Does roof angle and direction effect Solar Systems?
The short answer to this question is, yes. Roof angles between 12 – 45 degrees allow most PV systems to operate at near peak levels. Although the preferred installation direction is south, roofs facing SW, SE and even east and west are good candidates for PV. Solar power output decreases proportionally with a horizontal angle, or “azimuth,” greater than 15° from due south. Most people are surprised to find out that the angle of a PV panel does not have to be set at a perfect tilt and exact south direction. Although there is a set angle when optimum efficiency is achieve. The approximate angle of peak efficiency for a perfect south installation is equal to the latitude of the location (on summer solstice). Because the sun swings with the seasons this angle varies, but modern PV panels operate at 95%-100% efficiency with angle variations up to 35 degrees. While using PV modules is very simple, the mathematics describing their angular relationship to the sun is very difficult. Latitude of
