I’ve just been checking up on progress on supercapacitors to see if they are up to the job of replacing car batteries yet. It looks like they will be soon. Supercapacitors have lower energy density than lithium batteries, but can be charged extremely quickly.
My favoured technique is to build mats into the road surface every 50 metres (i.e. same as streetlights), and to charge the supercapacitor bank using induction as the car passes over them. That means that even a small energy capacity would be adequate. It wouldn’t have to power the car for 100 miles or more like a battery, but only for the first and last few kilometres of a journey where there are no mats. Otherwise, range wouldn’t be limited as it would charge all the time on the trip.
However, a few minutes ago I had another little spark of enlightenment. Why not also use the pads for propulsion too, using a linear induction motor? (I like those)
If the pad gives an impulse to the car as well as a capacitor recharge, then the capacitor won’t need to be as big. And if the impulse is gentle enough, passengers won’t feel a jolt every time they drive over one.
Another little insight, hardly worthy of the name, is that with trains of self driving pods, the pods could be so close together on most journeys that they effectively have a continuous circuit from one end of the train to the other. That means that public transport pods that are only used locally and on certain routes might be able to get by with tiny capacitor banks.