[jillesvangurp]

You're taking current batteries as the benchmark and comparing them to a 747. A 747 takes about 50K gallons of kerosene. Or roughly 150 tonnes; according to wikipedia the maximum takeoff weight for a 747 is around 500 tonnes. That's also a good explanation of why these big planes are being replaced by smaller ones; using that much fuel is stupendously expensive.

The reason why the engines and fuel are in the wings has more to do with the center of gravity. This needs to be where the wings are for the plane to be stable because of the non trivial amounts of fuel that get burned and the weight of the engines. If you'd store this in the back or front of the plane, the plane would get progressively harder to control through the flight.

With batteries, this is a non issue. You can put them wherever as long as the center of gravity is in the right place. It won't shift as you deplete the batteries. But still, the wings are probably going to be a popular place for this.

Comparing with a long haul 747 is of course a bit unfair. It is worth noting that these planes are being replaced by more efficient two engine planes that are lighter and much more efficient. But I agree it will be a while before we see cross Atlantic flights at that scale. But we're talking short haul here; 1-2 hour flights.

[aerodude]

I didn't just compare with a 747 -- the battery numbers I ran were for the business jet. The 747 obviously looks far worse. If you want mass for a 2 hour journey in an electric business jet, divide those numbers by 5. Also the battery numbers I ran were for the upper range of current lithium-ion tech. If there are batteries on the market that have an energy density of 265Wh/kg, I haven't seen them. I'm no battery expert so I could be wrong, but from what I understand, most current batteries sit at around 60-70% of that.

A non-shifting static margin is certainly a benefit for electric aircraft, but we already successfully design aircraft that do have a shifting static margin. The interesting question is whether or not a constant mass would let you design airframes that would be impossible with fuel and ICE.

1-2 hours looks possible using current and near-future technology, but has anyone actually done a cost analysis on flying electric aircraft that are always at "full fuel" weight versus standard aircraft doing the same journey with half a tank? I can't imagine it's completely cut and dry, because the aerospace industry has had its eye on various forms of electric propulsion for decades.

Also, what's the turnaround on these things? Airlines want to make money, so they want to minimize the amount of time the aircraft spends on the ground. That's going to be a major hurdle, since even charging 2MWh over the course of an hour or so requires 2MW of power going into the vehicle. That's not an ungodly amount, but it's still non-trivial.

[Kimm0n0]

Most domestic flights in Norway last less than an hour, like Bergen - Oslo and Stavanger to Oslo.