• lime!@feddit.nu
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    1 day ago

    I wanted to double-check my numbers so i found a reddit thread asking people how often they charge their cars, and tried to extract info from it using mistral (so take it with a grain of salt. it gave sources but i managed to close the page after screenshotting).

    transcript

    User: how many times a week do people in this reddit thread charge their cars on average? https://old.reddit.com/r/electriccars/comments/1c0ucpg/ev_owners_how_often_do_you_charge_your_ev_and_how/

    Mistral: In the Reddit thread you linked, most EV owners report charging their cars about 2–3 times per week on average. Many users mentioned plugging in their EVs at home whenever convenient, often overnight, rather than waiting for the battery to run low. Some charge daily out of habit, while others charge every few days depending on their driving needs and battery range. The majority have access to home charging, which makes frequent top-ups easy and convenient.

    Charging Frequency (from user comments):

    • About 30–40% of users charge daily, often overnight at home, regardless of battery level.
    • Another 30–40% charge 2–3 times per week, usually when their battery drops below a certain range (e.g., 100 miles or 50%).
    • The remaining 20–30% charge less frequently, such as once a week or only when needed for longer trips.

    Typical Charging Behavior:

    • Many users set their charge limit to 60–80% for daily use to preserve battery health.
    • Some Tesla owners (especially with LFP batteries) keep their cars plugged in most of the time, charging to 100% without issue.
    • Users with shorter commutes (e.g., <50 miles/day) often charge every 2–3 days, while those with longer commutes or less efficient EVs charge daily.

    Range Added per Charge:

    • Short Commutes (<50 miles/day): Many users add 50–100 miles per charge, often charging every 2–3 days.
    • Moderate Use (50–150 miles/day): Users in this group typically add 100–200 miles per session, charging daily or every other day.
    • Longer Trips or Less Frequent Charging: Some users add 150–300 miles, charging once a week or as needed.

    Summary Table (Based on Thread Comments)

    Miles Added Per Charge Frequency Mentioned Typical Use Case
    50–100 miles Common Short commutes, 2–3x/week
    100–150 miles Very common Daily commutes, overnight charge
    150–300 miles Less common Long trips, weekly charging

    Inference: Most home chargers add enough range to cover their daily driving, rarely letting the battery drop below 20–30%. The data is sufficient to infer that 50–150 miles per charge is the norm for regular use.

    User: how about car models? are there enough mentions of which model people drive that we can figure out the average number of kWhs used per capita from the added range and the size of the battery of the mentioned models?

    Mistral: The Reddit thread does mention several specific EV models, and we can use their battery sizes and the reported range added per charge to estimate average kWh used per person. Here’s what we know:

    Commonly Mentioned Models & Battery Sizes

    From the thread, the most frequently mentioned models include:

    • Tesla Model 3 (Standard/Long Range): ~50–82 kWh
    • Tesla Model Y (Standard/Long Range): ~60–81 kWh
    • Hyundai Kona Electric: ~39–64 kWh
    • Chevy Bolt: ~65 kWh
    • Ford Mustang Mach-E: ~68–98 kWh
    • Nissan Leaf: ~40–62 kWh

    Reported Range Added per Charge

    • Most users add 50–150 miles per charge.
    • A few add 150–250 miles (usually for longer trips or less frequent charging).

    Estimating kWh Used per Charge

    Using the EPA efficiency ratings (miles per kWh) for these models, we can estimate kWh used per charge:

    Model Battery Size (kWh) EPA Efficiency (mi/kWh) Reported Range Added Estimated kWh Used Per Charge
    Tesla Model 3 (LR) 82 4.1 100–150 miles 24–37 kWh
    Tesla Model Y (LR) 81 3.8 100–150 miles 26–39 kWh
    Hyundai Kona 64 3.2 50–100 miles 16–31 kWh
    Chevy Bolt 65 3.6 50–100 miles 14–28 kWh
    Ford Mach-E (ER) 98 3.0 100–150 miles 33–50 kWh
    Nissan Leaf 40–62 3.0 50–100 miles 17–33 kWh

    Note: Efficiency varies with driving conditions, but these are reasonable averages.

    Average kWh Used per Charge (Per Capita)

    • For 50–100 miles added: ~15–35 kWh per charge
    • For 100–150 miles added: ~25–50 kWh per charge

    Most users fall in the 20–40 kWh per charge range, depending on their model and daily needs.

    User: using the data on this page https://www.iea.org/reports/electricity-2025/emissions can we create a table for how much emissions each car would produce while charging in the listed regions? use the 2021 number.

