Comment by 3eb7988a1663

You can look at maps of solar insolation[0] - these give you typical levels of solar input. There is of course weather variations, but the long-term trends should be consistent.

One thing that can catch me is how much more north Europe is than basically all of the USA. The general solar insolation is worse, yet they are still doing a healthy business of solar. The panels are so cheap that even if you are in a crummy environment, you can just add more.

[0] https://en.wikipedia.org/wiki/Solar_irradiance