"What? It seems preposterous that in July 2024 they’ll have double the current capacity, or will have "needed to" (what happens if they don’t?). Do you have a citation?"

There’s a german professor – Harald Lesch – who made a few science documentariers regarding the switch from fossil fuels to alternatives. I don’t have the exact link but you should be able to just google "harald lesch elektromobilität youtube". It’s in german, alas.

The logic is pretty simple however; Charging an electric car takes a lot of power. Try around 7200 watts. The average household consumes between 25-35 kWh, so it’s around 30% of that. Since you always want to build the grid with a very large proportional margin to avoid burnouts, that’s where we get a conservative estimate of having to double the capacity.
But the strain alone isn’t the whole issue. Currently all the power lines terminate at power stations which are mainly…gas plants, coal plants, nuclear plants, etc. You need to build extensive cabling, transformer stations etc to accommodate the power generation locations suddenly shifting as well.

"What do you mean by "civilian part" of the grid? Is another part equipped to handle this load?"

I’m not sure of the exact word in english…the part of the power grid which isn’t a main trunk. The network extending the last few miles to households. Powerhungry factories often need to lay extra cable just to accommodate power requirements. Intercity cabling is also prepared to bear higher loads.

Normally when you run power through a network there are limits to how much power you can run without the network overheating or overloading. If demand exceeds possible supply you get brownouts and occasionally a whole lot of very large blown fuses unless there’s a catastrophic malfunction in which case some transformer station somewhere catches fire.

" Could cars feeding power into the grid help with any of this?"

If we were thinking about hydrogen fuel cell cars then yes. Otherwise…well, you couldn’t get power out of nothing but to some extent you can mitigate the strain. If you could get every person to charge their cars in shifts so the constant burden didn’t come all at once maybe…still not ideal though.

"people generally seem to think battery-powered cars have significantly lower maintenance costs than fuel-burning cars (and much higher purchase costs)."

Sort of correct; Electrovehicles have far fewer moving parts suffering high mechanical stress than a combustion car. Less wear and tear and the parts you need to replace are rarely going to cost you the same way a transmission will, for instance. No difference in chassi maintenance of course.

However, all batteries degrade in performance, so an EV will degrade in performance quite predictably. And replacing the battery is an operation as significant and expensive as replacing a high-cost engine. You may be better off buying a new car in the end, with better specs.

And of course it’s still an open question whether the environment can even bear the current frenzied lithium extraction taking place. It honestly makes strip-mining look ecologically defensible in comparison.

"The question isn’t "will it interfere with some imaginary arcadia which never was" but "is it better than the current situation"? "

And the point is, that’s dubious. Really. Short term we’re going to have to get rid of fossil fuels. Full stop.
Long term we’re looking at an extraction type which makes fracking look pretty nice in comparison.

It’s a similar issue as the one we have with wind and water; long term they’re great at "paying" for the carbon footprint of their manufacture, but short-term manufacturing the bloody things carry a carbon footprint in itself.

If what we’re looking for is real, immediate mitigation of global warming then we’re at the point right now where we’ve dragged our feet for so long on switching that the only realistic way of putting the brakes on the earth warming up is to either switch off every industry unable to curb it’s pollution and ban every car without a carbon trap…or find a way to magically trap fairly staggering amounts of greenhouse gas in short order.

"The complaints about grid limits are laughable – we already have a solution for that it is called your electricity bill."

If that worked then you could similarly have curbed CO2 expenditure by just raising gas taxes. But we all know how that goes. The price of a utility goes over a certain point and then suddenly there’s a new politician who got elected on a platform of lowering utility pricing and the whole idea falls flat.

"They start construction in response to demand growth and issue bonds/take loans to pay for it over time."

That’s not really how it works. Construction starts when there’s a profit motive or when sufficient government money is invested. And unfortunately even in diehard "Green" countries politics take a lamentably short view of things which in some places stalls the switch completely. Bavaria in germany stands out with south germany almost not building a single watt worth of wind power in the last few years.

Which means cheap electricity in europe is more often than not obtained by energy from…coal and gas power plants from the old east bloc. In the US I probably don’t need to tell you where the profit motive is. Coal and gas are, bluntly put, cheap.

Going off fossils is an uphill struggle and the last thing we need is to sit back and say "Oh, we fixed it". We haven’t. EV’s aren’t going to make a significant impact. Not at this point in time. That window of opportunity closed twenty years ago.

If people had taken this shit seriously back in the 80’s then we’d have gotten it done. Today it’s all too little, too late.