Shading

shading is a problem in PV modules since shading just one cell in the module can reduce the power output to zero

Shading of a Single Cell

The output of a cell declines when shaded by a tree branch, buliding or module dust. The output declines proportionally to the amount of shading. For completely opaque objects such as a leaf, the decline in current output of the cell is proportional to the amount of the cell that is obscured.

Move the grey rectangle over the solar cell. The current is reduced by the amount of shading.

Shading of a Module

The cells in a module are all connected in series. Shading a single cell causes the current in the string of cells to fall to the level of the shaded cell.