Solar - Series Wiring with Bypass Diodes

Question

Hi,From the many discussions surrounding the benefits and drawbacks of series vs parallel solar wiring, I'm curious why I have not encountered anyone suggesting using bypass diodes between solar panels when wired in series?It seems almost unanimous that bypass diodes are a good thing when installed in a solar panel, so why not install them between panels?I recognize that it will complicate the wiring, but the benefit may be substantial. Has anyone tried this?LB

2oldman · Answer

If the diodes are properly installed in the panels what you're suggesting should be unnecessary.

time2roll · Answer

Most of the larger panels (24v) have the bypass diodes.As long as you are going series you may as well get the lower cost 24v panels.

mrwizard · Answer

moved from technology corner

ca_traveler · Answer

Installing them between the panels adds about 0.5V per diode to the controller input - not desirable at all.

Bypass diodes installed in a panel are wired to bypass only a portion of the panel. For example a 6x10 panel with 3 bypass diodes - each diode would bypass 20 cells. ie A 30V panel would now produce 20V - 0.5V = 19.5V for example.

wintersun · Answer

Regardless of the diodes if the panel in the middle of the run is in the shade it is going to reduce the current from all the upstream panels going to the controller. Wiring in series helps if you plan to use the manufacturer's 12ga wiring to reduce current loss but otherwise it makes no sense for an RV installation. Shade can come from a tree or even items on the roof like an antenna, refer vent, luggage rack, AC cowl.

Forum Discussion

Solar - Series Wiring with Bypass Diodes

5 Replies

About Technical Issues

Related Content

Fleetwood Angler wiring

2005 SixPac D850 Wiring

Bad tail light wiring

Parallel vs Series, 10awg wire

bypassing the battery