I know there are plenty of engineering/techie types here, and I wondered what all y'all thought. I know that some of you will see the latest Gee-Whiz electric aircraft at Oshkosh. That got me thinking. Most objections to electric aircraft in particular involve the batteries. They're too heavy, they're expensive, they don't have enough range. But assume that someone works a miracle and develops a battery that can store gobs and gobs of juice, that will be lightweight, and (biggest miracle of all), reasonably-priced. The way I see it, there's still a BIG problem: physics ... as in, you can't cheat 'im. You have to fill the batteries with energy before you can pull watt #1 from it. Just to have some numbers to play with, ignoring losses and just doing some back-of-napkin math: 100 HP is 75KW. If you want to fly for 5 hours, you will need 375 kilowatt hours (5 x 75) of juice put in the batteries. (That's a bare minimum; ignoring losses and assuming that a boost circuit could play "joule thief" and drag every available drop from the batteries later.) Tesla has some numbers for their cars that illustrate the problem. Charging at 240 V, the draw (depending on model) ranges from 30 to 40 amperes. Charge time is several hours. Now: consider the average FBO. If he/she only has to charge one plane every now and then, meh, maybe it's not a big deal. But if there are several planes on the ramp, each needing a 240V, 40A service to charge in any rational amount of time, that's going to require some very expensive electrical work (and probably a major upgrade to the utility service). Tesla owners could pipe in here, too. Remember, I'm talking about the real world, where more than one person might want to fly this New Miracle Airplane(tm). In the real world, there are going to be lots of people who want to draw that 240V/40A for hours on end to top off their batteries.