cross-posted from: https://lemmy.world/post/22892955

The Prius Prime is a dual fuel vehicle, able to run 100% on Electric, or 100% on gasoline, or a computerized blend in-between. This presents me a great opportunity to be able to do a direct comparison with the same car of an EV engine vs an ICE engine.

  • Toyota computer claims 3.2mi-per-kwhr.

  • Kill-a-watt (https://en.wikipedia.org/wiki/Kill_A_Watt) claims 2.2mi-per-kwhr.

  • Additional 1.5% losses should be assumed in the wires if you wish. (120V drops down to 118V during charging, meaning 2V of the energy was lost due to the resistance of my home’s wires).

  • Level 1 charger at home (known to be less efficient).

  • Toyota computer claims 53miles-per-gallon (American Gallon).

  • I have not independently verified the gallon usage of my car.

  • 295 miles driven total, sometimes EV, sometimes Gasoline, sometimes both.

  • 30F to 40F (-1C to 4.5C) in my area this past week.

  • Winter-blend fuel.

  • 12.5miles per $electricity-dollar (17.1c / kw-hr home charging costs)

  • 17.1 miles per $gasoline-dollar ($3.10 per gallon last fillup).

If anyone has questions about my tests. The main takeaway is that L1 charging is so low in efficiency that gasoline in my area is cheaper than electricity. Obviously the price of gasoline and electricity varies significantly area-to-area, so feel free to use my numbers to calculate / simulate the costs in your area.

There is also substantial losses of efficiency due to cold weather, that is well acknowledged by the EV community. The Prius Prime (and most other EVs) will turn on a heater to keep the battery conditioned in the winter, spending precious electricity on battery-conditioning rather than miles. Gasoline engines do not have this problem and remain as efficient in the winter.

I originally wrote this post for /c/cars, but I feel like EVs come up often enough here on /c/technology that maybe you all would be interested in my tests as well.

  • wewbullEnglish
    41·
    4 days ago
    • 12.5miles per $electricity-dollar (17.1c / kw-hr home charging costs)
    • 17.1 miles per $gasoline-dollar ($3.10 per gallon last fillup).

    UK figures:

    • Right now my electricity price is 6p/kWh, but the wind is rather high today (Storm Darragh). Still there are tariffs that guarantee 7.5p (9¢) overnight for car charging. That gives 24.3 miles per $electricity.
    • Petrol is ~£1.40 a litre here ($5.30 per US gallon). So, 9.8 miles per $gasoline.
    • LordWarfireEnglish
      4·
      4 days ago

      How is that rate possible? My UK (Octopus) electricity rate is 23.44p/kWh. The energy price cap is 24.5p/kWh. There cannot be anyone out there offering a price of 6p/kWh - I suspect you are looking at your gas price (where 6p/kWh would be about right)

      • wewbullEnglish
        51·
        4 days ago

        No. Electric. My price changes every 30 minutes.

        I wrote that message this morning when the price was low. Now at 5pm the price is nearer 40p. Obviously you don’t charge a car at peak prices.

        Over the last 4 weeks I’ve averaged 18p/kWh. That’s mainly by making sure I do things like charge the car when it’s cheap.

        My rate is very variable, but the figure I used is the off-peak rate on a rate designed for EV owners that gives cheap overnight electricity.

        My gas price is 5.9p/kWh which also changes, but day by day. Today is average.

        • dragontamer@lemmy.worldOPEnglish
          3·
          4 days ago

          I did read about wind energy making night time costs very low for some areas of the UK. Thanks for the graph, it helps me understand it.

          In my state in the USA, I have a choice between one price at all times (17c, all taxes and surcharges included) or a on-peak/off-peak pricing structure of 28c on-peak and 12c off-peak.

          Not as extreme as your every 30 minutes of change but if I squint I can kinda-sorta see my price differences kinda lining up with yours.

          My lows aren’t as low and the highs aren’t as high. They are also multiple hours long of on peak vs off peak.

    • dragontamer@lemmy.worldOPEnglish
      3·
      4 days ago

      Interesting. The internet suggests 22p/kwhr is the UK average ($0.27/kwhr in US dollar)

      I do have a time of use program that I could take advantage of to drop my night time / off peak prices. But my on-peak prices go up so much that even with the EV I’m not saving any money.

      I’m only going to drop from like 17c to 12c if I switch to the EV time of use program, or a change of like $1.70/night worth of charging to $1.20/night (10kwhr per typical day of travel)

      Do UK citizens pay generation + transmission + taxes like we do in the USA?

      8p/kwhr (10c/kwhr) is very close to the time of use / night time charge generation costs of my area. However, there are still local tax, surcharges, and transmission I have to pay for that would take that up to 17c when it’s all accounted for.

      • wewbullEnglish
        21·
        4 days ago

        Do UK citizens pay generation + transmission + taxes like we do in the USA?

        We pay a standing charge per day. Mine is 40p. So every day my costs are 40p + my per kWh costs. There’s also 5% tax on domestic electricity, but the prices I quoted include this.