4 ms·
It maybe isn't quite as bad as you think, as what really matters is the thrust for the combined weight of the engine and power source rather than just the energ
by elektromekatron 11y ago
It maybe isn't quite as bad as you think, as what really matters is the thrust for the combined weight of the engine and power source rather than just the energy density of the power source in joules per kilo. Combustion is generally pretty lousy, compared to electric, at converting joules into useful newtons.
- masklinn 11y agoCombustion is about 30% efficient, electric is about 95% efficient, so for the same energy input electric gets you 3 times (and a bit) the output. Problem is, getting the same energy input via batteries weights 50~100 times as much as fuel does, and takes 15~40 times as much room. So your fuel still weighs 20~30 times as much, and takes 5~10 times as much room in your plane. And while combustion is 30% efficient part of the energy loss can be used to heat up the cabin, because at 30000~40000ft you're not exactly at sauna temperatures outside, so now you need to spend part of your electricity to heat passengers and your batteries (because most of them don't like operating at 200K)