I found this interesting article, which seems a pretty thorough study:
Coal motors, wind engines and diesel engines: what does the CO2 balance show?
It is in German, but with the assistance of Google Translate (astonishingly good) as preparation, and my own corrections as a native German speaker of the result on top of it, I translated a few key paragraphs. Apologies if some things are still not clear, I only spent a limited amount of time on this.
About the Authors:
Christoph Buchal is a professor of physics at the University of Cologne and a researcher at Forschungszentrum Jülich. Hans-Dieter Karl was employed as a specialist in energy research at the Ifo Institute, and Hans-Werner Sinn is professor emeritus at the Ludwig-Maximilians-Universität München and former President of the Ifo Institute. None of the authors has a commercial relationship with the energy industry or auto companies. The authors thank Karen Pittel of the Ifo Institute for useful information and Daniel Weishaar for a thorough research assistance.
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Summary:
Based on official measurement data, this article compares two midrange cars, the Mercedes C 220 d and the new Tesla Model 3, in terms of their consumption of diesel or electricity. This will be based on alternative marginal energy sources for electricity as well as Germany's actual electricity mix from 2018. Furthermore, a meta-study on CO2 emissions in battery production is taken into account. It turns out that the CO2 emission of the electric motor is about one-tenth and, in the unfavorable case, about a good quarter higher than the output of the diesel engine. The least emitting is the combustion engine powered by methane, which is almost a third lower than the diesel engine, even if one takes into account the considerable pre-pollution by methane production. There are two advantages to using hydrogen-methane technology. On the one hand, in the long term, it is the only way to store the surplus peak wind and solar power required to expand the market share of this form of renewable electricity. On the other hand, even as is, it offers the possibility of considerable CO2 savings, even if this methane comes from fossil sources.
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1.
An analysis of the current situation of the energy turnaround shows that, despite high annual investments, above all in the area of »renewable electricity production«, the total German CO2 emissions do not fall as much as anticipated. In the transport sector in particular, virtually unchanged emission totals have been observed for many years, although the Federal Government has set a reduction target of at least 40% for this sector by 2030 (see Federal Ministry for the Environment, Nature Conservation and Nuclear Safety 2016). P. 8).
That is why the transport sector is currently being criticized for its unabated fuel needs. Although an effective move away from gasoline and diesel is obviously very difficult, politics and the media public still have high hopes for a more rapid introduction of electric cars. Above all, politics justifies this step with effective climate protection which should be achieved by reducing the petroleum demand for gasoline and diesel. This would also mean that the CO emissions proportions fall proportionally.
Now, you can definitely welcome the turnaround to the electric car from an engineering point of view, because it is elegant, sturdy, powerful, drives quietly and does not need a complicated gearbox. The electric car offers great potential, especially for urban traffic, because emissions are being shifted from the cities to the power plants. China is making very consistent efforts to make its giant metropolises more habitable with electric cars. Above all, the urban fine particulate matter and nitrogen oxide emissions from traffic are partly responsible for the often unbearable smog. Electric railways and vehicles offer a significant improvement in this respect. As a result, China is currently developing into the globally important market for electric cars and buses. Here, the German industry should not lose touch.
However, it cannot be claimed that electric cars can be moved without CO2 emissions, as the European legislator claims if it allows the CO2 emissions of these cars to be included in its calculations with a value of "zero". Such a value does not even apply to Norway, where electricity is generated almost zero-emission with hydropower, because the CO2 emissions are ignored in the production of vehicle and battery. Moreover, in all other European countries high CO2 emissions result from the charging of the batteries with the help of electricity from the respective national production mix of green energy and nuclear energy on the one hand and fossil fuels on the other.
In the following, therefore, we will first provide an overview of the situation of German electricity production in order to be able to compare electric cars with burners, in particular diesel, with regard to CO2 emissions in the following chapter. Of course, it does not matter where the CO2 emissions are generated, whether distributed by the vehicles or concentrated in the power plant, for the CO2 balance and the climate problem.
For comparison, we consider the CO2 emissions of a modern diesel vehicle with that of a modern electric car based on two concrete examples for which the measured values are available to us. On the one hand there is the Mercedes C 220 d and on the other the new Model 3 from Tesla. Both vehicles have a similar size and are in the same vehicle class. We use the official NEDC values for energy consumption and CO2 emissions. As far as possible, we also make further comments on the upstream and downstream CO2 balance sheets.
We explain the current state of the facts in such detail because in the postulated complete emission freedom of e-cars we suspect a purposeful industrial policy deception and consequently fear an inevitable disappointment of the public if the hoped-for technical CO2 reductions do not materialize. This will be explained in more detail in the concluding remarks.
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7. Concluding Remarks
It follows from our comparative calculations for the new Tesla Model 3 and the Mercedes C 220 d that even modern electric cars will hardly be able to contribute to the reduction of German CO2 emissions in the coming years. Unfortunately, due to our grid situation, electric cars are still premature for this strategic goal in the sense of German climate protection efforts. It cannot be claimed that the introduction of electric cars in itself will lead to a reduction in CO2 emissions in transport, as suggested by the EU Directive on the calculation of fleet consumption, which includes electric vehicles CO2 emissions from zero. The opposite is the case. The CO2 emissions of the battery-electric cars only in the best case lie on a comparable level with the diesel engine value, considering today's energy mix in Germany and taking into account the energy costs of battery production.
Modifications of this statement are only possible if it is possible to operate the electric cars to a greater extent with low-emission energy than corresponds to today's average. If one assumes a rigid handling of the emissions trading, then it may be so. Then, however, the electric cars will cause other electricity consumers to be ousted from the market by drastic price rises in emissions allowances and electricity. The withdrawal of energy intensive manufacturing industries will be unavoidable. Resistances of consumers and / or taxpayers are inevitable. Since Germany already has the highest electricity costs in Europe today, we do not consider the case of rigid handling of emissions trading to be particularly plausible, especially also since nuclear power plants are planned to be shut down. It is likely that emissions trading will be handled more flexibly and that conventional electricity generated from fossil sources will be used more extensively than originally planned in a transitional period. Then the electric cars could temporarily become hidden coal or natural gas cars. The CO2 emissions from the power stations 'chimneys, which are also caused by electric cars, do not appear in the EU formula for manufacturers' fleet consumption, because the CO2 emissions of electric cars are set at zero, as if especially this stream always come from green sources. This formula is misleading the population, even though its creators presumably had no illusions about CO2 emissions from electricity production.
