My house faces 15 degrees west of south and i have a small 1.3kw array
I have discovered to my shock that my new neighbors spent 1/2million dollars next door for the existing house to tear it down and put a mini mansion 14ft from my east wall
it will be 68ft long and 40ft high.
(all zoneing code legal)
my house is 15ft high and 25ft long and my panels are on the roof.
Is there a FAQ or a cheap program or similar to let me find out how much I will be shaded?
I am unsure how much a hit my panels will take.
(yes i have talked to zoning board, planning comission, mayor councilmembers, county council member, state senator, head of SEIA and a few others.
response "hey thats tough"

Wow , that a though one

Well most zoning has minimum setback requirements , 14ft seem close. Same on height.

I'm not sure about solar access rights , in Arizona , there as such rights , read about that on the RE-Wrenches list. I assume your in a very desireable location (beach front ?) , your only option might be to take the money and run (Sell out to someone who want to build another mini mansion)

You could always file a lawsuit for an injunction to stop the construction , but the legal route would be expensive ...

The thought occured to me that perhaps you could talk your new neighbor in becoming more sustainable by going solar like you. Now, new construction of most mcMansions have all sorts of hips, angles, small dormers and what not jutting out, but perhaps you'll get lucky and find that their roofing plans can accommodate a good sized system for the McMansion and placement of your one-square (approx 100 sq ft) array on their roof as well. If they're worried about esthetics, there's a handful of companies out with tile and shingle PV products.

The other alternative, which is what I had to do, was to install my 300 sq ft array on my garage behind the house. This was because my wunnerful neighbors to the south decided to build up a story, and their wall is only SEVEN feet from the prop line. Now this might not work for you if you've one of these houses with the large front gaping-mouth garages integrated into your house.

It's probably the only shots you got, other than expensively going up yourself.

On my lot, setback between houses is 3' from the line, as of 1999 when I did my 2 story addition. It'd sure chafe my hide too, to have something pop up and shade my panels. Mike

i feel for you guy, but though you will get some summer evening shading, all isn't lost. you are only 15 degrees off of south and that'll be your saving grace and that's assuming the pvs face that same 15 degrees west of south. in the summer most of the sky lights up even though a pv isn't at an optimal angle, the intensity makes up for quite a bit of it.(i believe the term to be backradiation) this is why a pv doesn't lose that much when it doesn't track.(15% comes to mind) make no mistake about it though that you will lose some sun.
now the winter angle will see it all without interference as the sun will not venture as far west, or that far east for that matter. it may be advantagious to bump the pvs a few degrees more towards facing south if at all possible, but do not try to gain all 15 degrees as you may then find the forward pvs shading the ones in the back, especially in the winter months when you need it the most.