Electric car batteries major source of CO2
By Johan Kristensson
Enormous hope has been placed in electric cars being a solution to climate change. However, manufacture of batteries for electric cars is not especially environmentally friendly. Several tonnes of carbon dioxide are released, even before electric batteries leave the factory.
IVL, the Swedish Environment Institute has, on behalf of the Swedish Transport Administration and the Swedish Energy Agency, investigated the climate impact of lithiumion batteries from a life-cycle perspective. Batteries for electric cars were included in the study. Lisbeth Dahllöf and Mia Romare produced a meta-analysis, that is, a review and compilation of existing studies.
The report shows that battery manufacturing leads to high CO2 emissions. For each kilowatt-hour storage capacity in the battery, emissions of 150 to 200 kilograms of carbon dioxide equivalent are generated, in the factory. The researchers have not studied the batteries of individual car brands, just how they were produced or what electrical mix they used. But to understand the importance of battery size here’s an example: two standard electric cars on the market, Nissan Leaf and Tesla Model S, have batteries of approximately 30 kWh and 100 kWh respectively.
As soon as you buy one or the other, CO2 emissions of approximately 5.3 tonnes and 17.5 tonnes, have already been released. By way of comparison, a person returning from Stockholm to New York by air creates emissions of around 600 kilograms of carbon dioxide, according to the UN organization ICAO’s calculation model.
Another conclusion of the study is that nearly half of the emissions occur during the production of the raw materials and close to half during the production of the battery in the factory. The mining itself accounts for only a small part of between 10-20 percent.
The calculation was based on the assumption that the electricity mix used by the battery plant is more than half generated by fossil fuels. Though in Sweden, power generation predominantly consists of zero-carbon nuclear and hydropower, so as a result, lower emissions can be achieved.
The study also reveals that CO2 emissions rise almost linearly with battery size, even though data is scarcer in this area. This means that a Tesla-size battery contributes more than three times as much CO2 as a Nissan Leaf’s battery. It is a result that surprised Mia Romare “It should have been less linear because the electronics used do not increase to the same extent. But the battery cells themselves are as influential as the production,” she says.
The authors emphasise that a large part of their study was about finding out what data was available and, in many cases,, they found it was difficult to compare existing studies with each other.
A colleague at IVL, Mats-Ola Larsson, has calculated how long you need to drive a petrol or diesel car before it has released as much carbon dioxide as just the manufacture of an electric car battery. The result was 2.7 years for a battery of the same size as a Nissan Leaf and 8.2 years for a Tesla size battery.
“It’s great for companies and government to embark on ambitious environmental policies to buy climate-smart cars. But these results show that one should not think of choosing an electric car with a larger battery than necessary,” he says.
The authors of the report also note that there is still a lack of financial incentives to send the exhausted batteries for recycling. Cobalt, nickel and copper are recycled, but not the energy required to make the electrodes, says Mia Romare.
- Courtesy of the Global Warming Policy Forum
That piece was reproduced from “Wheel Torque”, the regular newsletter of the NZ Federation of Motoring Clubs, Issue 27, Feb-March 2018. Electric cars: A green solution? Perhaps not quite as green as the messianic lobbyists and the media would have us believe…?
There are other problems. The ‘NZ Listener Mar 31 – April 6 2018’ issue ran a lengthy article by Peter Griffin on problems appearing with some of these cars. “The Nissan Leaf is the world’s bestselling electric car. Over 300,000 of them have been bought worldwide since the Leaf’s debut in 2011. Of the 5022 new and used electric vehicles registered in New Zealand at the end of February, over half were used Leafs.”
One owner, Dave Hawkins, took his newly-purchased second-hand 2016 Leaf on a test drive around Christchurch, where the ‘state of health’ of its 30 kilowatt-hour (kWh) battery – a measure of its ability to hold energy – was at 97%. A few days later when he checked again, it was down to 94%.
“Fairly rapidly over the next month, it kept going down,” says Hawkins. “By the time it was past 90%, I contacted the dealer and told them what was going on.”
The dealer opted to give him his money back in full and the story could have ended there. But Hawkins also contributed his Leaf’s battery health statistics to a New Zealand citizen science project called Flip the Fleet.
Last week, in what the authors believe is a world first, the Flip the Fleet team published online a study examining the battery state of health results from 283 Nissan Leafs, using data gathered from Leaf owners around the country.
The results, claims Flip the Fleet co-founder and University of Otago emeritus professor Henrik Moller, are alarming. The researchers found that the 30kWh models of the Leaf, which went on sale in 2016 and offers greater driving range than the 24kWh version, was rapidly declining in its ability to hold electric charge. “By two years, the 30kWh vehicles are dropping their ability to hold energy by about 10% per year,” says Moller. “The 24kWh Leafs are dropping at 3% per year.”
Nissan estimates that the battery on the 30kWh Leaf should reach about 80% of its energy-holding capacity after five years of use. But Moller’s team were seeing them reach that point in just over two years. Even worse, the rate of decline appears to be accelerating as the batteries get older. It remains a mystery as to why this is happening, though theories abound.
Despite the popularity of the Leaf in New Zealand, Nissan doesn’t sell them new here after it pulled the 24kWh version out of the market in 2015. It means that the thousands of New Zealand owners of second-hand Leafs have no official channel to buy a replacement battery for their car, which is starting to become an issue as seven-year-old first generation Leafs approach the end of their useful battery life. A new 30kWh battery and installation costs $9,000 in Japan.
In the words of the ancient Romans: “Caveat Emptor”…