The demand for electric vehicles (EVs) is growing over conventional vehicles due to their low operating cost, increasing EVs related infrastructures, price reduction due to mass production, and the customer’s awareness of the environment.
Making an EV Produces 70% More Emissions Than ICE, Says Volvo. It says
“Materials production and refining, battery module production and manufacturing at Volvo Cars for a C40 Recharge results in nearly 70 percent higher GHG emissions compared to an XC40 ICE”.(1)
A recent study done by the Indian Institute of Technology (IIT) Kanpur claims Electric cars are more polluting than conventional, hybrid cars. (2) Let’s find out whether EVs are more polluting than conventional vehicles or not?
In the month of May, a total of 1.57 lakhs of EVs (including 2W,4W, and others) are sold in India. EVs do not have tailpipe emissions and also cause less noise during its running so it seems EVs do not cause any pollution to the environment. But in reality, EVs are not completely eco-friendly and in this article, we will see how much cleaner it is as compared to conventional vehicles.
How EVs cause pollution
- Operation of electric vehicles
- Manufacturing of EVs & components
Pollution Caused by EVs During its operation (driving)
As electric vehicles need no petroleum fuels for their operation rather it uses batteries to drive its propulsion systems. EVs have zero emission of harmful gases like NOx, SOx, CO, and CO2 during their driving time. But still, EVs have an indirect link with the pollutants emitted from them.
Source of electricity generation-
Electric vehicles use electricity to charge the battery which is used to power the motor to run the vehicle. Electricity can be generated using coal, natural gas, nuclear reaction, and from renewable sources like wind, solar & more. In India, the majority of electricity is generated in thermal power plants (56.81% (237268.91 MW ) of the total electricity generation). If the electricity produced from renewable sources is more, the less amount of greenhouse gasses (GHG) emission is counted in EV operation.
The table below presents the pollutants generated from different types of vehicles and thermal power plants in percentage.
|Particulate matter (PM)
Below figure shows the pollution caused due to EVs and conventional vehicles from manufacturing to running 1,50,000 km in major countries of Europe. It is clear that the source of electricity generation greatly influences the count of pollutants caused by EVs.
Tailpipe represents emissions caused by fuels in conventional vehicles which is zero in EVs. An average electric vehicle in Europe produces 50% less life-cycle greenhouse gases over the first 150,000 kilometers of driving which can vary from 28% to 72%, depending on local electricity production. When comparing to the most efficient internal combustion engine vehicle, a typical electric car in Europe produces 29% less greenhouse gas emissions.
The same result is observed for the USA also. In Philadelphia, USA using Tesla Model S generates 90g/mile CO2 while 120 g/mile CO2 for average electricity mix in the USA which is much less than gasoline vehicles which produce 410 g/mile of CO2. Upstream emission represents emission caused production of fuels (in case of EV it is electricity) while Tailpipe Emission is the emission coming out of the vehicle during its running.
EVs have comparatively fewer moving parts as compared to conventional vehicles which require regular oiling and may produce fine particles in air. This also reduces the wear and tear of the parts hence reducing the aftermarket product wastes. EVs have motors (like BLDC, PMSM, SynRM) to drive vehicle that makes no noise (very negligible) on the road, unlike combustion engines.
Pollution from Brake and Tyres
Conventional Internal Combustion Engines (ICEs) use disc brakes while EVs use “regenerative braking” that restores braking energy back to the car’s battery to power the car which reduces the use of brakes. Vacuum barking is also underway to be implemented in vehicles which will further reduce particle emissions. Therefore, it reduces particle emissions in the air which cause respiratory problems and premature death.
Although EVs are heavier in weight which increases the braking distance and wear of the tyre but due to use of special tyres, this problem has a minor effect on pollution causing.
Manufacturing of EVs & components
This is the major part of EV pollution caused in the manufacturing battery contributes 31-46% of the total pollution caused. Batteries of electric vehicle batteries contain many rare and toxic metals like cobalt which are difficult to mine. In research, it is found that 30 to 494 kg CO2-equivalent per kWh is produced in the manufacturing of batteries. This is further narrowed to 61–106 kg/kWh CO2-equivalent due to more clear data.
Li-ion batteries are mainly used in EVs that consist of anode active material, cathode, electrolyte, separators, and binders. For the same capacity of Li-ion battery, LFP based-Li-ion battery produces more GHG than NMC and LMO based-Li-ion batteries. The productions of cathode materials and wrought aluminum are the dominating contributors to GHG emissions. The battery’s component mass percentage required in the manufacturing is as following in the below table:
About 50% of the battery lifetime emissions come from the source of electricity used in its manufacturing and assembling. So batteries produced from a plant that is powered by renewable energy adds a lesser amount of GHG emissions from EVs running. So many Li-ion battery manufacturing gigafactories are installing renewable energy sources to meet the power required by the plant, e.g. Tesla Gigafactory.
The difference in emissions of GHG from manufacturing of Li-ion batteries including its related components (like BMS) for China and the USA is very well shown in the below figure:
Although manufacturing of EVs generates more GHG than conventional vehicles, that gets compensated in 2-3 years of running (depending upon the source of electricity used) because of zero tailpipe emissions of EVs.
Electric Vehicles’ popularity is growing continuously because of their unique features as compared to IC engines like less operating cost and being eco-friendly. The amount of pollution caused by EVs is highly debatable. The large emission of greenhouse gases during the manufacturing of EVs is a matter of concern for engineers and scientists. But it can be reduced largely in the future because of advancements in technologies involved in manufacturing and the fast acceptance of renewable energy sources in society. After studying several reports, I am sure to write EVs are causing less pollution even in the worst case of electricity generation (opting for more thermal-based power plants). In a report, it is found that in 95% of the world, driving an electric car is better for the climate than a petrol car. Therefore, in the future, the electric vehicle is meeting the requirements of environmental concerns and will help in achieving a net zero economy.