Are you saying it's cloudy for four months straight?
And the panels are still making power during the winter.
A detailed chart would be nice but a good starting point to imagine is 60-70 days that average 50% solar power and the rest of the year is full solar power minus a couple particularly bad days.
Edit: In winter, in denmark, the amount of sunlight you get per square meter of flat ground is absolutely awful. But the amount of sunlight you can catch on a highly tilted solar panel is still pretty good, about half of the average output. So if you space them properly and overbuild based on the average, the 90% number isn't crazy.
Are you saying it's cloudy for four months straight?
And the panels are still making power during the winter.
A detailed chart would be nice but a good starting point to imagine is 60-70 days that average 50% solar power and the rest of the year is full solar power minus a couple particularly bad days.
Edit: In winter, in denmark, the amount of sunlight you get per square meter of flat ground is absolutely awful. But the amount of sunlight you can catch on a highly tilted solar panel is still pretty good, about half of the average output. So if you space them properly and overbuild based on the average, the 90% number isn't crazy.