We need to measure the total lifecycle emissions of cars – but EVs still win

Towards the end of 2020, a highly controversial report was circulating in the UK and receiving wide coverage in newspapers (albeit mainly on the right). It became known as #AstonGate, referring to the main company behind the report (which had tried to hide its involvement). The resulting backlash did not reflect well on the people involved, but it did signal something positive. We can’t just consider tailpipe emissions, nor can we just consider a vehicle’s fuel source emissions. We must also consider the environmental impact of production – and disposal/recycling of end-of-life vehicles. Only then can we truly know which type of car is more environmentally friendly.

Electric vehicles produce more carbon during production, mainly due to the battery. But it’s difficult to accurately calculate lifetime emissions because there are so many variables to balance. Many attempts fail. In the last month or so, a TEDx talk posted on YouTube in early 2020 has also started circulating, seemingly weaponized by those who would attack the green credentials of electric vehicles. Titled “The Contradictions of Battery-Powered Vehicles” and presented by Dr. Graham Conway (who works at the Southwest Research Institute, founded by oil tycoon Tom Slick), the presentation sounds pretty compelling. But it also contains a lot of flaws.

The first problem is that Conway does not cite where he gets his numbers from. That doesn’t necessarily mean they’re not true, but without sources it’s impossible to know, and many numbers don’t appear to be correct. Conway’s basic principle of counting total CO2 and not just exhaust emissions is completely valid. But the devil is in the details, and many details of the presentation raise questions.

Conway’s first argument comparing Corvettes to horses is easy. Animals are not part of a purely circular CO2 life cycle. We need to seriously reconsider the amount of beef we eat due to the methane production of cows. In fact, according to the Food and Agriculture Organization of the United Nations, 14.5% of all CO2 produced by humans comes from livestock. Not everything goes back to the plants that livestock eat. Some of it ends up in the atmosphere and contributes to global warming. Conway argues that horses provide 100% circularity, and he’s wrong.

Conway also says, “a lot of our electricity comes from coal,” which really depends on the country. In 2020, Australia derived around 54% of its electricity from coal, 20% from natural gas and 2% from oil, for a total of 76% from fossil fuels. However, in the United States in 2021, coal consumption was much less – only 18%, including 43% natural gas and 2% oil, for 63% fossil fuels. By contrast, in the UK, 54.1% of electricity came from low-carbon sources in 2021, and almost none from coal.

Conway paints a more negative picture than the current truth. Many other countries still use a lot of coal – India, for example. But the percentages are falling rapidly. Conway acknowledges this, but his figure of 67% of the world’s electricity coming from CO2-producing sources is already exceeded. Ember put it at 62% for 2021, and we can’t verify where Conway got his number from because he doesn’t say. Not a huge difference at 67%, but the numbers are dropping (almost) every year.

Another figure he doesn’t show a source for is the average lifespan of a vehicle, which he puts at 180,000 miles. That seems like a lot if you’ve tried driving a car with that many miles, though it at least uses that number equally for EVs and fossil fuel cars. However, he states that an average vehicle produces 30 tonnes of CO2 over that 180,000 mile lifespan, which equates to 167g per mile. That’s a huge underestimate, when you consider that the average new car in 2021 in the UK was producing 185.9g, and the majority of cars in the world aren’t new. According to the US Environmental Protection Agency, in America the average was more like 404g CO2 per mile, more than double Conway’s figures. Again, it would be nice to know where his data comes from.

However, these exhaust CO2 averages don’t account for CO2 from fossil fuel production (and clearly Conway doesn’t either). Auke Hoekstra, Senior e-Mobility Advisor at the Technical University of Eindhoven, calculated that you should add 30% for petrol and 24% for diesel to the exhaust CO2 of an internal combustion engine car. So this average new British car actually emits 242g per mile, and the average American car 525g per mile.

The lifetime CO2 figure for an EV in Conway’s video appears to be around 18 tonnes for 180,000 miles. Since we are global, let’s also test this number globally. According to the IEA, in 2018 the global average carbon intensity of one kWh of electricity was 475g. Most electric vehicles can travel at least 3 miles per kWh on average. That means a typical electric vehicle would produce 158g of CO2 per mile from charging on the global grid in 2018, or 28.5 tonnes over 180,000 miles, so his figure of 18 tonnes is an underestimate. . But for the same mileage, an average American car would produce nearly 95 tons, more than three times as much.

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

That’s not so significant compared to how wildly incorrect Conway’s lifetime CO2 figures for fossil fuel cars and electric vehicles are. You won’t need to drive an electric vehicle 80-90,000 miles before its CO2 emissions drop below that of a fossil fuel car. Even using the global network, the figure will be 15-20,000 miles, and networks will get cleaner and cleaner during this time, so it’s likely to be much less in the future. If you drive your EV in a country with a relatively clean network like the UK, the distance will be less now.

Obviously, the bigger the car battery, the more CO2 it takes to manufacture it. Conway says his point about the EV lineup is “where it gets interesting,” but that’s really where he shows how wrong his numbers are. It seems to claim that an electric vehicle with a range of 400 miles will create 25 tons of CO2 during production. But the 75 kWh battery in a Tesla Model 3 Long Range – which has a range of 358 EPA miles and a range of 374 WLTP miles – produces 4.5 tonnes of CO2 if manufactured at Tesla’s battery factory. in Nevada, and still only 7.5 tons if produced in Asia. . It will therefore not be 25 tons in total for the overall manufacture of the vehicle. The worst-case scenario will be 12.5 tons, and probably even less than 10 tons if made in America, so over its lifetime the electric vehicle will beat the emissions of a conventional car very quickly.

There are a few valid points in Conway’s speech. His argument that the problem of climate change is global and that electric vehicles won’t suit some countries deserves serious consideration, and his belief in the need to embrace renewable energy is genuine. It’s also fair to say that electric vehicle production may decline as renewables proliferate. The problem is the timescale he cites. We are not trillions of dollars and decades away from achieving this. Some countries are lagging behind, but as I write this article, around 75% of the UK’s energy comes from wind, solar, nuclear and other low-carbon sources.

The final mistake is when Conway concludes that the real solution is hybrids. They are more efficient than non-hybrids, but not enough to make up for 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, or 34% more. One-third more efficiency won’t make up for the huge lifetime CO2 difference compared to an electric vehicle.

We really shouldn’t continue to invest in the internal combustion engine. Although it’s been valuable in mainstream markets for a decade or two, its days are numbered in the developed world and we can’t do enough to improve its effectiveness. Another source of wasted energy is renewable fuels. If you want to have an effect on global emissions now, buy an EV, not a hybrid.

#measure #total #lifecycle #emissions #cars #EVs #win

Add Comment