I made a greenhouse this year and i “screwed up” royally. I only had enough glass to do a lean to against a fence but by the time I put cinder block under it, it was a lean away instead of a lean to. But it worked. And after a while, I realised that it was working really well. I tried to explain how and why it was working so well and got some help online. Anyway, I found sollumis.com which puts the sun on a google map or pic of your house.
This could be really useful when planning which windows to use for your windowfarm. It could be really useful to people but I don’t know who provides it (which bugs me). I also found some neat info about how glass transmits and reflects light and about how much time the sun spends north of the east west line. Low in the sky but still shining! In Nottingham England around June 25 it was about 3.5 hours in the north east sector, then crossed into the southern sky and spent 10.5 hours there before crossing the east west line again and spending 3.5 hours in the north west sector before setting! That surprised me and might surprise you too! Anyway, check out the “instructable” if some of this interests you. It may be indirectly helpful to your project http://www.instructables.com/id/Design-your-greenhouse-Lean-away-Better-than-l/
Brian.