So I’ve heard this lots of places but never done the math, so I sat down this afternoon to try and work it out and…it’s super complicated. The generator in the picture might not charge the car at all…if it is, it’s probably a trickle charge like plugging into a 120v outlet…which means running the generator for a very long time for a very small charge which means it’s super inefficient…depending on your starting assumptions you get anywhere from 11 - 20 miles of charge out of a gallon of fuel for the generator, which is less efficient than tha average of 31 mpg for a 2022 sedan…so in that case, it’s less efficient. The more normal use case would be a whole-home generator powering a level 2 or 3 charger in your garage… which can be more efficient than an ICE engine assuming a high-efficiency generator and EV. Additionally, generators don’t typically have emissions controls, so from a carbon standpoint, it’s WAY worse than an ICE with a catalytic converter.
So I’ve heard this lots of places but never done the math, so I sat down this afternoon to try and work it out and…it’s super complicated. The generator in the picture might not charge the car at all…if it is, it’s probably a trickle charge like plugging into a 120v outlet…which means running the generator for a very long time for a very small charge which means it’s super inefficient…depending on your starting assumptions you get anywhere from 11 - 20 miles of charge out of a gallon of fuel for the generator, which is less efficient than tha average of 31 mpg for a 2022 sedan…so in that case, it’s less efficient. The more normal use case would be a whole-home generator powering a level 2 or 3 charger in your garage… which can be more efficient than an ICE engine assuming a high-efficiency generator and EV. Additionally, generators don’t typically have emissions controls, so from a carbon standpoint, it’s WAY worse than an ICE with a catalytic converter.