I see quite high estimates (e.g., 'Estimated First Year Production: 14,815 kWh') for a 9 kWp installation. In my case, having a complex on-roof installation (with a flat surface, shading issues, etc.), I can barely count on a 1:1 ratio. For example, with a 10 kWp installation, I can barely achieve 9,000–10,000 kWh per year.

Of course, the output depends not only on the specific setup but also on geographic location and associated factors like weather conditions.

I'm curious to know how effective other installations are (FYI @ksteem @steevc).