Blocking diodes for paralleled panels?

[john61ct]

No.

The issue is overall efficiency, not damage to panels.

[Axel_G]

Originally Posted by roland stockham

On a slight thread drift. I have 2 100w panels rigged in series either side of the boat to a single MPPT controller. often one has indirect sun when the other has full sun. One of the bypass diodes (2 per panel) has blown and had to be removes as it was shorting the panel section.
Can someone clarify if there is ant danger of burning out cells on the panel with less light. Very hard to get blocking diodes here!

This is a very bad setup anyway. I would put them in parallel and remove the diodes completely.



Putting these two panels in series reduces the current to the amount the shaded panel delivers. In this case the shaded panel was obviously completely bypassed by the diode, so did not deliver anything and it seems the diode was even overloaded. At least you got the current from the god panel but still less than possible.



In parallel the MPPT controller will still adjust so that the combination of the two panels will deliver the optimum power.

[roland stockham]

OK. I will see if I can get some pigtails to do that, still learning about solar but this setup does seem to work. Max output is only about 65% of panel rating so room for improvement. One yhe plus side I get output from about 1hr after sun up on all point and at all angles of heel. Panels are arranged so I can almost always point one to the sun without the sails blocking it. Was difficult as I have very limited deck space so the are set up as 'wings' on the stern arch (top has radar & aerials on it)