wrote:
It's probably some kind of ultra high voltage DC pancake motor that
would require it's own special APU to power it. It would have to
develope on the order of three to four hundred horsepower to be able to
reliably move a fully loaded jet around under all the taxi conditions
that a jet might see. In addition it would either have to be able to
spool up at a fast enough rate as to not rip the nose gear tires off
the rims on landing or be disconnected from the nose wheels on landing.

I was pondering a similar question earlier this week as I watched
gasoline prices increase.
The conversion from horsepower to kilowatts is 1:0.75, so a 400 hp
engine is 300 kw.
I was curious as to how large a 300 kw motor is and how massive the
power cables are to provide the requisite voltage and current.
1000 V and 300 A?
How much energy is lost to heating?
How does one reduce this heating loss?
How many kw does it take to start a given mass moving?
I am guessing there is an initial surge current, followed by reduction
in current once the mass is in motion and to keep it moving.