    Mistral: Here is a table estimating the CO2 emissions per 100 km for common EV models when charged in different regions, using 2021 CO2 emissions per kWh data from the IEA and typical battery sizes and efficiencies:

    CO2 Emissions per 100 km for EVs by Region (2021 Data)

    Region CO2 per kWh (g) Tesla Model 3 (15 kWh/100 km) Hyundai Kona (17 kWh/100 km) Chevy Bolt (16 kWh/100 km) Ford Mach-E (18 kWh/100 km)
    European Union ~250 3.75 kg CO2 4.25 kg CO2 4.00 kg CO2 4.50 kg CO2
    United States ~380 5.70 kg CO2 6.46 kg CO2 6.08 kg CO2 6.84 kg CO2
    China ~550 8.25 kg CO2 9.35 kg CO2 8.80 kg CO2 9.90 kg CO2
    India ~700 10.50 kg CO2 11.90 kg CO2 11.20 kg CO2 12.60 kg CO2

    Notes & Assumptions

    • CO2 per kWh (2021): EU ~250g, US ~380g, China ~550g, India ~700g.
    • Energy use per 100 km: Based on EPA/real-world efficiency for each model.
    • Calculation: (CO2 per kWh) × (kWh per 100 km) = kg CO2 per 100 km.

    Key Takeaways

    • EU and US: Lower emissions due to cleaner electricity grids.
    • China and India: Higher emissions due to coal-heavy grids.
    • Efficiency matters: More efficient cars (like the Tesla Model 3) emit less CO2 per km, even in high-emission regions.

    User: data from polestar and rivian lifecycle analyses in 2021 estimates that over its lifetime, the electricity used by an “average” electric vecicle produces a total of 26 tonnes CO2eq. using the data we now have, can we estimate lower and upper bounds for the age of the mentioned models where they would have “produced” 26tCO2eq in different regions?

    Mistral: Let’s use the kWh per charge and CO2 per kWh by region from our earlier tables to estimate how many years it would take for the mentioned EV models to reach 26 tonnes CO2eq from charging alone, based on typical charging habits.

    Recap of Key Data

    • kWh per charge (typical): 20–40 kWh
    • CO2 per kWh (2021):
      • EU: 250 g
      • US: 380 g
      • China: 550 g
      • India: 700 g
    • Charging frequency: 2–3 times per week (104–156 charges/year)

    Calculations

    1. CO2 per Charge (kg)

    • EU: 20–40 kWh × 0.25 kg = 5–10 kg CO2/charge
    • US: 20–40 kWh × 0.38 kg = 7.6–15.2 kg CO2/charge
    • China: 20–40 kWh × 0.55 kg = 11–22 kg CO2/charge
    • India: 20–40 kWh × 0.70 kg = 14–28 kg CO2/charge

    2. Annual CO2 from Charging

    • EU: 5–10 kg/charge × 104–156 charges = 520–1,560 kg CO2/year
    • US: 7.6–15.2 kg/charge × 104–156 charges = 790–2,371 kg CO2/year
    • China: 11–22 kg/charge × 104–156 charges = 1,144–3,432 kg CO2/year
    • India: 14–28 kg/charge × 104–156 charges = 1,456–4,368 kg CO2/year

    3. Years to Reach 26 Tonnes (26,000 kg) CO2eq

    • EU: 26,000 ÷ (520–1,560) = 17–50 years
    • US: 26,000 ÷ (790–2,371) = 11–33 years
    • China: 26,000 ÷ (1,144–3,432) = 8–23 years
    • India: 26,000 ÷ (1,456–4,368) = 6–18 years

    Note: These are rough estimates based on charging habits and grid emissions, and do not include manufacturing or other lifecycle emissions.

    User: let’s see how they change with different charging frequencies.

    Mistral: Here’s how the years to reach 26 tonnes CO2eq change with different charging frequencies (1x, 2x, 3x, and 4x per week), using the same kWh per charge (20–40 kWh) and 2021 grid emissions:

    Assumptions

    • kWh per charge: 20–40 kWh
    • CO2 per kWh (2021): EU 250g, US 380g, China 550g, India 700g

    Years to 26 Tonnes CO2eq by Charging Frequency

    Region 1x/week ( 52 charges/yr) 2x/week (104 charges/yr) 3x/week (156 charges/yr) 4x/week (208 charges/yr)
    EU 34–100 years 17–50 years 11–33 years 8–25 years
    US 22–66 years 11–33 years 7–22 years 5–17 years
    China 15–45 years 8–23 years 5–15 years 4–11 years
    India 12–36 years 6–18 years 4–12 years 3–9 years

    User: what’s the average scrapping age of vehicles in the listed regions?

