Roof Considerations for Solar
What Makes a Good or Bad Roof for Solar Panels
For roof mounted solar systems, which are the most common for residential systems, there are three main things to consider: shading, configuration (complexity), and orientation (aszmith).
Are there things blocking the sunlight to your roof? How much sunlight is getting to your roof?
What direction does your roof face? South is ideal but east and west work very well too.
Is your roof relatively free of items that would obstruct solar panel placement, like vents or dormers?
Each of the categories above are shown in detail below.
Shading is one of the most important things to look at for your roof. The images below are taken from Google’s Project Sunroof, which is a very easy and free tool/website to use to find out how much sun your roof gets all year round. Below is a good look at the difference between full sun, no sun and the middle ground.
No Shading is Ideal
This a roof that has no nearby shading items or on roof shading items on the south, east, or west side.
Some Shading is Ok
Some shading is ok; it depends on how close and or tall the object is. Shade readings will show what solar is available.
Heavy Shading is Bad
This a roof that won’t be a good fit for solar. Even though the roof gets some sun, it’s not enough.
Orientation for Solar
Orientation is the direction your roof faces in relation to the sun.
South Facing Is Ideal
A south facing roof space will have the potential of getting the most sun, depending on shading of course.
East & West are Good
East and west facing roofs will miss out on a little bit of the sun, but still provide a very good amount of power.
Southwest & Southeast
These roof surfaces will miss out on a little bit of the sunlight but are very good options
Roof Configuration or Complexity
A south facing roof space with little to no obstruction is ideal. On the roof above there is a flat roof with no vents or dormers facing south. That’s about as perfect as it gets,
If the useable roof space has some obstructions, like dormer, they can be worked around. Above, the main roof space is ok, and panel placement away from the dormer will minimize shade effects.
A roof with very little open space that is broken up into many faces, with many dormers and other obstructions doesn’t work well for solar. It’s very hard to get solar on to roofs with this much complexity.
So what if your roof isn’t right for solar?
If you have enough space in your yard or on your land, you can install a ground mounted system. Learn all about these systems next.