[aphextron]

>"Anyone know how far we are from electric jets? Is such a thing even possible?"

Electric will never replace long haul jets barring a revolutionary breakthrough in battery technology. But that's not the point. Much of commercial aviation takes place on distances of around 100 to 500 miles. That is, too far to drive but not quite far enough to take advantage of the efficiency of jet engines at high speed, high altitude cruise. For those applications electric propellor and ducted fan aircraft will be absolutely game changing. It will make these flights cheaper and safer by a factor of 10 at least. The vast majority of cost in a flight is maintenance of the engine. That all goes away with electric power. It will make commuter flights an affordable daily reality for normal people.

[boatswain]

Would a hybrid model be more effective? Using diesel generators to power electric motors?

[Gibbon1]

Hybrids are interesting because you can reach higher bypass ratio's because you can power n number of ducted fans off m engines.

Currently increasing fan sizes are getting problematic. That is the problem with the 737 MAX. The fan diameter of the new engines is too large to fit between the bottom of the wing and the ground. So it had to be mounted forward and up which fucked up the aerodynamics.

Two other advantages are, potentially maintaining thrust in an engine out situation. When you lose an engine not only do you lose half your power but the thrust is unbalanced. And faster throttle response. Turbine lag is a big issue with jetliners.

Note: The reasoning behind high bypass turbofans is thrust is proportional to delta v times the mass flow rate. Where power input is proportional to delta v squared. Bigger the fan the more efficient you are and the less fuel you use.

Diesel is kinda interesting. Manufactures are developing diesel engines for light aviation. I suppose you could have a hybrid diesel/electric aircraft.