But anyone who has read a book about designing a home solar system can tell you that all of the literature tells you that you have to pick the location of your panels carefully so they aren't occluded by trees over part of the year because the power losses due to occlusion are significant and can make a system non-viable and non-economic. From the book I read [0] (although mine is the 2015 edition), not planning for obstacles is the #1 reason solar power system designs fail.

I'm not sure why they didn't hire an experienced engineer for this multi-million Euro project.

[0] https://www.amazon.com/Solar-Electricity-Handbook-installing...