Key design features of the SunPower high efficiency modules
Typical crystalline silicon modules use bypass diodes to protect cells against large reverse-bias voltages that can occur as a result of partial module shading or a problem with a cell. SunPower cells have advantageous breakdown behaviour at -5.5 volts (V) that is reversible and uniform, thereby eliminating the need for bypass diodes to protect the cells. While bypass diodes are not required for cell protection, diodes are included in modules to increase energy delivery under certain partial shading conditions and to provide comfort to customers who are used to diodes being present. Three diodes with 8A rating are included in the 72-cell module in a junction box tested under the present and the recently-announced IEC testing standards.
Cell-cell interconnect cloak
The cell-to-cell interconnect in the modules is visually shielded from the front (patent pending), because SunPower cells have no metal or other visible features on the front side, the use of an interconnect cloak results in a uniform appearance with no harsh reflections.