We Need To Measure Total Lifecycle Emissions For Cars – But EVs Still Win

We Need To Measure Total Lifecycle Emissions For Cars – But EVs Still Win

Towards the end of 2020, a very controversial report was circulating in the UK and receiving wide coverage in newspapers (albeit mostly the right-leaning ones). It became known as #AstonGate, referring to the main company behind the report (which had tried to hide its involvement). The resulting backlash didn’t reflect well on those involved, but it did signal something positive. We can’t just consider tailpipe emissions, and we can’t just consider the fuel source emissions of a vehicle either. We must also take the environmental impact of production into account – and vehicle disposal / recycling at end of life. Only then can we truly know which kind of car is greener.

EVs produce more carbon during their production, mostly due to the battery. But accurately calculating lifetime emissions is hard, because there are so many variables to balance. Many attempts fail. In the last month or so, a TEDx talk published on YouTube in early 2020 also began circulating, apparently weaponized by those who would like to attack the green credentials of EVs. Called “The Contradictions of Battery Operated Vehicles” and presented by Dr Graham Conway (who works at Southwest Research Institute, founded by oil magnate Tom Slick), the presentation sounds quite persuasive. But it also contains a lot of flaws.

The first issue is that Conway doesn’t cite where he gets any of his figures from. That’s not necessarily to say they aren’t true, but without sources it’s impossible to know, and many of the figures don’t seem correct. Conway’s basic premise of counting total CO2 and not just tailpipe emissions is entirely valid. But the devil is in the detail, and plenty of the details in the presentation raise questions.

Conway’s first argument comparing Corvettes to horses is facile. Animals are not part of a pure circular CO2 lifecycle. We are having to seriously reconsider how much beef we eat due to the methane output from cows. In fact, according to the Food and Agriculture Organization of the United Nations, 14.5% of all human-produced CO2 comes from livestock. It doesn’t all go back into the plants the livestock eats. Some of it ends up in the atmosphere and contributes to global warming. Conway is arguing horses provide 100% circularity, and he’s wrong.

Conway also says: “a large proportion of our electricity comes from coal”, which really depends on the country. In 2020, Australia got about 54% of its electricity from coal, another 20% from natural gas and 2% from oil, making a total of 76% from fossil fuels. However, in the US in 2021 the coal usage was much less – just 18%, with 43% from natural gas and 2% from oil, for 63% from fossil fuel. In contrast, in the UK 54.1% of electricity came from low carbon sources in 2021, and almost none from coal.

Conway is painting a more negative picture than the current truth. Lots of other countries still use a lot of coal – India, for example. But the percentages are dropping fast. Conway does acknowledge this, but his figure of 67% of the world’s global electricity coming from CO2-producing sources is already outdated. Ember put it at 62% for 2021, and we can’t check where Conway got his figure from because he doesn’t say. Not a huge difference to 67%, but the figures are going down (almost) every year.

Another figure he doesn’t show a source for is the average life of a vehicle, which he states at 180,000 miles. This sounds like a lot if you have tried driving a car with that many miles on it, although he is at least using this figure equally for both EVs and fossil fuel cars. However, he states that an average vehicle produces 30 tons of CO2 over this 180,000-mile lifetime, which equates to 167g per mile. That is a considerable underestimate, when you realize that the average new car in 2021 in the UK produced 185.9g, and the majority of cars in the world are not new. According to the US Environmental Protection Agency, in America the average was more like 404g of CO2 per mile, so over twice Conway’s figures. Here, again, it would be great to know where his data came from.

However, these tailpipe CO2 averages don’t consider the CO2 from fossil fuel production (and it’s clear that Conway hasn’t either). Senior Advisor on Electric Mobility at Eindhoven Technical University Auke Hoekstra has calculated that you should add 30% for gasoline / petrol and 24% for diesel to an internal combustion engine car’s tailpipe CO2. So that average new UK car is actually emitting 242g per mile, and the average US car a whopping 525g per mile.

The lifetime CO2 figure for an EV in Conway’s video appears to be about 18 tons for 180,000 miles. Since we’re being global, let’s test this figure globally as well. According to the IEA, in 2018 the average world carbon intensity of a kWh of electricity was 475g. Most EVs can do at least 3 miles per kWh on average. That means a typical EV would produce 158g of CO2 per mile from charging on the global grid in 2018, or 28.5 tons over 180,000 miles, so his 18-ton figure is an underestimate. But for the same mileage, an average US car would produce nearly 95 tons – over three times as much.

Conway is correct that we must add the CO2 from production at the beginning of the vehicle’s life. His figure of 6 tons for a conventional vehicle seems about right looking at other sources, although yet again he doesn’t say what his source was. However, he then claims that BEVs produce twice as much CO2 during production, which doesn’t match other sources. This also depends on where the BEV was manufactured. The Nissan Leaf produced in Sunderland, UK, produces more like 9 tons, for example.

That’s not so important compared to how wildly incorrect Conway’s lifetime CO2 figures for fossil fuel cars and EVs are, however. You won’t need to drive an EV anywhere near as far as 80-90,000 miles before its CO2 emissions become less than a fossil fuel car’s. Even using the global grid the figure is going to be 15-20,000 miles, and grids will get cleaner and cleaner during that time so it’s likely to be much less in the future. If you drive your EV in a country with a relatively clean grid like the UK, the distance will be less now.

Obviously, the bigger the car battery, the greater the CO2 required to make it. Conway claims his point about EV range is “where it gets interesting”, but it’s really where he shows how wrong his figures are. He seems to be claiming that an EV with a 400-mile range will create 25 tons of CO2 during production. But the 75kWh battery in a Tesla Model 3 Long Range – which has a 358-mile EPA range and 374-mile WLTP range – produces 4.5 tons of CO2 if manufactured in Tesla’s battery factory in Nevada, and still only 7.5 tons if produced in Asia . So it’s not going to be 25 tons in total for the vehicle’s overall manufacturing. The worst-case scenario will be 12.5 tons, and probably still under 10 tons if made in America, so over its lifetime the EV will still beat the emissions of a conventional car very quickly.

There are some valid points in Conway’s talk. His argument that the problem of climate change is global and EVs won’t fit some nations warrants serious consideration, and his belief in the need to adopt renewable energy is genuine. He is also fair in saying that EV production can go down as renewable energy proliferates. The problem is the time scale he cites. We are not trillions of dollars and decades away from achieving this. Some countries lag behind, but as I write this piece around 75% of the UK’s energy is coming from wind, solar, nuclear and other low-carbon sources.

The final error is when Conway concludes that the real solution is hybrids. They are more efficient than non-hybrids, but not by enough to make up the huge difference. A Toyota Prius is rated at 150g per mile of CO2, and a Golf 1.0 TSI is rated at 202g per mile, 34% more. A third more efficiency won’t make up the huge difference in lifetime CO2 compared to an EV.

We really shouldn’t be continuing to invest in the internal combustion engine. While it will have value in legacy markets for a decade or two to come, its days are numbered in the developed world and there isn’t enough we can do anymore to improve its efficiency. Renewable fuels are a whole different pit of wasted energy too. If you want to have an effect, right now, on global emissions – buy an EV, not a hybrid.

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