Solar power functions by capturing sunlight and converting it into energy. Therefore, if a solar power module is blocked from sunlight, it cannot function properly. That’s why many solar roofing systems – such as Timberline Solar™ – require optimal exposure to sunlight.

If a roof is heavily shaded by a permanent obstruction like a building or thick forestation, and sunlight is blocked regardless of the position of the sun, a solar installation is not advised. This is known as “hard” or “extreme” shading. If a roof experiences light shading, mitigation efforts may be taken to allow for solar installation, depending on the severity of the shading. Examples of light shading include a single tree whose shadow moves depending on the sun’s position (known as “sweeping shade”) or whose canopy is thin enough for sunlight to perforate. Maximum energy generation cannot be achieved unless no shading is present, but the value of installing solar roofing even in the presence of shade can change from project to project, and from house to house.