Polycrystalline vs Monocrystalline solar panels

Mike Harding · Guru

Polycrystalline vs Monocrystalline solar panels

Tony Bev · Guru

Hi Mike

I am not a techi, but going from memory here

Monocrystalline are more efficient than Polycrystalline panels, due to the way the crystal is manufactured

This means (to me being a layman), that Polycrystalline panels will be larger, for the same output as Monocrystalline panels

As a caravan roof also has hatches and aircons, then space is limited

As I have a motorhome, with a luton peak (hump) on the front, then I have less space for solar panels

I have Monocrystalline panels, on my motorhome, as they are smaller in area than the Polycrystalline, for the same wattage output

Whenarewethere · Guru

I have polycrystalline, but it was the only size panel I could find that would fit a space. Nothing wrong with the performance.

Probably more important that it is not a no name brand with unrealistic specifications.

Avoid plastic corners holding the frame together.

Buzz Lightbulb · Guru

I heard a very long time ago, probably 13 years, that one of them will still keep working if part of the panel is in shade whereas the other will stop producing power. Don't take my word thought. It was a long time ago and they've improved a lot since then.

Whenarewethere · Guru

There is information in my 6x20watt setup thread, with some experiments on various shadows.

Mike Harding · Guru

Whenarewethere wrote:
There is information in my 6x20watt setup thread, with some experiments on various shadows.

Link please?

Whenarewethere · Guru

Mike Harding wrote:
Whenarewethere wrote:
There is information in my 6x20watt setup thread, with some experiments on various shadows.
Link please?

https://thegreynomads.activeboard.com/t65231112/custom-6x20-watts-solar-setup-with-mppt/

Mike Harding · Guru

As no one has answered my question I'll answer it myself - some symmetry in that I think :)

After a couple of days doing extensive internet searches my conclusion is that there is no difference worth worrying about between the two solar panel construction techniques.

Jaahn · Guru

Mike Harding wrote:
As no one has answered my question I'll answer it myself - some symmetry in that I think :)
After a couple of days doing extensive internet searches my conclusion is that there is no difference worth worrying about between the two solar panel construction techniques.

Hi Mike smile

Late to the table but here now ! I agree with your conclusion. I have had both and working together in parallel and never noticed any difference. Possibly I could have measured some but certainly none that caused me to break out a meter to see how much wink

By the way Buzz this statement is BS, IMHO; "one of them will still keep working if part of the panel is in shade whereas the other will stop producing power." Indeed it was never true before either !!

Jaahn

Buzz Lightbulb · Guru

I guess it was a salesman pitch back in 2008.

Warren-Pat_01 · Guru

G'day Mike,
In the good old days, Yes - one was better than the other but these days they are both "horses for courses."

There are some panels that work well in shaded or partially shaded conditions - it's the way the cell are joined on the panel where a cell or more or more slightly reduces the output rather than dramatically as in the past.

Warren-Pat_01 · Guru

whenarewethere,
Thanks for sharing your set up - I too started & ended with 20w panels - they fitted in the side boot of our Jayco camper well & were lighter than a lot of larger panels that were available then.

When I get a little more time I'll read your info more fully & may make some changes to my set up (2 lots of 3x20w panels).

Whenarewethere · Guru

At the end of the day go for quality with some redundancy built in.

I don't think anyone really wants to be in the outback with a failed third rate setup & no options.

Gregoryrg · Member

I'd go with polycrystalline panels for 100W panels. The extra cost of monocrystalline panels isn't worth it for such small panels. Polycrystalline panels are still very efficient and reliable.
As for appearance, I think either type of panel would look good on a black roof. It really comes down to personal preference. I personally like the look of monocrystalline panels, but polycrystalline panels are also fine.

Gregoryrg · Member

Regarding aesthetics, both polycrystalline and monocrystalline solar panels can blend well with a black roof. Polycrystalline panels generally have a more uniform appearance, while monocrystalline panels exhibit a more distinct crystalline pattern. The choice between the two ultimately comes down to personal preference.

-- Edited by Gregoryrg on Thursday 30th of November 2023 03:37:37 AM

Scubadoo · Veteran Member

We have 3x 270W rated solar panels on our motorhome roof. All indentical dimensions.
1x 9 year old mono, 1x 9 year old poly and a 4 year old "mono perc".

I would challenge anyone to identify which is which by output measurement alone.
They are all within 1% at any time of the day. 18A each into our 12V battery on a good day.
A plus or minus 200mA diffence is irrelevant.

