Solar Panels: Mono vs Poly

OK, here's another question.

Comparing two panels, they are very similar electrically and dimensionally, but one (Canadian Solar CS5A-200M) claims a "Snow Load" of <5400, and the other (Sunny Power SPM195W) has a max load of only <2400.

Seems to me the one with the higher load number would be more rugged, and better for an RV application. What do you think?

EDIT: Called the Sunny Power retailer. They have the same snow load limit <5400pa as the Canadian Solar panels. Their reported <2400pa load is for Wind, which Canadian Solar doesn't report.

I get the impression that all recent panels in this 32"x60", 180-205 Watt range have the same load rating: wind <2400pa, snow <5400pa.

Yes, you can skip both display and data converter.

But dip switches have limits to what values and in what increments they can change. Basically, with dip switches you have a choice of 3 values for each setpoint, ex. Float =13,2, or 13.4 or 13.8. If I were to buy 2024, at the very least I would get a data converter to do fine tuning, using a laptop as display. After having played with adjustments enough, you can leave it alone and only look at those LED indicators occasionally.

In my 3048 there is unbelievable variety of functions, modes and values that you can adjust with buttons, and see the results on built-in display.

There are dip switches on the 20A Rogue. I'd skip the display and get the data converter. If you don't want the data converter now, just roll with the dip switches.

Don't know about dip switches in 20A model - maybe. Didn't read its manual. Judging by my 3048, their engineers are very thorough and don't skip on important things.

Almot wrote:

...
If there is even a slight chance that you might need more than 300W solar in future, - skip Rogue 2024 and go for 3048.

Yes, that's what I'm thinking. Under the NOCT (Normal Operating Cell Temperature) test the panels I would like put out 296W. Higher under optimum conditions.

And for the price of the 20A Rogue with the remote display I can get the 30A with a built-in display.

I've been wanting a setup with one of these things since they first came out. Hopefully this summer it will happen. Panel prices have certainly dropped ...

By the way, I understand you can do the settings on the 20A version with dip switches in the box.

12thgenusa wrote:
The 3024 is no longer available, replaced by the 3048. I really like the 3024, suits my needs just fine. Not sure if it is a function of panels or controller or other conditions, but I have seen a more than 370 watt output often enough that is not a fluke.

New 3048 you would like even better than 3024. It has higher input voltage limit and added reversed polarity protection. Some upgrades in firmware as well, - like "slave" function to synchronize 2 or more Rogues if you need to, ex. when expanding the system. I would say, up to 450-480W flat panels this is the best controller that can be.

As to the initial question - mono vs poly - very little difference, not worth sweating about.

Keep in mind that 20A Rogue has no display and no control buttons, only LED indicators. So, to adjust settings, you have to either add an optional remote display (it has control buttons), or an optional Data Converter - this one would let you adjust the settings via laptop, if I understood correctly. Display is fun and very convenient, but not 100% necessary after you've adjusted the settings AND if you have some battery monitor or V/A meter. After adjusting the settings, you won't have to mess with it.

If there is even a slight chance that you might need more than 300W solar in future, - skip Rogue 2024 and go for 3048.

The 3024 is no longer available, replaced by the 3048. I really like the 3024, suits my needs just fine. Not sure if it is a function of panels or controller or other conditions, but I have seen a more than 370 watt output often enough that is not a fluke.

JiminDenver wrote:
I saw 180w panels (30v Voc) that were close to 32 inches this morning.

In a situation where you may have different sized panels filling spaces on the roof, I think PWM is the better way to go. Different wattages in high voltage panels means different Voc's and that can mess with a MPPT controller ability to track. 12v panels are 12v panel no matter if they are 80w or 150w.

Well I don't have any other panels, so will be buying a pair of the same type. And yes I'd like the Voc to be 30V or higher so I can run the panels in parallel and not have any large losses in the line to the MPPT controller. It's my understanding that when run in parallel, shading of one panel will not affect the other.

Currently looking for Canadian Solar CS5A-205M with a Voc of 37.7V and Ioc of 5.43A, not sure if I can get them at a good price though.

I saw 180w panels (30v Voc) that were close to 32 inches this morning.

In a situation where you may have different sized panels filling spaces on the roof, I think PWM is the better way to go. Different wattages in high voltage panels means different Voc's and that can mess with a MPPT controller ability to track. 12v panels are 12v panel no matter if they are 80w or 150w.

I've read about some "hybrid" panels that use both so the panel can work decently in both shade/overcast conditions as well as direct sun. However, I forgot who was making these. If they lived to the hype, for the precious space on the top of a RV, they would be the best tool for the job.

However, if one had a portable frame with panels on it, then the need to maximize every square inch is less important.

Same with a MPPT controller. For the limited panel space on a roof, one needs every single possible watt, so a MPPT controller goes without saying. For a frame or array where space isn't as important, a PWM controller might suffice because one can add panels fairly easily.