Reliably and efficiently transport energy generated in space back to earth, for starters

Or let me guess, its going to be profitable to mine crypto in space (thereby solving the problem of transporting the "work" back to earth)

If we (as in "civilization") were able to produce that many solar panels, we should cover all the deserts with them. It will also shift the local climate balance towards a more habitable ecosystem, enabling first vegetation and then slowly growing the rest of the food chain.