Comparing emissions of electric cars with petrol cars

Edit: New readers to this topic can read the 8 dated posts onward, or join at post 9 of 11 April 2022.

Has anyone figured out which gives the greater environmental impact of these alternatives, given that the infrastructure exists:

  1. Petrol (or diesel) engine car: fuel usage about 20% efficient. Emissions during exploration, drilling, pumping of the crude oil, transporting it to refinery, refining, then shipping and road transport of the product to service stations.

  2. Charging an electric car using coal sourced power off the grid.Usage efficiency in car near 100%. Emissions from power generation, losses in transmission from power plant to home.

(Charging from your own solar system obviously the go, but I think less used)

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Yes there was a comparison done about Electric Vehicles vs Petroleum and in some states the Electric was less efficient CO2 wise than the “Petro” ones Vic being one state. I will look for the link later to see if I can put it in here.

Found two of the links:

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@grahroll. There has been much hysteria over claims about electric vehicles and in most countries, the charging of the vehicle results in CO2 emissions elsewhere (and not direct from the exhaust pipe).

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No disagreement there. In fact my links, I think, point out that EV use can be a worse outcome if charging from the grid. It depends on what is being used to power that grid and so for example it is better to charge off the grid in Tas as a lot of power is produced from hydro and similar. In NSW, Qld and Vic it is a poorer choice to charge from the grid due to the use of Coal.

If PV panels are used EVs are the way to go even with their inherent Carbon cost due to manufacture.

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Thank you for those links.

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As Vic moves to more Renewable sources the carbon footprint of Electric Vehicles become a better enviromental choice there than petrochemical powered ones. Oh what a difference a year or two makes :slight_smile:

On another topic there is a debate about hydrogen & fuel cell tech cars/vehicles. This tech of course has benefits over Lithium cells and similar, particularly in end of life recycling. Also of benefit is the relative ease of access to the primary component used to make the fuel, water. Still storage safety can be a huge issue for this extremely flammable & easily ignited gas. Every tech has benefits and issues but in all but a few isolated circumstances they all handily beat fossil fuel cars.

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Embodied emergy to make the vehicle is also a very important consideration qhen comparing electric vehicles with conventional vehicles.

As outlined in my post on petrol prices…

the embodied energy for a Telsa Model S would take over 8 years of normal/average operation to recoup the additional CO2s generated by the electric system in these vehicles (EVs with smaller battery stystems or hybrids woukd have shorter recoup periods). From then on, one would start to be in front in relation to CO2 emissions when compared to a conventional/regular similiar sized vehicle.

If the batteries have a life say of 15 years (can’t find on the Telsa website expected battery life to replacement), then there would be about 7 years (assuming the electric car lasts 15 years) of positive CO2 reductions. Using renewable electricity over fossil fuel sources would have higher potentiak savings (noting the later source could potentially result in higher ongoing CO2 emissions).

I also understand the a significant part of the cost premium in electric vehicles such as Telsa and others is due to the high energy requirement to produce these vehicles (from cradle to operational).

If renewables or nuclear are used for lithium refining and battery manufacturing, it would would potentially reduce the embodied energy and the 8+ year period. It would never be zero as the additional energy required to manufacture the renewable energy systems/nuclear would also need consideration and the mining and transportation energy costs are unlikely to reduce in the short to medium term.

Interestingly in China research has been done into this GHG (Green House Gas) issue and from the “Summary & Prospects” part of the paper (www.mdpi.com/2071-1050/9/4/504/pdf) is this:

“This study focused on the GHG emissions during the manufacturing of LFP, NMC, and LMO batteries, and established a GHG emissions model for lithium ion batteries in the Chinese market as based on the LCA method. As shown in the study findings, production of 28 kWh of LFP, NMC, and LMO batteries in China results in the respective GHG emissions of 3061 kgCO2-eq, 2912 kgCO2-eq, and 2705 kgCO2-eq, with LMO batteries emitting the least. Carrying the 28 kWh LFP battery will increase the GHG emissions of the whole car manufacturing process by 30%. While the car consumes electricity throughout the entire use phase and GHG emissions in the manufacturing process account for merely 5% of the whole life cycle, the impact of GHG emissions in the battery manufacturing process is not significant on the total life cycle.”

This GHG production cost was “Chiefly due to China’s higher GHG emission factor and production of anode active materials, GHG emissions from the manufacturing of lithium ion batteries in China are some three times greater than those in the U.S.” Here they are stating that most of the GHG was due to the way China uses fossil fuel to generate the energy needed. And still the total GHG component of manufacture was at a low 5%.

Based on the 8 years to offset the carbon from manufacture of an EV, then a fossil fuel car would be somewhere about 5.6 years to offset it’s manufacture (using the 30% difference). So the difference of about 2.4 years is perhaps more appropriate to the discussion in that an EV car would only need a further 2.4 years of use, as compared to a fossil fuel car, to be have paid off GHG manufacturing costs but would still be vastly ahead on daily GHG energy usage costs.

If they could attain the same GHG cost of that of the US they would have even further reduced the GHG cost of the cells by 3 times.They go into this a little in saying that “improving the electricity production structure and optimizing the production process of anode active materials can significantly lower the GHG emissions during the manufacturing of lithium ion batteries in China.”. So for GHG in China the production of Cells for cars is “not significant” to the total life cycle but still could be improved to again help reduce GHG.

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This old topic is augmented by a current news report on how EVs compare to petrol vehicles, and how the outcomes are essentially state dependent.

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