Solar Panel Bypass Diode Installation

Now let s consider what happens if one of the panels in the above diagram is shaded.

Solar panel bypass diode installation.

In a string inverter system panels are connected in series. Diode and unidirectional flow of current. 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. The voltage increases for every panel you have in the string while the current remains the same.

This causes the solar panel to heat up and have some power loss. Blocking diodes are usually included in the construction of solar panels so further blocking diodes are not required. These cells are connected in series with three bypass diodes installed on each sub string of 20 cells. 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.

Bypass diodes are used to reduce the power loss solar panels experience due to shading. 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. 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. This causes the solar panel to heat up and have severe power loss.

The diode is wired in parallel with the cells. In simplest terms a diode can be understood as a two terminal electronic device which allows electrical current to pass in one direction. Those shaded solar cells become consumers of electricity instead of producers. Primarily the bypass diode improves the overall system performance of the solar module.

Panels are made up of solar cells most commonly 60 cells. A solution for partial shading and soiling a shaded or polluted solar photovoltaic cell is unable to pass as much current or voltage as an unconcerned cell. Solar modules with bypass diodes are manufactured because of two reasons. Recently some solar panels are being manufactured by the cells divided into groups with a built in bypass diode in that group.

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.