You must be new to the internet. These numbers are very wishful thinking for some undetermined future date.

That would have to be a pretty long cable, high voltage (to keep it light) and you'd have to stay connected roughly until you reach cruising speed for maximum effect.

Recovering the cable would also be fun (assuming it stays on the ground to save weight).

Maybe they can partner with uBeam for wireless energy transmission and screw two sets of investors in one go.