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Doubts over EV carbon credentials

Uwe Hessler
April 25, 2019

A Tesla Model 3 has a worse life-cycle carbon footprint than a similar-sized Mercedes diesel car, the renowned German think tank has found. It warns that electric vehicles are "no panacea" against climate change.

E-Auto | VW Golf
Image: picture-alliance/dpa/J. Woitas

When the ifo institute released its findings shortly before Easter, its verdict amounted to no less than the slaughtering of a sacred cow of German climate policy: electromobility.

The claims made by former ifo president Hans-Werner Sinn, physics professor Christoph Buchal and ifo energy expert Hans-Dieter Long could deal a big blow to this country's efforts to reduce traffic-related CO2 by 40% over the next decade.

Germany is heading down a blind alley, the authors boldly state, because electric vehicles will "barely help to cut emissions" as battery-powered cars emit between 10% and "up to a quarter" more CO2 than a conventional diesel car.

The research trio compared the CO2 footprint of a Tesla Model 3 with those of a Mercedes 220d diesel car and a Mercedes C Class model converted from petrol to liquefied natural gas (LNG).

Their focus was on the cars' whole life cycle emissions — from the first nut welded right down to the cars' final kilometer. The life cycle in terms of distance driven was arbitrarily set at 150,000 kilometers (93,205 miles) for better judgement.

EU greenwashing?

The European Commission currently counts electric cars as "zero-emission vehicles" as it seeks to push car fleet emissions in Europe below 95 grams of CO2 per kilometer (152.8 grams/mile) by 2021. In the decade to follow, a cut of another 35% is decreed, down to 59 g/km (94.9 grams/mile).

The ifo study calls this into question, saying that EVs are neither emissions-free nor are these targets achievable without cooking the data.

The authors admit that carbon data especially on the upstream parts of the manufacturing process is still weak. But all available information on CO2 emitted during manufacturing, battery and fuel production, as well as electricity generation, already suggests the Tesla 3 electric car leaves the heaviest carbon footprint of the three, at least within the context of Germany's energy mix.

Which car model causes the most CO2?
Ifo used the EU's NEDC (New European Driving Cycle) standard setting emissions from driving at 83 grams per kilometer (133.5 g/mile) for the Tesla Model 3, 117 g/km for the Mercedes diesel and 76 g/km for the Mercedes LNG. NEDC was replaced in 2018 by the WLTP standard, measuring emissions more accurately and meaning they are higher for all models

It's the battery!

The study calculated that making an electric vehicle and a conventional combustion engine car creates more or less the same amount of CO2 — 8.6 tons per car. About 4.9 tons needed to produce the body of a car and 1.9 tons emitted during the assembly process.

Moreover, the study has found that producing a diesel motor causes slightly higher emissions (0.8 tons) than making the electric motors (0.3 tons) driving the Tesla 3. But while the Tesla's "additional components" account for 1.5 tons of CO2 per car, those of the Mercedes 220d create just 1 ton, the study claims.

Regarding so-called well-to-tank emissions of fossil fuels, the study uses an analysis done by the European Commission itself.

Most significant for the comparison though, is the footprint of EV battery production and recycling. There, ifo used the figures provided by a 2017 Swedish study into the energy required to produce lithium-ion batteries for cars.

Breakdown of CO2 emissions by car

The German energy mix/mess

The fact that the carbon count tips clearly in favor of combustion engines is primarily the result of Germany's fossil-fuel-heavy energy production, the researchers however say. While Norway's energy production for example relies heavily on renewable energy from water power  — which may give the Tesla 3 a carbon lead over its Mercedes rivals — that's not the case given Germany's energy mix.

In the opinion of the researchers, Germany's dirty energy situation isn't going to change over the next five years. Due to a government decision to completely phase out nuclear energy by 2022, about 76 terawatt-hours (tWh) of power need to be replaced annually.

Since this shortfall is planned to be covered by power from fossil fuels, mainly natural gas, Germany's energy mix is set to become even dirtier. Should hard coal be used as a replacement, the study calculated, the carbon footprint of a Tesla 3 EV would even spike to 175 to 200 g/km — roughly 25% more than the emissions of the Mercedes diesel and more than double that of the LNG car.

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Germany wants to cover the nuclear shortfall with renewable power as quickly as possible, and aims to increase energy from green sources to about 85% by 2050. But the researchers argue that under the current pace of the renewables buildup of 15 tWh annually, making up for the nuclear phaseout alone will take at least until 2025.

They also claim a carbon-neutral German energy production might turn out to be both technically unfeasible and economically unviable. 


The study, naturally, invited a strong backlash from e-mobility proponents, who strongly questioned the findings. The Fraunhofer ISI think tank, a renowned research group advocating e-mobility, criticised the use of the Tesla 3 as a reference model, arguing the car's battery was too powerful to be used as an example for average car CO2 measurements. 

In a response issued on Tuesday, Fraunhofer ISI also said ifo had used the outdated NEDC standard for measuring the Mercedes' fuel consumption, which in real driving situations, measured by the new WLTP standard, was much higher. This point, however, could also be raised with the 15 kilowatt-hours per 100 kilometers (15 kWh/93 miles) that Tesla touts for its Model 3. Road testing by the German newspaper FAZ suggests this is actually around 24 kWh/100km. 

Another criticism concerned the carbon data from battery production, which was allegedly too high. Critics says ifo hadn't given due regard to the renewables buildup planned in Germany, which would make electric car charging ever more greener in the decade ahead. 

On Wednesday, German carmaker Volkswagen, which wants to sell 10 million EVs in the coming years, also stepped into the fray. It admitted that under current German energy conditions its fully-electric Golf would emit 142 g/km over a life cycle of 200,000 kilometers, while a diesel-driven car of the same type would create only 140 g/km. But VW also noted that using the European energy mix for calculations, which includes large amounts of nuclear energy from France and water power from Norway, the e-Golf's carbon footprint would be down to 119 g/km.

In view of the controversy, ifo's researchers argue their study should not be seen as a complete piece of scientific research into electromobility's carbon footprint. Yet, they are sticking to their judgement that the electric car is not a panacea in the fight against climate change.

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