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Not all of us are onboard with the transition to electric vehicles. Renewable energy options promise to help with the pressure at the pump and climate change, but so far, no one method–solar, hydro, wind, or alternative fuel–have managed to knock oil from its pedestal … yet.

Electric cars are off to a strong start when it comes to getting renewable energy out on the road.

Still, not everyone is sold yet, which is why electric cars are facing a familiar-looking contender: synthetic fuel. Companies like Porsche and BMW are investing a lot of money into it. With synthetic fuels, it might be possible to make your existing gasoline car carbon neutral… but will it actually work? And for the Undecided community out there, stay until the end for a little announcement.

Synthetic fuels, in summary

The battle for the future of our roads isn’t over, which is why there’s still a lot of interest in synthetic fuels. These are also known as synfuel, or in some circles, “e-fuels,” and are a carbon-neutral fuel alternative engineered for combustion engines.

You may be asking yourself, ”Isn’t burning stuff bad for the environment?” Well, not completely. Fossil fuels take sequestered carbon from the earth (in the form of hydrocarbons via crude oil), combust it, and then release that CO2 into the atmosphere, ultimately increasing the amount of CO2 aboveground. Synthetic fuels, on the other hand, take a different approach: they take the CO2 already in the atmosphere and combine that with hydrogen to make a usable fuel. This fuel is combusted like fossil fuels, but unlike fossil fuels, synthetic fuels simply return that CO2 back into the atmosphere for a net-zero carbon footprint.

How do these synthetic fuels “borrow” atmospheric carbon? As it turns out, we’re still discovering the best way to do this.

Biofuels use the time-tested fruits of photosynthesis to access that sweet, sweet carbon. These fuels are produced from crops like soybeans, sugar cane, algae, corn, and even some forms of grass! The appeal behind this synthetic fuel isn’t hard to see: there’s (literally) tons of biomass on the Earth, and not all of it is food-grade material. This “natural” fuel is already partially in circulation, and you can find diesel blends (B20) already in circulation.

E-fuels, on the other hand, are more what people think of when you say “synthetic” fuels. (These fuels are the epitome of “if you don’t have any carbon laying around, store-bought is fine.) These fuels bypass photosynthesis altogether, instead opting for “lab-made” fuels made via electrolysis, methanol, the Fischer-Tropsh process, or even the excretions of certain microorganisms. The fundamentals stay the same: you take CO2 out of the atmosphere, combine it with hydrogen, zap with your favorite chemical magic, and ta-da! That carbon and hydrogen turns to synthetic ethanol and water (otherwise known as synthetic diesel.)

Both of these types of synthetic fuels offer the same outcome: a carbon-neutral energy source that doesn’t demand the same industry overhaul that electric cars require. If this tech is so great and still lets us keep the status quo, minus the environment-killing emissions, then why haven’t synthetic fuels taken over yet? Are synthetic fuels really a threat to the electric car industry which is off to a really strong lead?

To answer that, we have to see how synthetic fuels and EVs stack up in real life. Let’s take a look at how these two technologies compare on the three biggest fronts: efficiency, costs, and environmental impact.

How They Compare: Efficiency

All renewable energy sources come with a limiting factor, like the impact of season changes and mass storage for solar power. Synthetic fuels are no different, but for them, their Achilles heel tends to be their efficiency.

When it comes to energy, we’re mainly worried about three things: 1) energy density (i.e. how much energy is available, 2) energy transfer (i.e. how quickly energy can get from A to B, and 3) energy efficiency (i.e. how much of that initial energy remains from the source to the endpoint).

If we translate that, we’re essentially asking three questions in regards to using synthetic fuel or EVs:

  1. How much energy can we pack into our passenger vehicle (to avoid unnecessary and inconvenient pit stops to recharge or refuel)?
  2. How many steps does that energy have to go through to get from our engine to the wheels?
  3. How much of that energy remains when it gets to the wheels? In other words, how much is lost during the conversion process.

In terms of energy density, synthetic fuels have shown some awesome potential! (Figuratively AND literally!) On the biofuel side, ethanol and biodiesel average 26-38 MJ/kg1, which isn’t too far off from current fossil fuels (44-55 MJ/kg). Electrofuels seem to hold their own as well at around 32MJ2. Lithium-ion batteries, on the other hand, fall a little short in this area at around 2.5 MJ; ouch! Keep in mind that this is only one consideration of energy efficiency.

So what does that mean for us when we get behind the wheel? In short, synthetic fuel is actually pretty great for energy storage. If you have larger vehicles that need to store a lot of energy at once in a relatively condensed space —like planes and shipping freighters, for example—then synthetic fuels are a good match. We’ve already seen the maritime industry take on synthetic fuels, as companies like the shipping giant Maersk begin to incorporate methanol-fuelled vessels3. I actually touched on this in a recent video. This is why biofuel is mainly geared towards biodiesel, not biogasoline.

