Embed Notice

I am looking at a house which has a roof which would be suitable for solar panels. The roof is south (ish) facing, which is nice. However, there are some tall trees in the garden behind. In the Google Maps satellite view, the roof is *not* shaded, and in fact the shadows are a decent "gap" away from the house. But I'd rather know with a bit more certainty.

Does anyone know of a tool/web service/etc I could use to simulate shadow length? And/or just a rule of thumb? Or have any other thoughts?