Released in early December, a new report from the OECD examines “non-tailpipe” particulate emissions from vehicles. A largely underestimated pollution which also concerns electric cars.
While electric cars are often touted as zero emission vehicles in use, this is not really the case in reality. Beyond the exhaust emissions, obviously zero on an electric car, other factors are a source of emissions of particles dangerous to health: brakes, tires, pavement and resuspension on the surface are the four factors highlighted in the fingered by the latest report from the Organization for Economic Co-operation and Development (OECD).
“Non-tailpipe emissions are expected to be responsible for the vast majority of fine particle emissions from road traffic in the coming years” warns the OECD, which measures and compares emissions from electric vehicles and their diesel counterparts .
The phenomenon is worrying and projection exercises established by the OECD show that “non-exhaust” particles emitted by passenger vehicles could increase considerably with the growth of the vehicle fleet. They could increase by 53.5% in the coming years, from around 0.85 million tonnes today to 1.3 million by 2030.
The weight of the batteries penalizes electricity
While on-board regenerative braking systems in electric cars can reduce brake wear, emissions from tire wear, road wear, and particulate resuspension remain a reality in electric vehicles. In some cases, they can even be higher than their thermal equivalents.
Regarding PM10 particles (diameter less than 10 µm), the results are rather favorable for electrics with emissions 5 to 19% lower than those of a thermal vehicle. This is not necessarily the case for the smallest of them, PM2.5 (≤ 2.5 µm). It’s all about the weight and size of the battery! While small electric cars would manage to emit 11-13% less PM2.5 particles than their thermal equivalents, long-range vehicles, often handicapped by their large batteries, could emit 3 to 8% more particles.
Political actions needed
“The bulk of public policy today focuses on tailpipe emissions. The others have been largely neglected “regrets the OECD, which calls on governments to take up the issue quickly. The first recommendation is to standardize the measurements of these particles. A process that would also provide a better understanding of the factors that influence the amount of particles released.
Another point raised: that of regulation. According to the OECD, the best way remains to reduce these emissions is to reduce the use of private cars by favoring other modes of transport (bus, walking, cycling, etc.) and by introducing new taxes as well as a charge. based on the distance traveled to limit usage. Because it has a direct impact on emissions, vehicle weight must also be better controlled. On this point, France is ahead of the game since it will implement a new weight penalty from January 1, 2022.
Technologically, many avenues are highlighted. For tires and braking systems, the use of new materials will help limit emissions, all linked to new and stricter international standards for manufacturers. Roads can also be improved with chemical dust collectors. Already used in some Nordic countries, they are sprayed on the road and allow particles to “bind” which reduces their ability to return in flight in the event of wind or a passing vehicle. At vehicle level, specific filtering systems can also be on board. A device that DHL has already tested in 2018 on board a StreetScooter electric utility.
Source: OECD study