1. The Roof (Azimuth)
A west-facing roof isn’t a dealbreaker anymore
Let’s start with the roof. An ideal roof has a large, uninterrupted surface facing south, southeast, or southwest. However, given advances in solar module technology and efficiencies that make them more affordable, a purely due-south roof is no longer a prerequisite. A well-producing solar home should have an orientation or “azimuth” within 90 degrees of true south. The closer the solar azimuth is to 180 degrees true south the better the system will produce. Roof angles are also something to consider. A roof pitch between 5 and 12 is ideal. The lower the slope, the less production you will see in the winter.
A good roof for solar is an empty roof; uninterrupted. That means keep your chimneys, vent pipes, dormers, and skylights away from that nice big southern expanse! We can work around these things if we have to, but if you want to maximize production, have wide-open spaces.