It is often surprising that most of the US is south of most of Europe (the common reference is that Chicago and Rome are both 42N. The jet stream complicates the effect on overall climate, but latitude is pretty much the only thing that matters for solar power.)
Solar panels are mildly more efficient when colder, the same latitude in an area with similar cloud cover in north America is probably generally slightly better for solar than Europe because it is colder, not sure if it would ever be more than a rounding error though.
The difference between surface solar radiation levels in the US and Europe are wild[1], fully agree on the rounding error view. Anchorage seems to receive the same level of watts per area as Germany and Poland.
Need a renewables feasibility index that accounts for the amount of solar, wind, hydro vs climate and typical weather. And bin plot population vs that.
Seems obvious that Norway, Washington State have lots of hydro. Places like Spain and California have lots of steady sun. Scotland, no sun in the winter but lots wind all the time. Those places renewables aren't problematic.