• sexual_tomato@lemmy.dbzer0.com
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    5 months ago

    What’s the efficiency for turning jet fuel into mechanical work? I’d suspect the efficiency is somewhere around 45% for liquid fuel where it’s nearly 100% for electric. So you’re really trying to reach the equivalent of 5500 Wh/kg.

    • Skull giver@popplesburger.hilciferous.nl
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      5 months ago

      A factor in favour of jet fuel is that as the plane burns fuel if becomes lighter, thus consuming less fuel. Batteries stay the same weight. The difference between a full plane and an empty plane can be 18 metric tonnes. Super cheap operators tend to carry only a small extra margin of fuel over the amount technically necessary to make a trip, because it makes a real difference.

      That means the energy density you need in this comparison isn’t really linear. If you’re doing Taylor Swift flights to the couch and back, you can save a lot of weight by having a minimal amount of fuel in the tank, but with an electric plane you’ll always have to have the full battery in case you need to go somewhere further away.