A recently published study by Swedish environmental research and consultancy firm IVL Svenska Miljöinstitutet highlights the environmental impact of electric cars as a result, amongst others, of CO2 emissions from the manufacture of batteries. The media have picked up on IVL's study and some have even called electric cars "environmental villains".
IVL's literature review focuses on a fact that, so far, has barely featured in the debate around the environmental characteristics of electric cars, i.e. the significant emissions of CO2 currently generated by the production of lithium batteries for electric cars. This means that electric cars effectively have a "climate deficit" compared with diesel or petrol driven cars: according to the report, every kilowatt hour of battery gives rise to emissions of 150-200 kg of CO2 equivalents.
"It's true that new electric cars with the current lithium batteries have a degree of "climate deficit" from the outset. But if you take the lifecycle of the car as a whole, electric cars emit far less CO2 than diesel and petrol driven cars, especially in Sweden, where the electricity mix is considerably cleaner than it is in continental Europe," says Vattenfall's Head of Environment, Helle Herk-Hansen.
According to a study commissioned by Vattenfall from consultancy firm Ramböll, there is a major difference in the typical lifecycle emissions of C02 equivalents between different types of cars (including extraction of raw materials, manufacture, use, servicing and recycling). On average, a petrol car produces CO2 emissions of 250 g/km, a diesel car 200 g/km and an electric car in continental Europe an average of 190 g/km, while an electric car that is used in Sweden produces only 70 g/km. The calculation was based on a battery size of 24 kWh*, which is equivalent to a Nissan Leaf or Renault Zoe that is a few years old.
Emissions from battery production
The batteries in electric cars have a major impact on the overall carbon footprint from car production. Most of today's electric cars have lithium ion batteries that, until now, have primarily been manufactured in Asia, where much of the electricity is still generated by coal-fired power plants, although the proportion of renewable electricity generation is increasing.
A number of car manufacturers, including Tesla and Mercedes, have started building their own battery plants, amongst others to improve the environmental performance of electric cars. US company Tesla's Gigafactory battery plant in the state of Nevada, for example, will be powered entirely by renewable electricity from solar panels. As a result, the carbon footprint of Tesla cars, which have the largest batteries on the market, will be significantly reduced in the future.
The newly launched Swedish company Northvolt, in which Vattenfall has a minority stake, plans to build a brand new battery plant in Sweden or Finland. Once the batteries are produced using clean electricity derived from hydro power, the carbon footprint of the electric car will be less than that of the electric cars of today or yesterday.
Reuse of batteries
There are also other ways of reducing the carbon footprint of electric car batteries. Lithium ion batteries lose some of their storage capacity over time but they can still be used for storing energy in the electricity grid for quite a few years. This is done by connecting a large number of batteries to large battery packs which can stabilise the electricity grid and supply electricity when electricity generation from wind and solar power is low.
"We have a partnership with the car manufacturer BMW in Hamburg, called Second Life, in which we reuse batteries from BMW's electric cars to store renewable electricity. We also plan to purchase up to 1,000 lithium ion batteries to stabilise and balance the electricity grids in conjunction with wind farms. The Dutch wind farm Princess Alexia is one of the wind farms that has been equipped with batteries to improve the quality of the electricity grid," says Herk-Hansen.
The carbon footprint and environmental impact of batteries will also be reduced by recycling them wherever possible. Currently only the most valuable metals, nickel, cobalt and copper are recycled, not aluminium and lithium, for example.
"As the number of batteries increases, it's crucial that the recycling of metals is financially viable. This is something that the battery industry must guarantee in order to reduce the environmental impact of electric cars and other battery-powered products," says Herk-Hansen.
Vattenfall invests in electric cars
According to Herk-Hansen, ongoing electrification of the transport sector is crucial. She also welcomes the fact that Vattenfall is driving this transition process.
"It's great that Vattenfall plans to convert its entire vehicle fleet to electric vehicles. In spite of the environmental "deficit" caused by the production process, electric cars are a better environmental choice than fossil-powered cars. And they also have the potential to be even more environmentally friendly, whereas cars with combustion engines have less potential," says Herk-Hansen.
In Europe, road traffic accounts for around 20 per cent of CO2 emissions, while in Sweden this figure is around 30 per cent. Private cars are responsible for around two-thirds of these emissions. Many people believe that the electrification of road traffic has great potential to reduce the CO2 emissions from this sector, which is still heavily dependent on fossil fuels.
* Renault Zoe now has a new generation of more efficient batteries whose capacity has been increased by 80 per cent from 24 to 41 kWh, while their weight has increased by only five per cent.