Anons argue in comments

  • TDCN@feddit.dk
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    8 days ago

    Nice graphic. But it seems like it doesn’t factor in kg of mass moved. A human and a bike is a lot lighter than a car or a horse. You could also argue that the vehicle weigh should be ignored but then again you could easily argue back that weight of goods move can possibly be a lot higher with a car if you load it up to capacity. Ignore that. I did not see it said 5 riders for the car

    • SoleInvictus@lemmy.blahaj.zone
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      7 days ago

      I’m back with better data. I’m assuming the travel path is perfectly flat because I don’t feel like modeling elevation changes. I’m being energy efficient (read: lazy).

      For cycling, I’m using the global average human weight of 62 kg, assuming the cycle is 8 kg, and the pace is 10 kph, which is pretty relaxed.

      For walking, I’m using the 62 kg person walking at 4 kph.

      For driving with petrol, we’ll use the same spherical 62 kg human and a 2024 Toyota Prius with a fuel efficiency of 4.8 L/100 km and a mass of 1570 kg. One liter of petrol is approximately 8174 kcal. Double the energy expenditure for an estimate for your typical SUV.

      For electric, I chose a 2024 Hyundai Ioniq 5 N with an energy efficiency of 21.2 kWh/100km and a mass of 2235 kg. One kilowatt-hour is approximately 860 kcal.

      Walking: 0.74 kcal•km-1•kg-1
      Cycling: 0.34 kcal•km-1•kg-1
      Driving(p): 0.24 kcal•km-1•kg-1
      Driving(e): 0.08 kcal•km-1•kg-1

      Edit: keep in mind this includes the energy required for each vehicle to move its own mass. If we calculate the energy required just to move a single person and NOT the vehicle, we get:

      Walking: 0.74 kcal•km-1•kg-1
      Cycling: 0.38 kcal•km-1•kg-1
      Driving(p): 6.32 kcal•km-1•kg-1
      Driving(e): 2.96 kcal•km-1•kg-1

      Only in an electric car jammed with 5 people (0.59 kcal•km-1•kg-1) do we begin to get close to walking efficiency again.

      @TDCN@feddit.dk: this update might be closer to what you’re looking for.

      • TDCN@feddit.dk
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        7 days ago

        If only I could up vote your comment again. These numbers are really nice to have.

      • TDCN@feddit.dk
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        8 days ago

        Oh really. It seems to contradict the graphics. Cars are also stupid efficient now. I also ran some quick calculations on my electric bike and it is crazy how many km*kWh⁻¹ you get and how little it cost to run.

        I’ve heard about some research showing that an electric bike over it’s entire lifetime is more environmentally friendly than a traditional one because the amount of extra food you need to consume without the electric help is over time more co2 than the co2 it costs to charge the battery. I don’t know where the research is from since I just heard it from a colleague so don’t quote me on it, but electric motors are really efficient so it sounds very plausible to me.

        • SoleInvictus@lemmy.blahaj.zone
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          8 days ago

          Electric bikes are super efficient, I’m a big fan.

          While the petrol and electric vehicles are surprisingly efficient moving a given unit of weight, that also includes their own weight, constantly, making their overall energy use…not great.

        • SoleInvictus@lemmy.blahaj.zone
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          8 days ago

          Yes and no. They take less energy to move a given unit of weight around, but they’re massively heavy so they expend tons of energy moving themselves the entire time.

        • endeavor@sopuli.xyz
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          8 days ago

          Seems so. Even cheating it in favor of the bikes. But looking at electric car numbers it should make ebikes even more effecient.

    • SoleInvictus@lemmy.blahaj.zone
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      8 days ago

      It still doesn’t give us kcal•km-1•kg-1 (or an equivalent), which is what I was looking for. We could do some math to get us some loose estimates, though. I’ll do exactly that and report back shortly.