There is plenty of capacity, more and more cars have bidirectional charging, so soon we will have scenarios like the USA where Tesla owners can join the Tesla power company and sell power back at peak hours (of course Elon gets a cut). So this will allow our existing power grid to operate at a high load for more hours. So lets say you charge your car to 100% at night, and in the morning peak the grid takes 20-30% back (or whatever you want to offer). That will add a VAST amount of capacity to our grid will very little investment.