Solar Panel Diode Installation

For solar panels we recommend you put one blocking diode on each solar panel inside an abs project box the diode needs to have a voltage and amperage rating above that of the panel.

Solar panel diode installation.

If you have two 175 watt panels each at 42 volts you will need two 8 amp 45 volt diodes. A solar panel it a grouping of cells in a series parallel configuration of one form or another typically inside a housing. By pass diodes will not be of use unless panels are connected in series to produce a higher voltage. A blocking diode is required in each series string of solar modules between the modules and regulator battery to prevent current flowing back through the modules when the modules are shaded or during darkness.

Store bought panels will typically have a protection diode already in place. Namely the silicon solar cell array the voltage or charge regulator a blocking diode and a storage battery bank. Now if one panel is shaded the current produced by the unshaded panel can flow through a by pass diode to avoid the high resistance of the shaded panel. The blocking diode acts like a one way valve allowing current to flow only one way out of the solar module.

If your panels are a grouping of other panels then you won t need a diode. 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 is where by pass diodes come into play as shown in the diagram to the right. The basic solar photovoltaic power system commonly used in outback australia shown in fig.