Originally Posted by
Bergerie1
A great start for electric power, but surely simple physics limits what can be achieved unless someone invents an entirely new kind of battery.
For example, the specific energy of avgas and jet fuel is about 43 MJ/kg. The best lithium-ion batteries top out at about 0.9 MJ/kg (the batteries in a Tesla are about 0.7 MJ/kg), so they have a fraction of the storage of liquid fuels. The best battery technology in theoretical development (Lithium-air) has a theoretical maximum of 41 MJ/kg, more realistically they'll get 1/4 to 1/3 of that from the technology.
Don't forget that electric motors are typically 90 to 98% efficient, whereas a petrol powered piston engine is likely to be around 30 to 40% efficient. Thus your 43MJ/kg avgas is closer to 15MJ/kg. There's still a long way to go, but it does rather narrow the gap.