The next consideration is to remember that we eventually want that energy to get out of storage and into action. This is unfortunately where we start to see synthetic fuels fall behind. Battery-powered electric vehicles have an advantage here when it comes to energy transfer, because at the end of the day, that energy process is simpler. (Well, relatively, at least!)

The EV energy transfer process has three main steps. The energy is generated at the source, transmitted to the battery, and then transmitted to the motor—done! Synthetic fuels, on the other hand, have a few more processing steps along the way. That energy has to go through electrolysis and carbon capture, undergo the power-to-lipid process (essentially stabilizing the product for transport), and then must travel from the fuel tank to the engine. Synthetic fuel has to navigate more moving parts in the engine for the energy to be useful.

The result? Transferring energy via synthetic fuel takes more steps. With each step, the efficiency drops.

In particular, biofuel has an energy efficiency problem. You need just over 7,000 kCal worth of biomass to create one liter of ethanol, but that end product only contains 5,130 kCal; the process itself is energy-negative4! Unfortunately, photosynthesis is a generally inefficient way to turn sunlight into energy, at least for our uses.

On the other hand, battery-powered vehicles boast an energy efficiency rate of around 69% (meaning 69% of that energy survives the process from storage to wheels). Synthetic fuels? You’re looking at an energy efficiency rate of just 13%5.

That means the BEST synthetic fuel still takes two times the energy to move a combustion vehicle the same distance as the WORST EV. EVs simply travel further on the same amount of energy.

How They Compare: Cost

So let’s talk about one of the biggest hurdles when it comes to synthetic fuels: the cost.

Biofuel in particular has a turbulent economic landscape. Oil prices (as we’ve all seen lately) can be a little, well, unstable. When oil prices drop, they drag the profit margin of biofuels down with it. Combine that with the rising cost of corn, and you’re looking at a measly $1 profit per ton produced6.

The corn and soybean industries are heavily subsidized by the government., Some cynics even see the ethanol-based fuel industry as a way to provide jobs that otherwise may not exist.

Synthetic fuels are in a similarly tight spot today. It’s hard to find a supplier who can produce large enough quantities to make a difference in the market. At $94 to $232 per ton of CO2, synthetic fuels are just plain expensive to produce7. In terms of upfront costs, it can take **millions **of dollars to start up a synthetic fuel plant, and production itself offers razor-thin profit margins that make restaurants look like a lucrative business venture.

With the low profit and high upfront costs, synthetic fuel producers can find it hard to entice wary private investors, which makes it hard to raise the capital they need to get going. Because of this, synthetic fuels work best economically in areas with tighter emission regulations and government subsidies.

So far, we’ve only discussed the production costs. What about the actual cost to the consumer? Unfortunately, synthetic fuels don’t do much better. You may shudder at the thought of the current prices at the pump, but in comparison, synthetic fuels can cost an equivalent of $10 to $38/gallon8! (That’s $2.64 to $10.04 per L!) **Ouch! **

At those crazy prices, who in the WORLD would still be gunning for synthetic fuels? Well, it’s generally more popular in social circles where those costs are a drop in the bucket. Performance and premium car companies like Porsche, BMW, and Formula One are on the front lines, incorporating carbon-neutral sources like synthetic fuels. For those buyers, the price tag of synthetic fuel may not be a dealbreaker. For the everyday driver, however, that’s quite the sting in the wallet.

How They Compare: Infrastructure

Switching away from fossil fuels will inevitably require a change in our infrastructure, so how would things look different in a world based on synthetic fuels versus a world running on electric cars?

Surprisingly, a world running on synthetic fuels may not look that much different than the one we have now! That’s because e-fuels can be distributed with our existing infrastructure, like the 115,000 gas stations in use today in the US. On a more personal level, we could potentially use our old car models as well; no need to go out and buy a brand new electric car! This is a huge advantage for those who drive classic and vintage cars.

Making the switch to synthetic fuels could be relatively easy logistically and culturally. Even climate change nay-sayers may be less resistant to switch to synthetic fuels if they can keep their old car and the semblance of their old lifestyle. Unlike electric cars, vehicles that run on synthetic fuel can still be noisy, which … depending on who you are … could be a plus. Some performance car makers (like Porsche) have already adopted some synthetic fuel models to highlight the tech.

But of course, nostalgia doesn’t make up for some of synthetic fuel’s blatant downsides. (Remember that $38/gallon price tag?) Synthetic fuels are still expensive, inefficient, and to some, just a last gasp effort for oil companies to stay relevant. They also still face distribution limits, including the recent Supreme Court decision to retain limits on the sale of biofuels like E159.

On the other hand, electric cars (and by extension, their charging stations) are already being integrated into our infrastructure, and they show no signs of stopping. Just the opposite … it’s accelerating.

Environmental Impact/Emissions

Last (but certainly not least), we need to see how synthetic fuels live up to their carbon-negative promise. Are synthetic fuels a formidable alternative to fossil fuels?

Well … maybe.

