Originally Posted by
msjh
I'm afraid neither of these arguments convinces me (yet). But I am willing to learn!
I think for the compassion to work you need to compare
- the weight of the fuel tank (and bits and pieces like fuel lines, exhaust system, etc) vs weight of the batteries
- the weight of the petrol or diesel vs the "weight" of a charged battery vs depleted battery
I appreciate that in a plane you need the engines to produce enough power to generate lift, which is not needed in a car. But I think that 400x figure is substantially too high.
Three years ago,
Forbes reported a study by scientists that Teslas (and EVs in general) produce substantially less pollution than ICE cars when all factors are taken into account.
(Incidentally, I photographed a
small electric plane at Farnborough Air Show a few years back.
These are no arguments, these are facts, painfully learnt by me at work.
There are many more figures that go into the comparison, none of them changing the result.
For example, the weight of a foam filled fuel tank is usually 10% of the capacity, so for a cessna it would be about 12kg. Which equals the battery management system (BMS), roughly, for that power.
If i take into account the average weight of the system during a trip, a x1.5 is instantly granted to the thermal fuel, which you don't need to carry when you are almost empty.
In the advanced electric propulsion world, the figure you shoud use is x100 (x400 is fuel vs standard car battery, x2 / x3 electric motor efficiency vs thermal motor, x2 LI-IOn vs standar car battery). But do remember that if you use x100 you pay over 25000$ to have a equivalent energy storage capacity of 50L of fuel (vs the fuel tank itself at about 500$)
And remember the only reason that topping a battery is cheaper than topping a fuel tank is politics. It doesn't make any sense that the elaborated product (electricity) is cheaper than the base product (gas). In 2014, 66% of world electricity was generated burning stuff. Even if it were any difference in price, it would never ever be greater than x1.5 or something.
I wish electricity was actually cheaper, don't get me wrong, I wish a solar plant or aero generator wasn't so weak in terms of power / $. I hope this changes in the future. It may change.
But electric flight? short of battery technology breakthrough, no way.