Solar Panel Bypass Diode Installation

Learn how and why blocking diodes and bypass diodes are used.

Solar panel bypass diode installation.

Primarily the bypass diode improves the overall system performance of the solar module. In multi panel pv strings the faulty panel or string has been bypassed by the diode which provide alternative path to the flowing current from solar panels to the load. Solar modules with bypass diodes are manufactured because of two reasons. Bypass diodes inside a junction box of a solar panel provide a low resistance path for the current go around a series of solar cells that have been shaded.

Panels are made up of solar cells most commonly 60 cells. In a string inverter system panels are connected in series. In simplest terms a diode can be understood as a two terminal electronic device which allows electrical current to pass in one direction. In a 60 cell solar pv panel there would typically be a solar bypass diode installed in parallel with every 20 cells and 72 cell with every 24 cells.

A blocking diode and bypass diode are commonly used in solar energy systems and solar panels. The diode is wired in parallel with the cells. These cells are connected in series with three bypass diodes installed on each sub string of 20 cells. Now let s consider what happens if one of the panels in the above diagram is shaded.

Bypass diode in a solar panel is used to protect partially shaded photovoltaic cells array inside solar panel from the normally operated photovoltaic string in the peak sunshine in the same pv panel. Diode and unidirectional flow of current. Bypass diodes are used to reduce the power loss solar panels experience due to shading. The voltage increases for every panel you have in the string while the current remains the same.

Those shaded solar cells become consumers of electricity instead of producers. This causes the solar panel to heat up and have severe power loss. Blocking diodes will be of benefit in any system using solar panels to charge a battery. Because current flows from high to low voltage when a solar panel has cells that are partially shaded the current is then forced through the low voltage shaded cells.

This causes the solar panel to heat up and have some power loss.