Roof Orientation and Pitch RequirementsThe direction your roof faces plays a central role in how much electricity your system generates throughout the day. Because many traditional solar panels are wired in series, a shadow over a single panel can drag down the performance of the whole string. Solar panels and mounting systems add significant weight, typically around 15 to 20 kilograms per panel. Quick Roof Pre-Check Before Calling InstallersBefore you contact local solar installation companies, take a few minutes to complete a quick self-assessment. Adequate load-bearing roof timber that shows no signs of rot, sagging, or water damage.