The solar module is made up of a number of solar cells connected and packed to each other in a certain pattern. The extent of the closeness of the solar cells in the module is defined by the term Packing density.
In other words, it tells how closely the solar cells are packed to each other. The higher value of the packing density means that there is less empty space between the solar cells while a lower value of the packing density signifies more empty space between the solar cells or the solar cells are loosely packed. It affects the output power and the operating temperature of the module.
The rear sheet on which the solar cells are embedded is white in color and when the light falls on the white surface, it is reflected and marginally improves the efficiency of the solar cells.
Different types of Packing Densities
The packing density depends on the shape of the solar cells whether it is round, pseudo-square (semi-square) or square.
The packing density in this context particularly talks about the wafers-based module but not the thin film modules. As of today, the wafers-based technology supports the 90% of the modules.
Although, the efficiency of both the mono-crystalline modules and the poly-crystalline modules are nearly the same, the multi-crystalline solar panels are preferred over them and are widely in use because of their higher cost and the lower packing densities of the mono-crystalline modules.