Electric car ‘hatchet job’ debunked

A study claiming that electric vehicle produce more carbon emissions than a diesel car has been promptly debunked by academics and experts in Germany, where it was published last month. The Institute for Economic Research (Ifo) was roundly criticised over its findings which were founded on a relatively high weighting of coal generation in Germany’s power mix.

The report made an apples-to-oranges comparison of a Mercedes C220 diesel to a more powerful Tesla Model 3 with a 75 kWh battery pack. It uses fuel efficiency data for the Mercedes diesel car that is based on the outdated NEDC test cycle, which has around a 40% gap with the real-world emissions. The NEDC test cycle is not used anymore in Europe – the new test (WLTP) has been in force since September last. It means the tank-to-wheel emissions of the Mercedes car over its lifetime are hugely underestimated in the study.

The report also uses data for the carbon intensity of the German electricity grid that is out of date. This is crucial as it improves considerably each year. Ifo used 650 grams of CO2 per kWh over the lifetime of the vehicle without a clear explanation why. Germany was already at 440 g/kWh in 2016 (while the EU then averaged 296 g/lWh) and it is expected to be be around 200g/kWh by 2030.

The data for carbon emissions from battery production used in the study are also outdated: they were taken as 177 kg CO2/kWh based on a since-discredited Swedish study. That Swedish study's outdated assumptions were later corrected by its authors. While data is rare and there are big disparities in terms of the method, location and process of production, the analysis being carried out for the European Commission by Ricardo this year, and seen by T&E, put the accurate average at between 65-100g/kWh.

Even Germany's largest carmaker Volkswagen felt compelled to publicly contradict the Ifo study days after its publication, giving a rare glimpse of its own lifecycle analysis based on company-specific data showing Volkswagen EVs are better than their diesels. Ifo was also under fire in the pages of Der Spiegel and industry magazine WirtschaftsWoche, which cited the study’s use of ‘pure fairytale values ​​that have nothing in common with reality’.

T&E’s executive director, William Todts, said: ‘Using discredited official figures for the fuel efficiency of diesel cars, as well as old data for the carbon intensity of Germany’s grid and the emissions from battery production, [the study] pits a Mercedes C-Class against a much more powerful Tesla Model 3. Even an internal combustion engine giant like Volkswagen now accepts the mounting evidence that EVs are cleaner in Germany and elsewhere. If anything this study highlights the need to speed up the exit from fossil fuels such as coal in our grids and diesel in our tanks.’