And if you just look at the state of battery tech, that does not actually look unreasonable to provide. There are commercially available high-energy cells that

And if you just look at the state of battery tech, that does not actually look unreasonable to provide. There are commercially available high-energy cells that provide ~900W/kg. That's ~22t for the cells, round up to 30t for the other stuff. Coincidentally, that's roughly similar to the fuel capacity of an A320, to which they compared their engine power. You could push the specific power up quite a lot, but you'd have to start sacrificing specific energy, which is the sticking point of electric airplanes. With those batteries, you only get 5MWh, or you could only provide that 20MW for ~15 minutes. This is not as bad as it sounds, because airplanes only need to provide near their maximum power for relatively briefly. There are many short hop routes where that airplane can operate profitably. Still, it should make clear the point that the deficiency of electric airplanes is not their power, but their range. When you fit a plane with batteries that contain sufficient energy to go anywhere useful, you also provide it with frankly excessive power to run it's engines.