Both synthetic fuels and EVs should (in theory) have zero lifetime CO2 emissions, or at least, near zero. In reality, though, this depends on the manufacturer. Right now electric vehicles require those pesky lithium ion batteries, which require the painstaking excavation of precious minerals AND a whole lot of electricity, neither or which are always obtained from clean sources. The result? Those lithium batteries can contribute around 25% of the electric car’s lifetime CO2 emissions10.

You also need to consider where the electricity itself comes from. Electricity from coal still results in emissions, even if the vehicle itself is emission-free. It’s still cleaner than running a car on gasoline though. The source of that electricity is what ultimately matters in whether the production is green or not, which is why producing an EV car can produce around 20 tons of CO2 before it’s ever driven off the lot. However, for EVs, that is slowly changing as our electricity production gets cleaner.

Synthetic fuel production runs into similar predicaments. For example, Porsche’s new synthetic fuel plant still requires concrete, which is one of the biggest sources of CO2 emissions in construction. That’s not even considering the emissions that come from shipping the fuel in tankers OR the refineries required to make the fuel usable!

Biofuels have their own environmental impacts to consider. Over 90 million acres of farmland in the US is used for corn, and around 40% of that is used for the ethanol that supplements about 10% of the gas used by US consumers today11. In the last decade, those croplands expanded by 1 million acres per year for corn primarily, edging out natural habitats in the process. Corn is also hard on the soil, pulling many nutrients from it. This means farmland must have nutrients supplemented or crops rotated to keep the land productive.

Using biomass for fuel also comes with other environmental concerns, including insecticides, loss of biodiversity, potential food insecurity, and excessive water usage. To produce one gallon of ethanol from corn grain can take about 2-9 gallons of water, depending on the method used to convert the grain. Keep in mind that the average biofuel plant is looking to produce millions of gallons of fuel each year12! Biofuels are ultimately a zero-sum game; the land, crops, and water used for biofuels can’t also be used for food.

Some producers have tried to mitigate this by switching the biomass source. For example, sugarcane biofuel is actually an energy-positive process, but it can also lead to deforestation in the Amazon, as it is still cheaper to import it from there than to grow it domestically. Other sources, like algae offer promising results, but they’re still energy-intensive and expensive, negating their current environmental benefits.

Could synthetic fuels be produced in an environmentally-safe way? Certainly. Would this be the cheapest option? At this time, it doesn’t seem so. This is why I spend so much time in a lot of my videos discussing costs … manufacturers (and all of us) are more likely to flock to low-cost options, especially in an economically-strained industry.

Ultimately, if there is a higher cost, the manufacturer will pass it on to us, the consumers. If you can get one fuel cheaper than another, which would you choose?

Conclusion

Synthetic fuels are a promising front in many ways, but they’re not going to dethrone electric vehicles anytime soon … if ever. Synthetic fuels will not be the magic bullet that some environmentalists wanted or what the industry craves. Synthetic fuels could be helpful to transition any naysayers who are still attached to combustion engines including oil companies, and they may even ease the transition away from fossil fuels for large form transportation like ships and planes … where batteries aren’t an option yet.

For now, and the foreseeable future, EVs are still the strongest contenders for everyday passenger vehicles. Still, we all need to be aware of the “behind-the-scenes” emissions and environmental impact that these technologies pose, including the high potential for greenwashing in the wrong hands.


  1. “Energy density.” Energy Education
  2. Engineering Explained. No, Synthetic fuels Won’t Replace Electric Cars..
  3. Collins, Leigh. “Shipping giant Maersk to become major green hydrogen consumer as it embraces methanol fuel | Recharge.” Recharge News
  4. Biofuel Impacts on World Food Supply: Use of Fossil Fuel, Land and Water Resources. Energies 2008, 1, 41-78
  5. The Royal Society. Sustainable synthetic carbon based fuels for transport. 2019. Sustainable synthetic carbon based fuels for transport
  6. Everything Science. “What are Biofuels and Where are They Going?”
  7. Bandit, Lana. 2018. “We may soon be able to make gasoline from thin air.” The Week
  8. Edelstein, Stephen. 2020. “Synthetic fuel is how Porsche intends to keep its classics on the road.” Motor Authority
  9. Kelly, Stephanie. “U.S. Supreme Court leaves in place limits on higher-ethanol fuel blend.” Reuters, 10 January 2022
  10. Hall, Dale; Nic Lutsey. 2018. “Effects of battery manufacturing on electric vehicle life-cycle greenhouse gas emissions.” The International Council on Clean Transportation
  11. Real Engineering. “The Problem With Biofuels.”
  12. Farm Energy, 2019. “Water Use and Sustainable Biofuel Production”. Farm Energy
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Matt Ferrell
Matt Ferrell lives in the Boston area and is a UI/UX designer by trade, but has always been obsessed by technology and how it works. In 2018 he started his YouTube channel, Undecided with Matt Ferrell, where he explores sustainable and smart technologies like EVs, solar panels, and smart homes.

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