives a better perspective into what efuels can and cannot do.
It’s a shame that other magazines and large websites just run with the original story without taking a critical look at it.
Kudos to carthrottle and Matt for doing a great job.

12/14/2020 - 10:25 |
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The comment about slowing the increase in population of the world is so true. Humans as a race have over populated the world there are many documentaries on this, they estimate the world can roughly sustain about 4.5 billion people and we are already at 7 and a bit billion.
If that issue doesn’t get solved then sadly all this stuff will be in vain.

12/14/2020 - 15:33 |
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