Re:Electric Planes Usher in the Second Great Age of Aviation
by masklinn on Tuesday July 28, 2015 @03:14PM
(#9963851)
Combustion 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)
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)