.

yobarr · Guru

Scubadoo wrote:
We have 3x 270W rated solar panels on our motorhome roof. All indentical dimensions.
1x 9 year old mono, 1x 9 year old poly and a 4 year old "mono perc".

I would challenge anyone to identify which is which by output measurement alone.
They are all within 1% at any time of the day. 18A each into our 12V battery on a good day.
A plus or minus 200mA diffence is irrelevant.

Interesting claim. Polycrystalline is recognised as a low-light panel, out-performing monocrystalline in that situation. Cheers

TimTim · Guru

yobarr wrote:
Scubadoo wrote:
We have 3x 270W rated solar panels on our motorhome roof. All indentical dimensions.
1x 9 year old mono, 1x 9 year old poly and a 4 year old "mono perc".

I would challenge anyone to identify which is which by output measurement alone.
They are all within 1% at any time of the day. 18A each into our 12V battery on a good day.
A plus or minus 200mA diffence is irrelevant.
Interesting claim. Polycrystalline is recognised as a low-light panel, out-performing monocrystalline in that situation. Cheers

Ummm change that statement around as monocrystalline perform better in low light.

But the downside is monocrystalline panels are not as efficient in heat.

What percentage difference in output for the two types of panels well I have no idea, but it only has to be a minor difference and the claims can be made. Would the average person notice the difference? Probably not!

With the ever advancing changes in technology one does not know whether past statement and findings hold up in todays environment. We now have Perc cells and double sided panels But the double sided ones appear to only produce about 5% more output if that. smile

Tim

-- Edited by TimTim on Thursday 30th of November 2023 09:29:34 PM

Burt65 · Veteran Member

TimTim wrote:

Ummm change that statement around as monocrystalline perform better in low light.
But the downside is monocrystalline panels are not as efficient in heat.
What percentage difference in output for the two types of panels well I have no idea, but it only has to be a minor difference and the claims can be made. Would the average person notice the difference? Probably not!
With the ever advancing changes in technology one does not know whether past statement and findings hold up in todays environment. We now have Perc cells and double sided panels But the double sided ones appear to only produce about 5% more output if that.

Tim

-- Edited by TimTim on Thursday 30th of November 2023 09:29:34 PM

Are you sure about that?

https://solarmagazine.com/solar-panels/monocrystalline-vs-polycrystalline-solar-panels/

"Temperature Coefficient

In warm weather, monocrystalline solar panels can deliver higher efficiency because of their higher temperature coefficient. The output degradation in monocrystalline panels is lower as the temperature rises. If you are living in a region where the summers are longer and warmer, you should carefully consider the temperature coefficient of the solar panels you are choosing."

https://www.energysage.com/solar/monocrystalline-vs-polycrystalline-solar/

"Temperature coefficient

Like efficiency, monocrystalline solar panels tend to outperform polycrystalline models regarding temperature coefficient. A panel's temperature coefficient is essentially a measure of how well it performs in warm temperatures (with percentages closer to zero being better), so it follows that monocrystalline solar panels have a better track record in high temperatures."

https://solarcalculator.com.au/solar-panels/monocrystalline-vs-polycrystalline/

"High heat tolerance

Mono panels perform better than their counterparts in high temperatures. Solar panels in high temperature produce less electricity, but mono panels have a higher resistance to heat helping them to perform better."

https://ases.org/monocrystalline-vs-polycrystalline-solar-panels/

"Another great factor that is greatly overlooked is the temperature coefficient.

The temperature coefficient is a measurement of how well the solar cell functions when the temperature rises.

In other words, it indicated the efficiency loss for every degree the temperature rises.

How Temperature Affects Monocrystalline Solar Panels Efficiency?

Most monocrystalline solar cells have a temperature coefficient of around -0.3% / C to -0.5% / C.

So when the temperature rises 1 degree Celsius or 32 degrees Fahrenheit, the monocrystalline solar cell will temporarily lose 0.3% to 0.5% of its efficiency.

How Temperature Affects Polycrystalline Solar Panels Efficiency?

Polycrystalline PV cells have a higher temperature coefficient than the monocrystalline ones.

This means that polycrystalline panels will lose more of their efficiency when the temperature rises making them not optimal to be used in hot areas."

Pretty much every single site in the world does agree on Mono being more temperature efficient than the Poly..

Just saying...

Whenarewethere · Guru

One more factor. What panel actually fits the available space. It's why I used 6 x 20 watt panels. Not the most efficient panel, but they fitted a space.

The side benefit using 6 panels, is redundancy.