Technical Look at Electric Aircraft

A somewhat technical outline view of the challenges involved:

Why don't we have electric aircraft?     by Dries Verstraete, The Conversation in TechXplore

Electric cars, trains, trams and boats already exist. That logically leads to the question: why are we not seeing large electric aircraft? And will we see them any time soon?

Why do we have electric cars and trains, but few electric planes? The main reason is that it's much simpler to radically modify a car or train, even if they look very similar to traditional fossil-fuel vehicles on the outside.

Land vehicles can easily cope with the extra mass from electricity storage or electrical propulsion systems, but aircraft are much more sensitive.

For instance, increasing the mass of a car by 35% leads to an increase in energy use of 13-20%. But for a plane, energy use is directly proportional to mass: increasing its mass by 35% means it needs 35% more energy (all other things being equal).

But that is only part of the story. Aircraft also travel much further than ground vehicles, which means a flight requires far more energy than an average road trip. Aircraft must store onboard all the energy needed to move its mass for each flight (unlike a train connected to an electrical grid). Using a heavy energy source thus means more energy is needed for a flight, which leads to extra mass, and so on and on.

For an aircraft, mass is crucial, which is why airlines fastidiously weigh luggage. Electric planes need batteries with enough energy per kilogram of battery, or the mass penalty means they simply can't fly long distances.  ... "