THE USE OF BLOCKING DIODES WITH THE THREE TYPES OF SOLAR PANELS

This is interesting information:

There are primarily three types of solar electric panel technologies being used today.
1) SINGLE CRYSTALLINE 2) POLY CRYSTALLINE 3) AMORPHOUS
How should blocking diodes be used with each type of panel?
SINGLE CRYSTALLINE panels are glass covered rigidly mounted panels. They have a low nighttime back flow of
power from the batteries. The loss at night is actually a little less than the amount of loss you get by adding a
blocking diode to the panel. On a single panel system you may get more out of your panel if you do not use a
blocking diode on these type of panels, On multiple panel arrays, blocking diodes should be used, especially
on unattended remote systems, to guard against a failed panel. Because they are glass covered, a stray falling
branch, hailstones, a child with a rock, or bored hunter could bring the entire system down by damaging only one
panel.
POLY CRYSTALLINE panels are also glass covered rigidly mounted panels. They have a slightly higher
nighttime draw of power from the batteries when compared to single crystalline panels. The loss at night is near
equal to the loss you get by adding a blocking diode to the panel. You may or may not get more out of your panel
by using blocking diodes on these type of panels, On multiple panel arrays, blocking diodes should be used,
especially on unattended remote systems, to guard against a failed panel. Because they are glass covered, a
stray falling branch, hailstones, a child with a rock, or bored hunter could bring the entire system down by
damaging only one panel.
AMORPHOUS panels are a very different when compared to the other types of panels. They have a fairly
substantial nighttime draw of power from the batteries when compared to single crystalline panels. The loss at
night is higher than the loss you get by adding a blocking diode to the panel; in addition, these type panels could
actually draw enough power from the batteries at night to damage themselves if diodes are not used. To
compensate for the diode loss, most amorphous panels have a higher operating voltage, to make up for the
voltage drop losses of the diode.
Blocking diodes should be used on all systems when panels have been connected in series to charge 24V,
or higher voltage batteries, or when using an inverter on the system. Inverters can cause voltage spikes
as high as 60 volts on the DC positive wires. This is enough voltage to damage most solar panels.
In conclusion; blocking diodes should be used on all systems except, one panel single crystalline 12V systems. If your system
is so marginal that using, or not using diodes will make the difference, consider adding another solar panel to your system