solar location on Truck camper
my truck camper has a slanted roof over the bed, and flat over the rear section. I am looking at fixed position mounting of solar panels. (mostly being used in East coast central US during summer). ...
Forum Discussion
DWeikert wrote:Jfet wrote:DWeikert wrote:
This is very dated information. Most solar panels today use blocking diodes so shade over a single cell only affects that cell, not the whole panel.
Bypass diodes, and generally they only use about three, which means partial shading can still shut off 1/3 or more of your panel (depending on the orientation of the shadow).
An exception would be the Unisolar rollout, where they do indeed bypass each cell panel.
You're right, they're bypass, not blocking. Still, I think your info is dated. For example, the Kyocera 140w panel I installed 2 years ago has 8 bypass diodes.
It will of course depend on the panel (8 diodes might mean 4 per string on a 140W). The bypass diode will remove the current block, but also reduce the voltage output. Reduce it by much and you will not have enough to charge the battery. Put a 2x4 across your panel on a sunny day and see what it does. Amorphous Si panels like the Unisolar are less susceptible to shading generally (but also have less output/area).
