Mono vs Poly in low light?

[LETitROLL]

Most of what I have read has lead me to believe that Mono panels are better in low light situations (cloudy, etc) than poly (all else being equal). I am looking at a couple of panels that will only be used in winter, and in a northern location with overall low solar isolation. I would like to know of any direct experience anyone might have of using or comparing the 2 types under cloudy skies.
thanks

[inetdog]

Most of what I have read has lead me to believe that Mono panels are better in low light situations (cloudy, etc) than poly (all else being equal). I am looking at a couple of panels that will only be used in winter, and in a northern location with overall low solar isolation. I would like to know of any direct experience anyone might have of using or comparing the 2 types under cloudy skies.
thanks

Do not confuse low light with diffuse light. The two are different in their interaction with solar PV.
Low but direct light should scale very close to full sun performance in terms of efficiency.
Diffuse/indirect light is a more interesting situation, but the output of the panels will be low whatever type you use.
In terms of efficiency in converting incoming diffuse light to energy, the decrease in efficiency compared to direct light will be better for amorphous panels than for crystalline (either mono or poly). But the lower starting efficiency of amorphous at full light can still leave the results with diffuse light worse in absolute terms of power per unit area.

I have not seen authoritative results of a particularly significant difference between mono and poly for diffuse light that favors mono. Do you have some references you can point out?

[jimindenver]

Right now I am using a 245w mono side by side with a 250w poly with identical controllers/ set ups and the poly is winning in bright and lower light. The poly doesn't get as high of Voc but it also doesn't drop as fast when the light dims a bit. The mono will drop from 17a output on a MPPT controller to 2.38a as soon as the light clouds come in and will be asleep when the poly is still kicking out 4 and 5 amps when you can barely tell where the sun is. This is in a RV off grid where those 5 amps can keep us off the generator if we behave. With three panels producing 15a total, we might cut back on the microwave usage.

I also saw this on my original set of panels, a Canadian solar 220w mono and a Schott 230w poly three years ago. The difference then was the mono is considerable smaller than the poly. The 245w and 250w above have the same footprint.

Now according to all the "test" (advertising) , this is wrong and really I'm just a guy in his drive with meters, controllers and such. The thing is I am not advertizing anything, just report what I see side by side in a off grid RV type situation.

[LETitROLL]

Right now I am using a 245w mono side by side with a 250w poly with identical controllers/ set ups and the poly is winning in bright and lower light. The poly doesn't get as high of Voc but it also doesn't drop as fast when the light dims a bit. The mono will drop from 17a output on a MPPT controller to 2.38a as soon as the light clouds come in and will be asleep when the poly is still kicking out 4 and 5 amps when you can barely tell where the sun is. This is in a RV off grid where those 5 amps can keep us off the generator if we behave. With three panels producing 15a total, we might cut back on the microwave usage.

I also saw this on my original set of panels, a Canadian solar 220w mono and a Schott 230w poly three years ago. The difference then was the mono is considerable smaller than the poly. The 245w and 250w above have the same footprint.

Now according to all the "test" (advertising) , this is wrong and really I'm just a guy in his drive with meters, controllers and such. The thing is I am not advertizing anything, just report what I see side by side in a off grid RV type situation.

That is kind of what I was wondering, I have not seen anything other than what could be classified as rumors, but it is mostly from people with a dog in the fight. I would think panels from a few years ago of either type may not perform as well as the latest ones because of advancements that have been made in efficiency (that may just be another misconception)?
thanks

I am mostly concerned about performance during significant cloud cover, I have been told (by renogy) that will be way down in the 10 - 15% of rated output range (depending on variables).

[ButchDeal]

Most of what I have read has lead me to believe that Mono panels are better in low light situations (cloudy, etc) than poly (all else being equal). I am looking at a couple of panels that will only be used in winter, and in a northern location with overall low solar isolation. I would like to know of any direct experience anyone might have of using or comparing the 2 types under cloudy skies.
thanks

You may be asking the wrong question here. Generally you can get more poly watts for the dollar than mono watts. The difference in output between two equal watt Poly vs mono modules would be small but the difference in output of an equal COST poly vs mono array would be significant.