Currently reading: Analysis: Just how green are electric vehicles?
CO2-intensive battery production means emissions-free travel remains a mirage
3 mins read
10 May 2019

The legislative push towards battery-powered electric vehicles has taken hold across most of the world. Indeed, the demands of the European Union’s new car fleet CO2 emissions requirements for 2025 and 2030 leave manufacturers no option but to build significant numbers of EVs in the future. 

There are also tough EV targets in place in China, forcing car firms to react. Volkswagen, scarred by the Dieselgate scandal, is going even further by taking a huge bet on mass-manufacturing EVs from next year

There’s no doubt that travelling in EVs has a smaller CO2 footprint than even the best internal combustion engine cars because the efficiency of a battery-electric drivetrain is around three times that of a normal petrol car and more than twice that of the latest Toyota Prius hybrid. 

But, ultimately, much depends on the nature of the electricity generation that is feeding the battery pack in question. Plugging in an electric car makes most environmental sense in Norway, Sweden and France, thanks to hydropower and nuclear power respectively. 

Another crucial aspect of the lifetime CO2 footprint of EVs is the energy used to manufacture the battery packs. More than one study has claimed that battery pack production consumes so much energy that it takes significant mileage before the EV has ‘worked off’ the CO2 released during its manufacturing. 

The latest study on the ‘CO2 lag’ of electric cars comes from the University of Liège in Belgium. Calculations by Professor Damien Ernst, originally commissioned by a TV show and reported by local newspaper HLN, are by far the most negative take on EVs yet. 

Using the average CO2 output of the European electricity network, Ernst concluded that an electric car using a 60kWh battery made in Europe would have to travel some 700,000 kilometres (435,000 miles) before it is “greener than an average petrol car”. However, Ernst also says that a fully renewable European grid would reduce the EV’s CO2 lag to just 30,000km (18,640 miles). 


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The story caused an expected stir in Belgium with arguments about Ernst’s calculations, which were variously adjusted to around 350,000km or, in the case of claims from professors at the Delft University of Technology, the calculation is ‘just’ 80,000km driving before the vehicle breaks even on its larger manufacturing energy footprint. 

It’s not the first time that EV battery manufacturing has been called into question. A year ago, the International Council on Clean Transportation released an in-depth report on the same issue. It summarised 10 different studies into battery manufacturing globally, all of which attempted to calculate the CO2 released. 

The results ranged from 50kg CO2/kWh to 200kg CO2/ kWh and even higher. The ICCT used a central estimate of 175kg and calculated that battery production would add 35g CO2/km to the lifetime efficiency of an electric car, assuming the battery lasted 150,000km (93,200 miles). 

The ICCT report also compared a Nissan Leaf carrying a 30kWh battery with a Peugeot 208 1.6 BlueHDi, and concluded that the Nissan has a relatively modest 30% efficiency advantage in day-to-day use. 

The IVL Swedish Environmental Research Institute came to a similar conclusion in 2017, stating that an EV with a big 100kWh battery – manufactured on a grid that was between 50-70% fossil fuel – has emitted between 15 and 20 tonnes of CO2 before it has turned a wheel. 

The IVL recommended that drivers should not buy an EV with a large battery and that it was important that future battery manufacturing was achieved with as much renewable energy as possible. 

Audi’s newly rebuilt facility near Brussels has gone down this route for its production of the new E-tron. The factory has 37,000 square metres of solar panels, said to provide 95% of its electricity, and it uses biogas to heat the plant. The E-tron’s battery is also built on site, helping to drive down its embedded levels of CO2. 

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Clearly, while EVs have a huge advantage in terms of local pollution, the whole manufacturing cycle is surprisingly energy-intensive and the day-to-day energy efficiency is not as impressive as it should be on the typical European grid. 

If building EVs wasn’t financially risky enough for car makers, demands for factories to run mostly on renewables adds significantly to the cost.

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10 May 2019

While I accept that CO2 emissions over the whole life of the vehicle, including manufacture, is really important and that it’s far from clear what the answer to this is, the second advantage is incontrovertible: zero local gaseous emissions while the vehicle is in use. Cleaning up the air in our towns and cities is just as important as reducing greenhouse gases.


