Not every roof is equal when it comes to solar, and a short assessment early on saves a lot of guesswork later. Four factors matter most: orientation, shading, available space and the condition of the roof itself.
Orientation describes the direction a roof surface faces. In South Africa, north-facing surfaces generally receive the strongest annual solar exposure. In Canada, south-facing surfaces generally receive the strongest annual exposure. East- and west-facing roofs can also work well, especially when their production pattern matches the property’s morning or afternoon electricity use.
Shading is the quiet performance-killer. Even partial shade from a tree, chimney or neighbouring building at certain times of day can reduce output. Good design accounts for this, and in some cases equipment choices can lessen the impact of unavoidable shade.
Finally, space and structure. There needs to be enough clear, sound roof area to hold the number of panels your goals require, and the roof should be in good enough condition to carry them for the system’s lifetime. If a re-roof is due soon, it is usually worth doing first.
