Hey Capt,
Sounds like you need more LEDs! Gotta find a way to use that power.
You are using a 'ghurd' controller?
Simply add another IRFZ44N, and add a heavy duty blocking diode.
PV positive to the fet drain, and the diode. Out of the diode to the battery positive.
PV negative to the fet source, and battery negative.
Fet gate connected to the other fet gates and controller.
When the controller dumps, the fet turns on, the amps from the new PV are shorted through the fet.
The blocking diode stops current coming from the battery (so the fet won't short unlimited battery amps)
The new PV's amps don't go into the battery or dump load when the circuit is dumping.
The dump load does not need expanded, or changed at all.
I have sketches.
I recall at least Dr Dave and Independent posted stories doing it this way (solar with no dump load).
http://www.fieldlines.com/story/2008/5/4/41311/92374
http://www.fieldlines.com/story/2008/6/22/21540/7547
No reason to shade it at all. I don't believe it would hurt the PV. I am too lazy to be bothered doing it.
Automatic is good. :-)
G-
