Here’s a bus with something sticking into it. Yes, it’s a plug in bus. It trundles along on route 73 in Stockholm and at one terminus this device extends itself downwards like some kind of alien parasite and in six minutes supplies enough electrons to enable another round trip without resorting to the engine (it’s a hybrid).

Yes, I took a trip specially out of curiosity. It’s pleasingly smooth and quiet but for all that it’s still a bus crashing over uneven surfaces and you still have to share it with persons of sometimes doubtful hygiene.