Solar strategy in the east

Almot wrote:
I think the choice of MPPT vs PWM will only be important if they choose ~200W portable - in a full sun MPPT will over-perform PWM.

If they decide to cover the roof with amorphous panels and try making "something out of nothing" while in the shade - I like how BFL calls it :) - then the difference between PWM and MPPT won't be that obvious.

This looks like 2 choices here - medium size portable (likely a set of 2 in series) or maximum size on-roof amorphous in parallel. In any event they will need at least 300 AH battery bank and limit their MW use.

Can't find the link now, but I was reading that if it is sunny where you use solar you don't get much with MPPT over what you would get with PWM so might as well save money on the controller and get PWM.

OTOH if it is often cloudy they said you get more value from MPPT so go that route. I am not clear on what that means for the OP in this thread between "cloudy" "low light" "off angle sun when sunny and panel not pointed" and "shaded in trees with light coming through" if these are all the same thing for applying that advice.

I just can't see how MPPT and 24v panels or 12s in series can do better in low light or start charging earlier in the day than PWM. Seems bogus to me. The panel cells are the same.

My 12v system "wakes up" early too. "Starts charging" might be the clever wording. That would be when solar amps in exceed discharge amps out. Half of that depends on what you are running in the rig at the time.

Whole thing seems dubious IMO. Perhaps in a couple months I will find out when the new 24v panel and MPPT controller gets deployed and I can compare that with what I am used to with PWM.