The use of renewable electricity introduced directly into battery electric vehicles is a more efficient and ecological option in road transport than synthetic hydrocarbons derived from hydrogen (electrofuels, e-fuels, e-fuels or synthetic fuels).
The data shows that if renewable electricity (such as wind or solar) is used and inserted directly into a car battery, a total energy efficiency of 77% is obtained, that is, 77% of the initial energy is what spins the wheels. In the case of e-fuels, it is only 20% for electro-diesel and 16% for electro-gasoline.
The use of e-fuels in road transport “would be an aberration from the point of view of energy efficiency”.
This is indicated by a study by the organizations Climate Strategy, Ecodes, Ecologistas en Acción, Fundación Renovables, SEO/BirdLife and Transport
The document thus seeks to respond to the uncertainty generated by the promoters of e-fuels among citizens regarding their supposed advantages in dealing with the decarbonization of road transport
The study indicates that moving a road vehicle (car, van, bus, truck) using green hydrogen in a fuel cell or through electrofuels is, respectively, about 2.5 times, in the first case, and between 3.5 times to 5 times, in the second, more energetically expensive than the direct use of renewable electricity in battery vehicles.
For these organizations, the decarbonization of transport through renewable electricity is a major challenge.
Therefore, “there is no margin to use renewable electricity in an inefficient way.” Allowing the use of e-fuels in road transport, when there are much more efficient technical alternatives such as the direct use of electricity (battery electric vehicles), entails a huge energy penalty and risks derailing the entire effort to decarbonizationâ€.
If the use of green hydrogen or e-fuels for road transport were promoted, a large amount of additional renewable electricity would have to be generated to produce them, “which would require the installation of a significant number of extra renewable energy plants.” , with the consequent impact on the territory and potentially on biodiversityâ€.
Renewable electrofuels (also called e-fuels, e-fuels, synthetic fuels or synthetic hydrocarbons) and hydrogen itself make up the RFNBO (acronym for “Renewable Fuels of Non-Biological Originâ€) are renewable liquid and gaseous fuels whose energy content does not comes from biological sources.
These organizations consider it “false†that the use of e-gasoline or e-diesel in vehicles is climate neutral. “Its use in a combustion engine produces two of the most powerful greenhouse gases: methane (CH4) and nitrous oxide (N2O)†they indicate.
If all new petrol and diesel cars sold in 2020 were to run on e-petrol or e-diesel, the additional CO2-eq emissions (from methane and nitrous oxides) would be equivalent to about 50,000 more fossil cars on the road of the EU in just one year, they add.
They also conclude that cars powered by e-fuels emit as much nitrogen oxides (NOx) as engines that burn fossil fuels. NOx is a toxic substance responsible for poor air quality in our cities. In addition, “the use of e-fuels increases toxic carbon monoxide emissions, which is also harmful to our health.”
His third argument is that “e-fuel production is expensive†and that “therefore, they will be sold at a high priceâ€. In fact, they say, even with an optimistic approach, a driver with a synthetic gasoline car in 2030 would spend 10,000 euros more than one with a battery-electric car over 5 years. “An unapproachable price difference for the majority of Europeans.”
E-fuels could not power even the 2% of the cars in circulation forecast for 2035. Indeed, the industry’s own analysis shows that the volume of electric fuels that is expected to be available in 2035 would only serve to power five million cars from the estimated 287 million park in the EU. Not even the industry trusts e-fuels as a viable alternative to fossil fuels.
On the other hand, the availability of e-fuels is practically non-existent. “They are not a market-ready solution, no. There are no cars running on e-fuels on our streets beyond testing, so they don’t exist as an alternative todayâ€, he concludes.
Transport in Spain is the sector with the greatest weight in gas emissions (29.6% of the total) and, within this, road transport accounts for 27.8% of total emissions, according to the ” National inventory of greenhouse gas emissions: series 1990-2021â€, of March 2023, from the Ministry for the Ecological Transition.
