“Don’t trash talk EVs”: new study shows electric cars emit less than thought

A new study from Dutch electric vehicle expert Auke Hoekstra – who helpfully debunked Murdoch-pedalled myths about EV emissions in March – shows that electric cars are even better at reducing carbon emissions than previously thought, largely because older studies used outdated data on battery manufacturing.

Such reports have previously been used by naysayers to claim that electric vehicles are worse for the environment than petrol and diesel cars. Hoekstra’s new report seeks to correct that inaccurate claim.

It shows that – contrary to a wildly inaccurate and since debunked report from German Institute for Economic Research (IFO) – that the Tesla Model 3 emits less than half the carbon of the Mercedes C220D.

Even against a hybrid vehicle such as the Toyota Prius, Hoekstra shows that the emissions of a Volkswagen e-Golf amount to about half its counterpart.

Titled “Comparing the lifetime green house gas emissions of electric cars with the emissions of cars using gasoline or diesel“, the new study from Netherlands’ Eindhoven University of Technology, which also birthed 2019’s winning Bridgestone World Solar Challenge team, covers six areas that have mistakenly put lifetime emissions of electric cars as higher than necessary.

According to Hoekstra and co-author Prof Maarten Steinbuch, founder of Master Automotive Technology at Eindhoven university, part studies have not given electric vehicles enough credit where due because they have used incorrect data on emissions of battery production.

They have also underestimated battery lifetime, not included an increasingly clean grid, used of tests commissioned by battery makers, downplayed fuel emissions and excluded external factors such as greening the whole supply chain.

“The first reason our study is positive, is because negative studies all use outdated battery emissions,” said Hoekstra on Twitter.

He cites the “infamous” IFO study, which was published in 2019, but which used a 2017 report that measured the carbon output from battery making at 175kg CO2 per kilowatt hour, more than twice 2019’s 85kg CO2 per kilowatt hour.

Hoekstra also makes the point that electric cars, and the batteries that power them, last a lot longer than previously assumed.

While battery lifetimes (and therefore replacements) have been given in the past by car makers of around 150,000-160,000km, the researchers say that data shows that a battery can power 800,000km driving before it has degraded to 80% capacity.

“And indeed there are a few Tesla drivers who have now driven a million km. A well known driver in Germany had some problems at the start but has now driven 680,000 km with the latest motor and 480,000 km with the latest battery that still has 86% capacity,” the authors write.

They also makes a point on miscalculations that an electric car will be charged using the same electricity grid mix as the first year it was driven.

“Just as the electricity mix has changed dramatically over the past 20 years, it will do so again over the next 20 years,” they write.

Additionally, the less coal is dug up out of the ground, the fewer emissions will be generated from that mining activity.

“Furthermore, we must add upstream emissions of electricity because of e.g. digging up coal, electricity grid losses which we estimate to be higher than most literature at around 30%. All in all electric vehicles sold in Europe in 2020 should count on 250 g CO2eq/kWh electricity over their lifetime.”

In addition to these miscalculations, the researchers add that past “official numbers” for emissions of petrol and diesel cars have been based on outdated cycles such as the NEDC.

“Most studies that are critical of EVs still use the NECD,” write the authors, adding that even the new WLTP cycle is not accurate enough, and for that reason the new report uses “road measurements (from spritmonitor.de) and independent test measurements with a good track record (from the EPA in the US).”

“The new WLTP is supposed to be a fresh start but doesn’t address any of the aforementioned underlying problems so improvements are limited and -we fear -temporary,” write the authors.

Lastly, the study notes that tailpipe emissions of petrol and diesel vehicles should include the extraction and production of their fuels, to the tune of 30% extra for petrol and 24% for diesel.

While electric vehicles are the life breath of Hoekstra’s work, his final note is to add that “sharing smaller electric vehicles or biking is much better for the environment still.”

“Bottom line for me: don’t trash talk the electric vehicle based on conservative and outdated assumptions but use up to date scientific data and you will see it scores much better in all EU countries already,” said Hoekstra.