Mono Panels VS Poly Panels Advantage. What Is It ?

Jim, I don't doubt that what you say is true as far as the output. However, there may be more at play than just that fact that one is mono and one is poly. You have two different manufacturers, different IV curves, different temperature coefficients, probably different panel ages. Panels also have a power tolerance, typically ±3 to ±5% even from the same manufacturer or batch.

It would be nice to see some real documentation on this widely believed but unverified topic. Some websites actually say that mono is better in low light and does slightly better than poly in higher heat. Other sites say that poly is better in low light and does better in higher heat. Whom do you believe? I would think that the actual specs for a panel under consideration would be more important than whether it is poly or mono.

Just to add.

My comparisons are not to be taken as any thing more than a CanadianSolar 220w mono vs a Schott 230w poly. I've had a few years to watch the Voc, Isc, and what they do with the Eco-worthy side by side in different lighting. A different controller or set of panels and you may have different results.

What happens to the relative efficiencies for equal watt panels when one has a lower Isc but is more efficient (smaller area) by watts?

It is the amps that charge the battery with PWM, not the watts. I would use Isc amps/panel area, not watts/area to rate their efficiencies.

Dave

Side by side the difference is bigger than 5% in any light. I mentioned above that the Poly out does the Mono in bright light 15a vs 12a here in East Denver, in shade the mono drops to .78a vs the polys 1.78a. Either situation is more than a 5% difference.

The only reason I'd chose mono for a RV is if the smaller size allowed for a extra panel where the poly would only have room for one. Grid tied on your house and low light isn't as much as a issue.

Has Consumer Reports done an article on this issue (and others) with regard to solar panel performance, testing and specification verification?

I'm in a poor position to find out unfortunately...

Thanks

Standard comparison.
Mono vs Poly

This article says that poly is maybe .5% better in low light. If your 200 watt panel is in the shade and only producing 25 watts, the poly panel would theoretically produce 25.125 watts. Could/would you even notice the difference?

Actually it says maybe .5% more per year in a fixed installation.

The biggest issue is efficiency which relates to panel size for equal watts and initial cost.

Great topic and very timely.

Here's a few links on the subject matter well worth a look over.

Monocrystalline or Polycrystalline?

Polycrystalline vs Monocrystalline Solar Modules

The smaller panel means higher efficiency.

250 must be near if not at the limit for the Eco-Worthy,'s 42V limit when you adjust for temperature, altitude, etc?

Be another month before I can try out my 230/Eco-W combo that I copied from JiminDenver's set-up. Also I could do a test swap of the EcoW MPPT and the PWM controllers on the 130w to get a comparison with Salvo's results on that.

Wonder what happened to our man from NC with the Tracer? :)

Another thing to consider is panels are just getting smaller. Solarblvd has 270w poly panels that are the size of my 220w mono and much smaller than my 230w poly. How that translates into low light performance I have no idea.

On craigslist here there is one person selling year old 230 watt polys for $190 and another selling new 250w polys for $200 but I think the later will require taxes paid. If I can get to the 230w panels in time to check them, I'll buy a match to my 230w. If not, I think I'll buy a pair of the 250w. That way I'll have a matched set to mount.

Hi Shadow,

Any idea what it is doing amp-wise in moonlight?

What brand of panel is it?

Shadow Catcher wrote:
My panel will put out 17V under a full moon.