The European Commission’s target of making Europe climate-neutral by 2050 will require the transport sector to make major changes. The targets can be achieved in large part by reducing greenhouse gas emissions from cars. But which drive systems and fuels are best suited to making this happen? How do electric cars compare to other alternatives? Are the emissions generated in their production offset by their use on the road? Researchers at the Universität der Bundeswehr in Munich have looked into these and other issues – and arrived at an unequivocal conclusion.
In the course of their comparative analysis, the researchers put almost 800 different models of car – from models with conventional ICEs to electric cars, fuel cell cars and gas-powered cars – under the microscope and considered their entire life cycle, including manufacturing, service life and recycling/scrapping. In terms of its scope, the Munich researchers’ study is unique, while its comprehensive approach makes the cars throughly comparable.
This integrated approach is vital in order to make meaningful statements about the climate compatibility of different cars. Fully electric cars rank relatively poorly in a comparison of the first phase of the life cycle. The emissions generated in the production of batteries, such as those for a fully electric Tesla Model 3, are comparable to the emissions generated by driving a diesel Volkswagen Passat 2.0 TSI for 18,000 kilometres.
However, EVs make up for their front-loaded greenhouse gas emissions by their duration of use, and certainly by the time it comes to recycling. In both phases, electric-powered cars with batteries perform significantly better than petrol or diesel cars with ICEs. Battery-electric vehicles and fuel cell cars do not generate any hazardous emissions while on the road. As a result, their climate footprint compared to other fuel and drive types improves with every kilometre driven.
Batteries play a prominent role in the recycling phase. Even today, companies including Umicore, Northvolt, Li-Cycle and Redwood Materials are already capable of recovering well over 80% of the key materials in batteries (cobalt, lithium, nickel, manganese, etc.) for future reuse.
When charged with green electricity, plug-in hybrids and pure-electric cars can reduce total emissions by 73% to 89% compared to cars with a combustion engine. Alternatively, when fuelled with commercial grey hydrogen, fuel cell cars also achieve a similar reduction in greenhouse gas emissions (60%) to electric cars charged with conventional electricity.
In general, renewable fuels and energy sources lead to the lowest emissions over the life cycle of a car.
Overview: Emissions by drive type
- Petrol-driven cars generate the most emissions
- Diesel cars: 20% less
- Hybrid cars with an electric/diesel motor (and conventional electricity): 33% less
- Hybrid cars with an electric/petrol motor (and conventional electricity): 50% less
- Natural gas cars: 50% less
- Fuel cell cars (with hydrogen derived from fossil fuels): 60% less
- Electric cars (with conventional electricity): 66% less
- Hybrid cars with an electric/diesel motor (and green electricity): 70% less
- Hybrid cars with an electric/petrol motor (and green electricity): 75% less
- Biogas cars: 80% less
- Electric cars (with green electricity): 89% less
Results: Pure-electric cars are particularly clean
The results are clear: Even when powered by the current German electricity mix, pure-electric cars produce the lowest levels of greenhouse gas emissions. In fact, they only generate one-third of the pollution produced by a petrol-driven car over the course of their life cycle. If an electric car is powered using exclusively green electricity – such as with a PV system on your own roof or a company car port – they only generate one-tenth of the emissions.
Finally, as the authors note in the conclusion of their study, electric vehicles like battery-powered EVs and fuel cell vehicles on the one hand, and biogas-powered vehicles on the other, should become the preferred choice for drivers. This is because these vehicles rely on at least partially renewable energies to power them – and this is better for the climate.
However, it is important that the electricity, hydrogen or biogas used to power the car is actually produced in an environmentally friendly manner. Achieving this at scale currently seems unlikely for biogas and hydrogen, so it is quite possible that fuel cell cars will prove their worth as part of the vehicle fleet of companies or taxi firms if producing green hydrogen is already part of their daily operations.
The study also highlights another aspect of particular interest to SENEC: Electric cars should be charged with electricity produced as close as possible to the charging point. This means, ideally, that the electricity should not be generated in a sprawling wind farm hundreds of kilometres away but rather on the roof of the house, company or solar car port itself – and EVs should be charged using EV chargers or charging points that facilitate solar-optimised charging.
In the future, electric cars will ultimately also serve as mobile, virtual energy storage systems, especially for midday peaks in the summer months. By focusing on the winter months when calculating energy demand, solar systems will often produce surplus energy in summer, at least around noon. The more comprehensively electric cars are integrated into this process by fleet operators, the more secure and efficient the future energy system will be – with EVs and domestic storage systems serving as a decisive stability factor.
Background to the study: The paper is called “Total CO2-equivalent life-cycle emissions from commercially available passenger cars” and was published in Renewable and Sustainable Energy Reviews (Volume 159, 2022) – one of the most internationally renowned journals for sustainable energy supplies and renewable energy. The authors are: Johannes Buberger, Anton Kersten, Manuel Kuder, Richard Eckerle, Thomas Weyh and Torbjörn Thiringer. Read the study online here.