Simple. There is no national grid that can nor will supply the energy needed to replace the energy currently supplied by hydrocarbons. Not daily, not hourly.
I’ll keep it extremely simple to be comprehensible. To transport the equivalent of hydrocarbon energy content to electricity you need very high capacity 24/7 power plants. You need to have high capacity transport lines in the 1000 kV range which need multiple transformers to step down the energy to the level it won’t blow up your car.
You need the cables, either from aluminum or copper to take up the charge. No national grid has this. So you need to replace the whole infrastructure down to the connection of your domicile to the grid.
The grid needs to be able to compensate for the wildly varying supply now that so called green power plants come on line. Solar doesn’t work at night, wind farms don’t work when there is either to much or to little wind.
But even if they would work 24/7 (current levels are at best 20% of rated capacity in the northern hemisphere) still no city has the infrastructure to cope with a projected demand of 100% EV vehicles, ships, airplanes.
In fact even the very big conglomerates with the most modern infrastructure won’t be able to supply all energy needs including vehicles without melting the transport lines.
On purpose i refrained from introducing the calculations of how much energy is generated using hydrocarbons and how there is noway anyone will be able to replace it by green energy nor realistically transmit it to the end-user.
The problem here is that those who profess this replacement live in large cities, with relatively few EV vehicles and electricity supplied by fossil fuels without realizing that the the rest of the world doesn’t have an infrastructure even capable to keep a refrigerator running without fail let alone charge an EV vehicle.
And don’t get me started on long haul trucks. Only a very small part of the world has flat straight roads with high capacity power lines.
Or transatlantic freight-ships. Where are you going to charge your 200.000 tonnes capacity container-ship? The Panama canal?