Just Starting Solar Research

mitch5252 wrote:
OP HERE...

I think I have found a starter bunch of solar equipment from Renogy. I plan to order one 100W panel and other stuff to try my hand at compiling a working system...hahahaha.

If, in the future, I want to add a second panel, 1) does the manufacturer have to match the original panel, and 2) must the wattage be the same (100W for first panel, therefore, 100W for second panel)? Or can I add, say 150W to my 100W?

Also, I do not want this panel on my trailer's roof. What methods do I have available for placing it on the ground and being able to move it to follow the sun.

You can add any size panel to another in the 12v panel sizes. It is better if their Vocs are fairly close--most are in the 21v range but the watts size doesn't matter. I have paired an 80 and a 130 ok, the 130 and a 120 ok and now have the same 130 and two 100s ok.

Be aware of controller amp size for running these 12v panels. You need the expected max amps of the panel (use its Isc) and allow 20% margin for sometimes getting more. A 130w will gat about 8.2a and it is all proportional so a 100 would get 6.3a eg.

It boils down to a 20a controller will be maxed with 250w of panels and still have that 20% (doesn't have to be exact) Since controllers jump in price as you go up in size, it could be worth getting a 30a controller right off and then no "issues" if you add any panels.

I got caught with my 20a controller good for the 130 plus 120, but then traded the 120 for two 100s so now the single 20a controller was too small. (expected amps 21a with no margin) Rather than get a 30a controller I got a second 20 (much cheaper than a 30 and now use two 20s in parallel. Easier to get a 30 in the first place.

You can prop up your portable panel on the back of a lawn chair and just move it to face the sun whenever you get the urge, or you can use a "dolly" with wheels on it. One thing is you want the bottom a few inches off the ground to clear grass etc that might shade the bottom, so you can use a log to sit it on with a stand behind it to prop it up, or just lean it against the RV. The hard part is stringing the wire from the controller to the panel out there so you have enough wire and don't keep tripping over it.

Locating the portable panel is not that simple either. Your RV makes a big shadow part of the day in over half the day in summer, less than half in winter, especially with the slide and awning out. So you might need to place the panel farther out and not have enough wire. Or else where the panel needs to go is over in the next site from yours or the middle of the campground road! It is all part of the fun picking your parking spot and direction for the RV so the sun gets on the panel with the least amount of work on your part.