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bb123today at 8:27 AM1 replyview on HN

I'm much less optimistic. Even when factoring in the poor thermal efficiency of gas turbines (~30-40%) compared to electric (>90%), the usable specific energy gap remains immense. Jet-A still delivers roughly 14 times more useful work per kilogram than modern batteries. Removing fuel plumbing and tweaking airframes won't overcome that fundamental physics. Also the issue with the high-altitude efficiency argument is that batteries, unlike liquid fuel, don't lose mass during flight meaning the aircraft to haul its maximum takeoff weight from departure to arrival. It's a double whammy.


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ericdtoday at 12:41 PM

Well, in this case, we don’t need to argue about theory. The Joby has a tested range of 150 miles. They also tested it with hydrogen fuel cells and got >500.

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