Actually the case for electric is quite strong at the light ASEL end of the spectrum. At this point fully practical I think to do 1-2 hour local training flights with an all electric plane.

They do as you said have to tighten up on the fire safety and certification of batteries. But that's really a matter of doing it... don't need new tech, just need very rigorous production tolerances and QA in battery manufacture. Batteries really only fail catastrophically if they are made sloppily (or damaged but hopefully they would be packaged/mounted so as to preclude that in an aircraft).

But if they take shortcuts on battery safety in their rush to market it will blow up in their faces (pun intended).


The battery case gets weaker as you get bigger, maxing out around ten pax and 500-800 NM range. After that you need hybrid which has an additional technical challenge: weight of all the extra gear cancels out the benefit. I expect they can make enough progress on the system weight issue to make hybrid practical in the short (maybe medium) haul RJ market.

After that, it gets harder to make the case for even hybrid although you could probably get benefit from having say two electric motor-powered fans driven by two jumbo APUs (engines really) internal to the fuselage. Use both APU's for critical phases and climb, but shut one down in cruise to save gas and wear and tear. The cruise APU would be optimized to run at one speed and power setting in cruise and would be very efficient. But no real case for batteries in long haul ops so you'd have to burn liquid fuel for all your energy needs, not practical to try to bring grid power with you.

Compared to liquid fuel batteries have another big drawback that nobody ever thinks of... they don't get lighter over the course of a long flight.