Yeah, so, the first thing to know about that is ICE is ludicrously inefficient. Spinning all that metal at variable speed with tiny explosions is, unsurprisingly, not the best way to turn high density fuels into energy. The thing ICE had on its side is the energy density, on other metrics it's a bad deal (hence why free charging for EVs is affordable)
So if you have 400MW of ICE cars you don't need 400MW of electricity to replace that, something more like 80-100MW is more like it IIRC. The infrastructure build cost isn't zero, but it's much less than this 150% metric suggests.
No, they're not. They're, as implemented in a car, a ludicrous example of engineering compromises.
Put a hybrid drive methane spark-ignition high compression engine and you'll have similar CO2 emissions from a e-car powered by a thermal plant (the vast majority of our power). It'll cost as much as a Tesla too.
Getting some rough numbers from Wikipedia it looks like most common new cars are sitting around 35% thermal efficiency. I believe a formula 1 engine achieved 50% thermal efficiency recently but the cost of that is obscenely high. Where as electric motor efficiency easily hits 90%+.
It's also quite inefficient to convert hydrocarbon energy to mechanical energy to electrical energy to chemical energy back to electrical energy and then back to mechanical energy, as an electric car does. ICE goes straight from hydrocarbon to mechanical. It would not surprise me if it's more efficient, though I don't know.
So if you have 400MW of ICE cars you don't need 400MW of electricity to replace that, something more like 80-100MW is more like it IIRC. The infrastructure build cost isn't zero, but it's much less than this 150% metric suggests.