A couple friends are working on a grant to build a high-performance house on our campus.
They want to put solar PV panels and a solar thermal domestic hot water collector on the house's roof, but they weren't sure how to configure everything to prevent one panel from shading another.
Doing this kind of analysis is fairly straightforward in Autodesk Ecotect. I was given a 2D .dwg file, so I just had to rotate each block of panels up 20° using a 2.5D CAD program. Then I imported as a .dxf into Ecotect. Not seamless yet, but not terrible either.
The graphics below show the percentage of time each panel spends shaded throughout the year, between 9 am and 2 pm (peak insolation window) at our location and altitude here in Boone.
Blue panels are never in shade, while an entirely yellow panel is shaded 15% of the time.
Ecotect is great because I can do this analysis without wasting time on a detailed physical model. I spent less than an hour on this virtual model, and I'm brand-new to Ecotect. The models aren't perfect--for example, the panels lack thickness, which would impact shading geometry slightly. But now my "clients" can determine which configuration to focus on for a more comprehensive analysis.