That said: I think solar is niche, and a moon-shot for how they want it. Nuclear is the future of reliable energy for human civilization.
I think the K-scale is the wrong metric. I don't think we should be trying to take all the sun's energy as a goal (don't blot out the sun! don't hide it in a bushel!), or as a civilizational utiltiy - I'm sure better power supplies will come along.
Building data centers in Antarctica with nuclear power would be easier. And still way harder than necessary.