Prioritising energy efficiency in the European transport ecosystem of tomorrow

Energy efficiency refers to the amount of energy, measured in kilowatt-hours (kWh), required to travel a certain distance (kilometers) per passenger. The more energy-efficient a mode of transport is, the less primary energy is needed to be produced for the vehicle to travel the same distance, regardless of the energy’s source—whether it comes from fossil fuels, nuclear energy, or renewable sources.

Among all transport modes, trains are by far the most energy-efficient for long distances[1]. Europe is already a global leader in rail transport, and a concerted push to increase modal shift from road to rail could unlock substantial efficiency gains. We thus support the call to further roll-out of TEN-T as well as plans for an ambitious European high-speed rail network, night train and rail freight. The ecological advantage is especially there for freight transport. On the local level, public passenger transport by metro, tram, bus and urban rail collectively moves large numbers of people, using less energy and emitting less CO2 per passenger-kilometre than private vehicles.[2]

However, passenger cars remain at the center of current political debate. They represent the most widespread form of personal transport and are undergoing major changes amid political debates and upcoming review of the CO2 Standards for cars and vans. When it comes to energy efficiency, not all cars are equal. Energy efficiency among cars varies dramatically, depending on the type of propulsion used. For example, as illustrated by graph 1 above, on the same amount of energy of 15 kWh, similar passenger cars travel very different distances[3]:

• An internal combustion engine vehicle running on synthetic fuels created from renewable energy and climate neutral can travel 20km;
• a hydrogen fuel cell vehicle, running on synthetic fuels created from renewable energy and climate neutral can travel 35km, using the same amount of energy.
• a battery electric vehicle (BEV) can travel 100 km on the same amount of energy, five times more the range of the ICE car.

It is clear that BEVs significantly outperform vehicles powered by e-fuels in terms of energy efficiency.

[1] https://www.iea.org/energy-system/transport/rail

[2] In its Urban Mobility Framework (point 2.4), the Commission writes "Public transport such as urban rail, metros, trams, buses, water buses, ferries or cable cars represent the safest, most efficient and sustainable ways for large numbers of people to travel.". There is also a comparison of emissions per mode that includes buses (and coaches)  in the EEA Transport and Environment Report 2021 (figure 4.3)

[3] Research Center for Energy Networks and Energy Storage

Producing e-fuels requires much more energy than producing fossil fuels or using direct electrification when looking at energy use from production to tank. The main issue with e-fuels is their low efficiency throughout the production process. In order for an e-fuel to truly be carbon-neutral, each step—making hydrogen, capturing carbon, and then synthesizing the fuel— needs to be renewable. However, each of these steps require energy and result in large energy losses. This makes e-fuels less efficient in areas where electrification use is possible, especially since electric motors are far more efficient than combustion engines[1].

While a BEV uses 77% of the primary energy to move its wheels, a vehicle powered by e-fuels converts only 20% of the original energy input into motion[2]. The later would thus need about four times more primary energy than the former to travel same amount of kilometres. This large difference underscores the need to prioritise more efficient technologies. Energy efficiency is not a marginal criteria.

Additionally, such an efficiency gain is without counting on the benefits BEVs can have for the energy system if grid-integrated thanks to smart and bidirectional charging, where their batteries can improve the efficiency of the entire energy system. As the making synthetic fuels in itself is already very energy intensive. Each Kwh used for the production of synthetic fuels is one that cannot serve other, more efficient means.

[1] https://www.spglobal.com/_assets/documents/ratings/research/101595057.pdf

[2] https://www.transportenvironment.org/articles/e-fuels-too-inefficient-and-expensive-cars-and-trucks-may-be-part-aviations-climate-solution

To ensure that Europe’s future vehicle fleet is as energy efficient as possible, we recommend the following policy actions:

• No U-turn: Any early review or any U-turn in already agreed policy is detrimental for investment confidence in the energy transition.
• Limit the role of e-fuels in CO2 standards: In the upcoming review of the CO2 standards for cars and vans, we urge policymakers to restrict the use of e-fuels to niche markets that cannot be directly electrified, for emergency services, or vehicles of specific usages such as forestry.
• Focus e-fuels on hard-to-abate sectors: Divert the use of limited e-fuels to other sectors where electrification is still not an option and where so much is needed: aviation, long-haul maritime.
• Introduce differentiated taxation: Vehicle taxation should be tied to energy efficiency. Registration taxes, road taxes, and fuel duties should favour energy-efficient vehicles. For instance, a bonus-malus system could be introduced, where less efficient vehicles face higher taxes, and more efficient options benefit from tax breaks. The revision of the Energy Taxation Directive could be instrumental in this perspective.
• Prioritise energy efficiency in public procurement: Public procurement can be a powerful tool to set an example. Green public procurement criteria should prioritize the energy efficiency of vehicles used in the public sector. By including energy efficiency requirements in public tenders, governments can drive demand for the most efficient technologies. The Net Zero Industrial Act already paves the way in this direction.

Energy efficiency is not just a technical consideration, it is a strategic imperative for Europe’s energy security, economic competitiveness, Europeans’ cost of living, and environmental sustainability. By prioritising the development and use of the most energy-efficient transport modes, the EU can reduce its dependence on imported fossil fuels, lower costs for consumers, and ensure that the shift to renewable energy is as efficient as possible.
We strongly urge you to take decisive action in the upcoming CO2 standards review and to adopt policies that will promote the most energy-efficient transport solutions. This is essential to meeting the EU’s decarbonisation objectives and securing a sustainable future for all Europeans.