What is the Shading Factor?
The shading factor measures how much sunlight is blocked by nearby obstacles, directly impacting your solar panels' energy output. A lower shading factor means more sunlight reaches your panels, maximizing energy production.
For example, if a tree or building blocks 20% of the sunlight at a given point, the shading factor at that location is 20%. The goal is to minimize this value to optimize system performance.
Shading Factor vs. Shading Loss
It’s important to distinguish between shading factor and shading loss:
Shading factor is the fraction of irradiation blocked before sunlight is converted into energy.
Shading loss refers to the actual electricity loss due to shading after sunlight has been converted into energy.
While these values are often treated as linearly connected for simplification, real-world shading losses may vary. Factors such as partial shading of strings and the use of optimizers can influence shading losses beyond what the shading factor alone suggests. In Expert, we provide a straightforward linear approach to keep calculations clear and predictable, ensuring easy integration with project simulation.
Where is the Shading Factor Used?
How is the Shading Factor Calculated?
Shading factor calculations involve three key steps:
Data Collection: The system gathers details about buildings and obstacles, while horizon data and direct and diffused irradiation come from PVGIS—a trusted solar data source developed by the European Commission's Joint Research Centre, ensuring accuracy based on decades of validated satellite and ground measurements.
Point-by-Point Calculation: The software calculates the shading factor for each point on the roof or panel.
Shading factor: These outputs are used for shading factor visualization in the 3D panel layout.