Solar - Poly or Mono?

IMO if you're concerned about partial shading, you'll get more benefit by buying panels with multiple bypass diodes (like Kyocera) than worrying about poly vs. mono.

I just installed four 270 watt mono panels on our truck camper (it has a lot of roof space) and am amazed at the output in non-ideal conditions.

Seattle, early March, sunny: 620 watts peak output at noon
Seattle, early March, foggy, raining: 54 watts peak output at noon
Seattle, early March, overcast: 263 watts peak output at noon

I was not expecting nearly this much. I may be a bit over-paneled for our 24V 125AH battery bank :D

I think you will like those panels. I did.

I noticed the polys are larger to make up for the reduced efficiency so that you will get 100 watts from either. I suspect that I could add a poly later if I needed more charging as 200w is going to be barely adequate. I have the 100w portable to supplement with anyway.

I bought the 2 polys from amazon for 257.00 and so far so good. But havent hads them out in real world testing.

Well, Amazon had a nice price for a pair of the Renogy 100w Mono panels, so I placed the order.

Mono panel
Poly panel
I plan to go with 2 or 3 of these with a Solar30 30amp controller.
Too much snow on the RV roof to plan for positioning just yet.

Or maybe just two of these:
150w Mono
However, wind load would be more of a problem installed up front.

120w poly should have about 7.6a Isc, like my old 120 had, but lately poly have been seen with a bit less Isc per watt. Not sure what is going on there.

So two 120s will be over 14a Isc already, aimed at the sun (less lying flat), and can be run with a $35 Solar30 PWM eg.

The 240 will do maybe 16a when aimed in hot sun and you will need a second (and MPPT) controller for it. An Eco-Worthy 20a at $102 will work for the one 240w panel. (IMO don't try it with the two 120s in series or you will exceed the Eco-W's Voc input limit.)

with just a couple of panels only producing around 6AMPS DC Current while in the high sun per day (Around 6-7 hours on Average per day) will just give a real good battery trickle charging event each day. Getting the most Dc Current from the panels would be my big desires.

Trying to use small things just off the panels alone is not be a big benefit for me and I think my best use for the panels will be to keep the batteries topped off. My batteries need to be in the 90% to 100% charge state to get their full performance spec from them. The grand idea for me is to never drop the batteries below their 12.0VDC (Approximately 50% charge state) without re-charging right away. Having this silent running trickle charge from the solar panels would be a big thing for my style of camping off the power grid.

I started out in baby steps and since 2009 have been using my 255AH battery bank camping of the power grid. Then I would run my 2KW Generator at 8AM each morning to re-charge the battery banks back to their 90% charge state using smart mode charging in a quick three hour generator run time.

I am just now starting to think SOLAR PANELS. By adding solar panels I think I cut down my generator run time to only around one hour per day to get past the initial high current demand of around 50AMPS DC Current and then the solar panels could provide the 15AMPS DC Current during the 6-7 hours of high SUN to get my battery bank up to the 90% or 100% charge state before I start using them again the next evening through the night. If my batteries never drops below the 90% charge state then I probably won't need to run the generator at all each day.

This is what I will be doing my new solar panels. I am planning to add two 120WATT panels on the front of roof and one larger 240WATT panel across the back of the roof on my OFF-ROAD POPUP camper. Hoping to get 15-20Amps DC Current during a typical high sun day. My back-up plan when NO SUN will be my 2KW Honda Generator. I consider the smart mode converter/charger system, larger battery bank, solar panels with controller, and 2KW Generator a must have for my style of camping off the power grid.

We do almost everything we would normally do at an electric camp ground camping off the power grid with the exception of using the high wattage Air Conditioner or High wattage Microwave. Our biggest drain off the batteries of course is between 6PM to 11PM keeping up with the favorite TV shows and the local weather radar conditions, keeping touch with the kids, paying some bills, some surfing on the internet. and playing with my Ham radio hehe... We light up our patio area just like we do at regular camp sites.

We give up flashlights and candles a long time ago but still have them around for emergencies.

Just some of my thoughts here on camping off the power grid using some solar panels to reduce my generator run times.

Roy Ken

There is no solar panel that is significantly better in the shade.
Panels are just a commodity. Shop by price, dimensions and output.

Post links to the panels you are considering for best answers.