Re: [A/S] solar panels

[Jim Dunmyer <jdunmyer@xxxxxxxxxxx>]

Dean,
  Actually, mixing panels really isn't all bad. Ideally, they should be 
of the same kind (crystalline or amorphous), but I'm not sure even that 
makes much difference. Solar panels are basically a constant-current 
device, giving X amps from short circuit to nearly open-circuit voltages.

The Solar Boost controller was tested by Home Power magazine, which you 
can find online at http://www.homepower.com. They listed it in their 
"Things That Work" catagory, so it does function as advertised. The 
basic operation, as I understand it, is to run a DC/DC converter, using 
the OC voltage of the panels, "stepping it down" to what the batteries 
require. Standard controllers simply throw away that extra voltage, in 
effect. The maker claims that use of the SB controller will often 
eliminate the need for one panel, paying for the unit.

Regarding "normal days": That's sunny, with no clouds to amount to 
anything. As you've seen in the pics of our system, there's an analog 
meter in series with the panels, and it's interesting to watch it during 
the day. It will vary all over the map as clouds come and go. Amorphous 
panels are somewhat better about operating in partial shading, but give 
less power in peak sunlight; who knows which is better overall? I do 
know that our panels don't do much of anything when it's cloudy, let 
alone raining. However, we do have enough excess capacity in both the 
panels and the batteries (2, Group 24 "RV/Marine/Deep Cycle") to weather 
a couple or 3 rainy days, yet catch up fairly quickly when the sun does 
finally shine brightly. We've use the system for 2 seasons, probably 
50-70 days total, with the longest stay being 3 weeks, and never came 
close to running low on power. And, the trailer doesn't usually get 
plugged in at home, either.

I've become quite the Generator Nazi, I *hate* those noisy, stinky 
things in crowded camping areas. Most of our Summer camping is at 
antique engine/tractor rallies, etc., usually for 3-7 days at a time. 
The folks who attend only one of those per year tend to not know how to 
operate even a day or 2 w/o shore power, so carry their hardware store 
Generac, et. al. genset so they can make coffee, etc. Those things are 
TERRIBLE for noise.

Your system, with 4 panels, should allow you to never consider shore 
power unless you want/need to run the A/C.

                                     <<Jim>>