This is worth considering, but FWIW, 50 GW would be around 10% of US electricity if it runs continuously (the US consumes at a rate of about 500 GW if you divide total consumption by one year). If the new capacity is as clean as the overall electric grid that would be about 2.5% of US emissions (25% of US emissions come from electricity) and 0.35% of global emissions (US emissions are 1⁄7 of global emissions).
I’m not going to do this math now but I think if the new capacity is 100% natural gas then that’s about as carbon-intense as the US electric grid as a whole, or maybe somewhat worse (the US has a lot of clean energy, but it also has coal plants which are >2x more carbon intense than gas). 100% natural gas would be the worst case, because there is no scenario where the US builds new coal plants (edit: it’s not the worst case, because increased power demand could cause the delay of coal plant retirements, but I don’t think this changes the conclusion all that much)
Kinda weird that the story contains an intelligence explosion that happens both incredibly fast and incredibly soon but glosses over how it happens in a single paragraph, in favor of descriptions of nanobots dematerializing people.