There’s an unfortunate reality many solar system owners only come to learn once they’ve installed solar panel(s) on their roof: Shade happens. Not only is it inevitable when wrongly positioned, it comes with a significant impact to the operation and efficiency of your solar panels.
The good news is, most solar panels can actually minimize the impacts of shading. The design and engineering that goes into panels truly makes a difference in the amount of energy the solar panel system will produce.
Here are a few key scenarios to consider.
Current flows through the panel in a continuous, serial circuit. Any interruption to this flow can have detrimental effects on panel effectiveness. For this reason, the panel is typically partitioned into three distinct electrical zones which allows the panel to bypass obstructions to energy flow, should one occur
The shade from leaves can seriously reduce power output from your panel. When a leaf is placed over a cell of a panel, the cell can no longer generate power nor can it properly pass power between adjacent cells. Unable to function properly. The obstructed cell forces an entire electrical zone of the panel to shut down until the leaf is removed. That means about 33% of the panel shuts down, which translates to about 33% loss in power.
However, panels are now engineered to keep energy flowing in independent, parallel rows. Each row of cells employs flexible, redundant paths for energy to move from cell to cell, limiting the impact of obstructions on the panel surface.
When the shadow of an object or structure is cast over the surface a panel, there is an immediate impact on the panel. As the shadow is cast on the long edge of the panel, the panel will shut down one of its three electrical zones to bypass the shading. Just like the spot shadow from the leaf, we see a 33% drop in power.
As the long edge of the panel becomes shaded, power loss is in proportion to the shade. This means that if only half of the first row of cells is shaded, the other half of the cells in that row are still producing energy, and the panel is operating at 92% of its power rating.
In a case where the panel is installed in portrait orientation, shading objects will have a significant impact over the panel. As shade is cast on one part of the panel, it quickly affects all three electrical zones, completely shutting down the panel.
- Dirt or Dust
Just like shade, dirt or dust do have quite some impact on the effectiveness on your panels. In an unfortunate event where some debris finds its way to tour panels, its effect is immediate just like that of the leaf. In this case, the weight and the force at which the debris lands on the panel can harm the panel. Excess dust covering the panel (especially in seasons like harmattan), will shade panels from sunlight overtime
Simple tips for longevity and effectiveness of your panels
- Panel orientation with respect to possible shadings
- Ensure the panel is cleaned periodically by professionals
- Install panels facing south