The FIA in it's abysmal wisdom would want to control exactly how much electricity each car would have. So this would be done by putting contact strips on the track surface providing current to the cars through braided metal strips running underneath. The cars would then have vertical rods descending beneath them which would run in grooves cut into the track. This would also add a much needed safety element in keeping the cars from running off the track.
Or has this been done already? Hmmmm......