It would be desirable for synthetic fuels to come to used only to decarbonise so-called "hard" sectors to abate", such as air and sea transport, and not were instead used for the road transport sector for the Which vehicle electrification remains the best solution for the reduction of emissions. This is highlighted by Transport & Environment (T&E) presenting an analysis that highlights the limits biological and synthetic fuels in terms of emissions, efficiency, volumes and impact on air quality and considers that they are not useful for the decarbonisation of road transport. The study of the environmental organization compares biofuels, e-fuels and electric cars, analyzing emission factors of greenhouse gases, efficiency, production volumes (capacity of satisfaction of demand) and emission of local pollutants.

Biofuels and e-fuels, according to T&E, show obvious limits from different points of view. Throughout its life cycle, For example - explains the analysis - vehicles powered with these Fuels generate more emissions than electric vehicles. In addition to creating tension in the market, entering into competition with crops for food use, traditional biofuels, in addition, can release up to three times of greenhouse gases superior in comparison with fossil diesel. On the other hand, the advanced biofuels or produced from waste and residues are able, in theory, to reduce emissions by up to 88% compared to a fossil fuel. These vectors, therefore, do not achieve a zero-emission target and, notes T&E, discount the limited availability of sustainable quantities of raw materials on which they depend. Their use, therefore, should be limited to compartments which cannot be easily electrified, such as those of air transport and of maritime transport.

On the emissions front, the rejection is no less clear of e-fuels, which still do not exist on the market. The analysis notes that during the life cycle synthetic fuels will generate 53% more emissions than vehicles electricity to 2030, the year in which, according to data from the refining, e-fuels will be available from distributors, However, it represents just 0.4% of the offer. Electric cars, on the other hand, already today and with the current mix energy, allow to reduce by 69% on average at EU level (and of 62% in Italy) CO2 emissions over the life cycle in the comparison with gasoline cars.

Biofuels and synthetic fuels also highlight significant efficiency issues, revealing returns very low overall from the production process to combustion in an endothermic engine. With the same mileage, in particular, powering a biofuel car, or A e-fuels can involve an amount of energy up to five times more than a vehicle requires electric.

Another critical aspect - underlines the T&E study - is the scarce availability of these fuels, a characteristic affecting its significant use in decarbonisation of the automotive sector. Today the use in purity of advanced biofuels or biofuels from waste and residues would allow feed just 5% of the Italian circulating fleet (1.9 million of cars), a share that could rise to a maximum of 20% (6.9 million) in 2030 if ENI's estimates were confirmed, which counts on achieve an annual biorefining capacity of five million tons of HVO (Hydrotreated Vegetable Oil) at the end of the decade. With the same energy and with the same Mileage, the study notes, could already be powered today - compared to current production volumes - 6.9 million electric cars, to then reach 24 million, or 70% of working capital, in 2030. E-fuels, according to data released by themselves producers, as mentioned, will constitute, just 0.4% of fuels available to the distributor in 2030. Their incidence is expected to rise to 3% in 2035 and 16% in 2040. Own in the face of the limited volumes available, concludes T&E, the synthetic fuels could only be used for decarbonising sectors such as aviation and shipping and would therefore be wasted if used in cars.