Wire Gauge Required Question

tenbear wrote:
Interesting! Thanks for doing the experiment. I'll be waiting for the results with a load on the controller.

I was also wondering what effect a small area of shade, like the shadow of a vent on one of the panels does.

I believe what will happen is that the cells that are shaded won't contribute much to current, AND will increase the output impedance of the panel. So shade has two effects, reducing the available current and at the same time causing the output voltage of the panel to decrease more under load because of a higher impedance. Solar panels don't come close to being a true voltage source. A source that will provide a given voltage regardless of load current. they are more like a current limited voltage source with also a relatively high output impedance for the typical output current.

Now, since panels have anywhere from none to a large number of blocking diodes to effectively bypass shaded cells, how blocking a portion of a panel compares to blocking a whole panel in an array I don't know.

An interesting experiment for a given panel type would be to block 1/2 of each of two panels in series and compare output power to blocking one whole panel in a two panel series array and then compare the max power. My first guess would be that blocking a whole panel will yield higher output power than blocking 1/2 of each of two panels. But who knows, anyone want to try the experiement. And the results would only apply to that panel construction. different numbers of blocking diodes etc. per panel could have different end results.