Kerosene also benefits from the fact that it is consumed over the course of the flight, so that an airplane gets lighter and therefore less fuel-intensive as it

Kerosene also benefits from the fact that it is consumed over the course of the flight, so that an airplane gets lighter and therefore less fuel-intensive as it flies. The weight of enough batteries for a fully electric narrow-body airliner is punishing when you consider that you have to carry that weight around all the time instead of it steadily decreasing from takeoff onward. I haven't run the numbers, but off the cuff I'd estimate that you need at least one more doubling of energy density to account for the higher average weight of the aircraft in flight. Now you have to hope you can maintain sustained consistent improvements for half a century just to get into the realm where battery energy densities start to make sense for a fully electric airliner with the same capabilities as our fully hydrocarbon based airliners of today. And of course it's not anywhere near as simple as swapping the engines on existing air frames, so if you want to have your electric airplane the day that the batteries exist, you need to make a pretty sizeable bet today by investing in the groundwork for all of the other systems.