The carbon footprint of the most common type of battery for electric cars is estimated to be 61-106kg of CO2 emissions equivalent per kilowatt hour of battery capacity, according to the latest data compiled and modelled by battery researchers at IVL Sweden. This is 2 to 3 times lower than the 150-200kg of CO2eq estimate measured by the same researchers back in 2017. The 2017 study has been used several times by anti-EV commentators to discredit the climate performance of EVs.
There are three main reasons why the production of the battery, known as Nickel Manganese Cobalt chemistry (NMC), has improved so rapidly. First, the commercialisation and scaling up of battery cell manufacturing has brought efficiency in terms of less energy per cell needed and therefore a drop in CO2 emissions. Second, more recent and accurate data has become available to populate the model, instead of it relying on old assumptions and outdated info. Third and last, electricity generation in key manufacturing regions is using more and more renewables, decarbonising the grid and reducing emissions from manufacturing, especially in Europe, the US and China.
The lower end of the estimate, 61kg – with a high renewable electricity mix – is very close to what other authoritative sources measured in 2019 such as the study prepared for the European Commission (77 kgCO2/kWh) and the much cited Argonne National Lab study (65 kgCO2/kWh). In fact, the large range of the estimate is mainly dependant on the energy mix used to manufacture batteries.
The Swedish researchers themselves mentioned that the higher end is unlikely in the real world as it assumes that the heat needed for battery manufacturing is generated by coal-based electricity whereas in reality a more efficient natural gas heating is used.
Lucien Mathieu, emobility analyst with Transport & Environment, said: ‘EV batteries are getting cleaner and cleaner by the month. This is because production is becoming more efficient with the scale and because the energy mix to manufacture is decarbonising. So it does matter where the factory gets produced. This supports the current Commission push to establish a battery cell industry in our continent via the EU Battery Alliance.”
‘The new study also acknowledges that accurate data is a challenge. So the upcoming EU battery regulations should establish a robust database and require companies to report accurate carbon footprint data. Data on metals supply chains is a particular problem. Thus the need for traceability and binding due diligence so that sustainable and responsible production is ensured,’ Lucien Mathieu concluded.
The 2017 study from IVL Sweden was used & misused by many to exaggerate the climate impacts of battery production when doing the lifecycle analysis (LCA) of electric cars. Controversial figures such as the multifaceted German economics professor Hans-Werner Sinn used the old study to base his damning conclusions about EVs. A good rebuttal was written as a follow up in Guardian