

I see what you’re getting at here. The solar constant is the solar constant. If you’ve got a perfect angle to the sun, you should be getting the same amount of power regardless of latitude. I mean I suppose it’s possible there might be a slight attenuation with the sun at a lower angle due to there being more atmosphere to traverse? Otoh solar panels don’t function as efficiently at high temperatures, so it’s possible they may be more efficient in some cases.
But you have to consider that averaged out, you’re looking at shorter daylight hours overall at high latitudes, even if there are periods in mid-summer when days can be super long, so that’s a consideration. So yes, the panels should pull in similar amounts of power while the sun is up, but it’s not up as much.
I saw one of these on display at the Musical Instrument Museum in Phoenix AZ, but never heard one played. It’s so huge you can’t reach those frets at the top there, so the inventor had to come up with a keyed mechanism you see the guy working in the photo.