    Mistral: Here’s the average scrapping age of vehicles in the regions you asked about, based on the latest available data:

    Average Scrapping Age by Region (2021–2024)

    Region Average Scrapping Age Notes
    European Union ~12–17 years EU average is 12.3 years; some countries (e.g., Greece, Estonia) average 17 years. Newer cars are found in Luxembourg (~7.9 years).
    United States ~12.6 years As of 2024, the average age of cars and light trucks on the road is 12.6 years, with scrappage rates around 4.5–4.6% per year.
    China ~10–15 years Most passenger vehicles are scrapped after 10–15 years, though policies are pushing for earlier scrappage of older, more polluting vehicles.
    India ~15 years The national scrappage policy targets vehicles older than 15 years for mandatory scrapping, with incentives for voluntary scrappage of private cars over 15 years.

    my takeaway is that, if charged three times a week, which seems to be common, most ev’s get to 26tCO2eq before being scrapped no matter their location.

    • Log in | Sign up@lemmy.world
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      1 day ago

      The graph fails the plausibility check of “does using fossil fuelled car pollute about the same as EVs” and the graph trying to make out that they do. I too can ask AI questions, but I think AIs are full of shit. Here it is anyway, and the fossil fuel cars are getting a free pass for ALL the CO2 emissions during generation, which as per my other comment, are about 50 times higher assuming that oil extraction and refinery isn’t actually better than natural gas:

      CO2 Emissions Comparison

      Assumptions

      Electric Vehicle (EV):

      • Average energy consumption: 20 kWh/100 km (or 0.2 kWh/km).
      • Carbon intensity during overnight charging: 75 gCO2/kWh. Petrol Engine:
      • Average emissions: 150 gCO2/km (this can vary based on vehicle efficiency). Diesel Engine:
      • Average emissions: 120 gCO2/km (again, this can vary based on vehicle efficiency).

      CO2 Emissions Calculation

      Electric Vehicle (EV)
      Energy consumption per mile:

      • 1 km = 0.621371 miles, so 20 kWh/100 km = 20 kWh/62.1371 miles = 0.321 kWh/mile. CO2 emissions per mile:
      • 0.321 kWh/mile×75 gCO2/kWh=24.1 gCO2/mile.

      Petrol Engine
      CO2 emissions per mile:

      • 150 gCO2/km×0.621371 miles/km=93.2 gCO2/mile.

      Diesel Engine
      CO2 emissions per mile:

      • 120 gCO2/km×0.621371 miles/km=74.6 gCO2/mile.

      Summary of CO2 Emissions per Mile Vehicle Type CO2 Emissions (gCO2/mile) Electric Vehicle (EV) 24.1 Petrol Engine 93.2 Diesel Engine 74.6

      Conclusion Charging an electric vehicle overnight on a greener grid results in approximately 24.1 gCO2 per mile, which is significantly lower than the emissions from petrol engines at 93.2 gCO2 per mile and diesel engines at 74.6 gCO2 per mile. This comparison highlights the environmental advantages of EVs, especially when charged during times of high renewable energy availability. If you have any further questions or need more details, feel free to ask!

      • lime!@feddit.nu
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        1 day ago

        i’ve provided mistral with sources and asked it to summarize them, then do averages on those summarisations. i’ve not just asked it to pull data from wherever (except the scrapping thing). i too think ai’s are full of shit, but i can go back and check because i provided the data.

        the assumptions made in your text give a gCO2/kWh figure of about half the IEA’s, where’s that from? also, the emissions numbers of your fossil fuels engines are way off. assuming a fuel consumption of 10l/100km, the number for a petrol car would be 230g CO2/km rather than 150. also you’re mixing your units a lot.

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          20 hours ago

          Yeah, like I say, AI is shit. Quoting it as an authoritative source is crazy, and AI is surprisingly bad at arithmetic.

          The graphic is screwy. It doesn’t pass plausibility test. Somehow the carbon cost of generating green electricity is far higher than the carbon cost of extracting oil and refining it. Someone’s adding in a whole bunch of CO2 for manufacturing and installing some wind turbines but not for oil extraction machinery and oil refineries. Just the sheer quantity of steel alone isn’t even comparable.

          So no, you can chatgpt your argument as much as you like but you can’t convince me that the cheapest greenest wind overnight electricity I power my EV with somehow took more CO2 by quite a margin than the oil extraction, oil tankers and oil refining that my neighbour’s diesel car does. That’s so backwards and obviously incorrect and I don’t know why you persist with entertaining the idea.