Solar is now not only the cheapest energy it's cheaper to intitially deploy than non-renewables.
Doesn't mean we should waste energy; it does mean that we have crossed a threshold beyond which energy concerns change shape.
"Honey, why is there a solar panel-maximizer converting our car?"
Sunlight no longer reaches the earth's surface but at least we know P vs NP
You just need to work your way down to a deeper layer in the https://en.wikipedia.org/wiki/Matrioshka_brain Not the deepest layer. Humans would fry instantly there. But, the warm glow of the third layer down upon the fourth is quite pleasant.