10 May 2019

Totally agree, pollution at source is what is polluting our towns and cities which means every single ice car

It is far easier to clean up pollution from the one large producer than millions of mobile polluting ones.

Such a rubbish article

10 May 2019

Really sad that Autocar is printing this nonsense, particularly right after Top Gear has been putting up articles saying essentially the opposite.

There's actually *never been* a detailed lifecycle analysis of a large-batteried EV. What's been happening is that people have been looking at the CO2 emissions of manufacturing <=24kWh cars (which have been studied), such as the Focus Electric, Volt/Ampera and first-gen Leaf and e-Golf, which add around 3.4 tonnes CO2 to the manufacturing footprint, and then scale those emissions to other cars per kWh of battery capacity.

The problem is that battery energy density has doubled since these early cars, meaning today's models use half as much material per kWh. It's more accurate to measure CO2 per kilogram of battery weight. As an example of this - if you scale 3.4 tonnes of CO2 for a 24kWh Leaf to an 80.5kWh Model 3, you get 11.4 tonnes CO2. But if you scale it by the Leaf's 300kg battery pack versus the Model 3's 480kg pack, the Tesla ends up at 5.4 tonnes CO2. Less than half.

On the British mix of electricity sources, which emits 225g CO2 per kWh (plus 12% power lost between plant and socket), a 3.4mi/kWh Model 3 works off its manufacturing emissions vs a 40MPG(imp) petrol at 22,920 miles. Every mile after that, the petrol is emitting three times as much CO2.

Another problem with these cursory looks at long-range batteries is that they assume a lifetime mileage of 93,000 miles, which is less than the warranty period, let alone what surveys indicate. The average Model S owner still has over 90% battery capacity at double that mileage. Finally, they assume that battery production happens with mostly coal-powered electricity, despite the fact that two of the world's biggest battery packs, the Model 3's and the Audi's mentioned in this article, mostly use renewable energy.

10 May 2019
Aussierob wrote:

While I accept that CO2 emissions over the whole life of the vehicle, including manufacture, is really important and that it’s far from clear what the answer to this is, the second advantage is incontrovertible: zero local gaseous emissions while the vehicle is in use. Cleaning up the air in our towns and cities is just as important as reducing greenhouse gases.


Aren't you missing the point though?

NOx is not a greenhouse gas. If global warming continues to run away, there won't be a public for the public health issue to affect.

The data clearly shows that electric cars are not saving the planet, they are in fact WORSE for climate change for 1.5 years after production.

ICE cars have a clear place in the mix.

What causes NOx build up in populated areas is congestion. Politicians need to get on with building infrastructure to reduce congestion rather than penalizing motorists.

13 May 2019
What data are you referring to exactly.... Did you just make that up? Please share

10 May 2019

The article clearly states that EVs have a "huge advantage" in terms of local pollution.  My concern is that the headlong rush into EV manufacturing doesn't seem to be matched by charging infrastructure or even perhaps by electricity generation, but I'm willing to be corrected.

10 May 2019

95% of the article concerned the potential downsides of the emissions during manufacture, and in doing so just provides ammunition for the climate deniers (denyers?) and petrol heads who want to keep their old technology and be damned to the environment.


10 May 2019

 We, the generation now won’t reap the the full benefits of a clean age society, but our chldren will, so pointing out the shortcomings just now will improve, make sure we get it right.

10 May 2019
The uptake of renewables has been enormous over the last few years, and it's only becoming cheaper. As is the improved environmental impact of producing batteries, and improving the efficiency of electric motors.

ICE cars will never be as efficient, and the local pollution they produce is terrible. Try standing next to a TX4 taxi queue in London for a few minutes. It's like a gas chamber.

10 May 2019

what about Nissan Leaf batteries that have been working still well past 100k miles? And I think a few Tesla batteries have lasted 200k, 300k+. And they can be reused for domestic storage after taken out of a car. So the idea that somebody not biased assumes a battery only lasts 93200 miles for their calcs is unlikely to be true. Hence the original study is probably biased and therefore unreliable. And what about the co2 pollution in exploring for oil, drilling for it, moving to a refinery, refining it, and then transporting it to a local filling station? No mention of any of that being accounted for!


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