Design references

A Guide to Photovoltaic (PV) System Design and Installation (365KB pdf)
The purpose of this document is to provide tools and guidelines for the installer to help ensure that residential photovoltaic power systems are properly specified and installed, resulting in a system that operates to its design potential.

Photovoltaics: Basic Design Principles and Components
U.S. Dept. of Energy's introduction to basic design principles and components of PV systems to aid consumers in discussing these systems knowledgeably with an equipment supplier or system installer.

Drawings

Winter Shade - Long Orientation (29KB pdf)
Shows minimum spacing between panels on a flat roof.

Winter Shade - Short Orientation (31KB pdf)
Shows minimum spacing between panels on a flat roof.