Comment by ben_w

The blog is suggesting 10 GW, which is well short of "the entire thing", and they also suggest a lot of redundancy.

If you were to use a single cable for everything, that would be silly because no redundancy, e.g. "A volcano? On the mid-Atlantic ridge? Who could have foreseen this?"

But at the same time, a cable big enough to carry the world's power is pretty big. I've done similar ballpark calculations, and to get the electrical resistance all the way around the planet and back down to 1Ω, you'd need almost exactly one square meter cross section of aluminium (so any anchor cable breaks first), and that would have so much current flowing through it that spinning metal cutting tools can't operate nearby thanks to eddy currents from the magnetic field.