[ppf]

Some simple back-of-the-envelope maths shows that, due to the massively increased amount of energy needed to manufacture an EV, it takes somwhere near half the life of the car (assuming 100k miles) to pay back that "CO2 debt". And even then, you are still limited by the net CO2 emissions of your electricity source.

This is why I claim that the CO2 benefits are minimal (not none, or negative). The abstract of the article you linked only claims that the net CO2 of EVs and heat pumps is less, but does not indicate by how much. I would also love to see the assumptions made, especially if manufacturing energy cost is considered. Do you have a non-paywalled version of the article body?

[hokkos]

Check this site https://climobil.connecting-project.lu

It has better back-of-the-envelope maths than you could do, it use peer reviewed lifecycle data, take into account real world tank-to-weel CO2 emission from cars where NEDC and WLTP underestimate them massively, well-to-tank emission to make and transport petrol, lifecycle batteries, glider, engine and also the future decarbonation of the electric grid. It shows way better estimates than you claim.

[ppf]

Great, thanks. I just compared my family car to a somewhat equivalent EV, and it takes 40,000km to break even in CO2 emissions. This is very much in line with my original point (and my "back of the envelope maths"). In the online calculator you linked, I assumed a car life of around 150,000km, as the longevity of mass-produced EVs is yet to be determined. It also addresses none of the additional points in my original comment, as we have so far talked entirely about CO2 emissions. If it is all about CO2, and the impending climate catastrophe, then the relatively small reduction in CO2/mile from an EV is just not even close to what is needed. In the calculator linked, it's a 40% reduction per mile. An EV is not the answer. Significantly fewer travelled miles is the answer.

Edit: Just for reference, the UN is calling for a 7.6% reduction in CO2 every year for the next 10 years. Either way you calculate it, an EV alone does not acheive that goal. And if you massively reduce your miles (say, 10x), it doesn't matter (relatively speaking) if you use an EV or an ICE car.

https://www.unenvironment.org/explore-topics/climate-change/...

[hokkos]

In my country, France, it is a 4.5 times reduction, grid will continue to decarbonate, electric car have less moving part and their engine is not a self destructing explosive one, batteries max cycle continuously extends, also batteries CO2e/kWh will continue to reduce as their is better industrial process and the electric grid is being decarboned and mining vehicles switch to electric, also we continue to use less minerals to store a kWh.

Also we can both buy less car, drive less km and switch to electric when a car is needed but use more the one car with car sharing infrastructure.

[ppf]

You have a 75% nuclear-powered grid in France, so yes, that probably does work out. It is also the only practical solution if we want EVs.

I really don't buy the whole "electric cars have less moving parts" argument. As I said in my original comment - how many cars get scrapped or sold due to electrical issues, compared to ICE issues? You should know, in France ;) Replacing mechanical moving parts with integrated circuits that have features on the nanometer scale that must not move, and putting them in the harsh automotive environment, is not a step forward in reliability.

I understand that technology and processes will improve, but that's not really a good argument to invest in the technology today. Maybe I should wait, and buy an EV in a few years or decades, when the environmental impact is a lot less.

[asenk]

Actual research vs. "back-of-the-envelope maths". I'll go with the research.

[ppf]

Unless you have paid for the article and read it, we are only discussing an abstract. That isn't enough information to bring to a discussion, as we have absolutely no figures, initial assumptions, or methadologies to explore.

There's nothing wrong with back-of-the-envelope maths. It's not refutable that lithium battery packs take a lot of energy to manufacture (as well as all of the control electronics, which is also a very energy-intensive manufacturing process). Just the lithium cells take around 60kWh to manufacture per 1kWh of pack capacity. Where do you think the ~5.1MWh required to make your Tesla battery pack comes from?

Even if you had 100% renewable power to charge your car, it would take 24,000 miles just to pay back the manufacturing energy of the cells alone. Then you can start paying back the energy cost of the rest of the EV components, which are still considerable. Only after that, can you start saving the planet with your EV.

https://iopscience.iop.org/article/10.1088/2515-7620/ab5e1e

[hokkos]

There is already dozens of studies about kgCO2e/kwh for batteries, thanks for linking to a studies where it is shown that electricity use is actually lower than older studies and in line with the most recent, and all the most recent studies agreed is that the kgCO2e/kwh is decreasing fast with industrialisation making EV better than fossil cars in about 16000 km.