Does the aircraft use jet engines? How is the 'excess' power transferred to the generator? Can you generate a decent, usable amount of a power from such a short section of the flight, and does it offset the extra power needed for the weight from the (presumably) heavy batteries? I have a very good friend who produces batteries for electric cars, trains and bikes... I could put you in touch, but I'm not 100% sure about the efficiencies of such a system..?