"But if all cars convert to electric in 20 years then will have...

"But if all cars convert to electric in 20 years then will have to massively increase the grid power supply (double, treble, ...) to 'fuel' them?"

Or trickle charge "fuel" cars at night when the demand for electricity is low
Agree with the Author though Musk's battery for SA is a gold plated band aid paid by the tax payer , given the Adelaide hills are so close and the Flinders ranges pumped hydro would offer far more capacity and cheaper , God has already made the battery ie the hills , just need to charge them with water .