Except for specific niches, it's mostly useless as a large-scale power source, for the simple reason that the sun - from the Earth's perspective - is an inconstant energy source that doesn't put out enough.
A 40-acre solar farm was just put in near where I live. My first response was, "Hmm, I wonder who's going to keep all those solar panels clean?"
Undocumented workers.
“is an inconstant energy source that doesn’t put out enough.”
Sounds like my Ex!