• melsaskca@lemmy.ca
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    14 hours ago

    Is there no simple anymore? Plane A went this far on 5 dollars electricity. Plane B went the same distance on X dollars worth of jet fuel. I want to know the distance travelled and I want to know what “X” is.

    • betanumerus@lemmy.ca
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      11 hours ago

      $5 for 30 minutes in the air. pick any speed you want. it doesn’t matter. avgas and jet fuel don’t compete with $5.

    • xthexder@l.sw0.com
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      12 hours ago

      Well, the data we do have is that the flight was just under 30 minutes and very likely under 100 miles.

      From the Wikipedia on airline fuel efficiency:

      The worst-performing flights are short trips of from 500 to 1500 kilometers because the fuel used for takeoff is relatively large compared to the amount expended in the cruise segment, and because less fuel-efficient regional jets are typically used on shorter flights.

      In the example values table, the most efficient plane for a 560km trip burns 0.92 kg of fuel per km, so doing some rough math and assuming the electric plane travelled 100 miles, that would be roughly 148kg of fuel, or 50 gallons (190L).

      At current jet fuel prices ( $3.76/gallon ) that’s about $188 US in jet fuel as a rough estimate. It’s unclear if the test flight went up to full altitude or if the plane was at full weight, so a fair comparison might have used even half as much jet fuel.

      Edit: From some of the other comments, it seems like they might have only considered flight time as cruising time, not takeoff and landing, so my numbers will be quite far off if that’s the case. My gut feeling is that this is probably the case, because this seems like too big a difference otherwise.

      • UnderpantsWeevil@lemmy.world
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        10 hours ago

        $5 of electricity to lift an airplane 10,000 feet definitely seems low.

        If you want to be really smug, you could say a gas powered plane requires $0 of fuel to glide for 30 minutes

        • xthexder@l.sw0.com
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          1 hour ago

          Now that you mention it, they specify a maximum total weight of 25,000 lbs, so at 100% efficiency it would take 339MJ of energy to lift the fully loaded plane to 10,000 ft. That can be converted as 94 kWh, and at the current cheapest electricity price in the US of $0.1235/kWh, that’s $11.63

          Therefore, it is literally impossible for this plane to reach 10,000 ft for $5 fully loaded.

          • UnderpantsWeevil@lemmy.world
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            1 hour ago

            price in the US of $0.1235/kWh, that’s $11.63

            Way cheaper than I’d have guessed.

            737 at max takeoff weight is 175k lbs. So that’s around $80 to get airborne. Seems like a steal when you’re charging easily triple that for one seat.