best low light performance

Mono wins the harvest crown by just a smidge of efficiency, AFAIK, but I think the poly is a good choice. I had the real-time numbers for a 235w poly module and was surprised by the amount of power even in low light conditions. It wasn't much but it was right before sunset.
Let us know what modules you end up with, please.

Hi Jim,

Thanks--I'll go with the poly panels.

JiminDenver wrote:
Don

Harold wont like my answer either but you seen the results of my 220w mono compared to the 230w poly where the poly produced 33% (or better)more amps in almost all light. Bright sun.. poly 15a, mono 12 amp, total overcast poly 1.78 amp, mono .78 amp. Those are MPPT numbers as I don't get real time amps coming in and yes the poly is 10 watts bigger. Still that's a big difference in amps for a small difference in watts.

I would suggest that if you are picking these up in person to do a simple SOC test side by side.

Hi harold,

Just google it.

Pianotuna: I am still requesting the information referencing your claim that amorphous cells produce more power under low light conditions.

harold1946 wrote:
I will have to respectfully disagree. Lower efficiency, cheaper construction, little or no warranty, lack of blocking diods, do not equal best bang per buck in my book.
Quality panels can last 40+ years.

Same dimentions same wattage how do you measure efficiency?

Cheaper contruction? I have never read a post of these things self combusting or any other failure. Anyone have the frame suddenly fall apart or cells shifting around?

Warranties seem all about the same. Never heard a claim for long term performance issues.

You don't need blocking diodes with any decent controller. All 24v panels that I have looked at have bypass diodes as they are expected to be used in series.

I would expect any of these panels to last 40 years. Have not really read about off brands failing early.

I would like to see a link to the FUD.

Don

Harold wont like my answer either but you seen the results of my 220w mono compared to the 230w poly where the poly produced 33% (or better)more amps in almost all light. Bright sun.. poly 15a, mono 12 amp, total overcast poly 1.78 amp, mono .78 amp. Those are MPPT numbers as I don't get real time amps coming in and yes the poly is 10 watts bigger. Still that's a big difference in amps for a small difference in watts.

I would suggest that if you are picking these up in person to do a simple SOC test side by side.

doughere wrote:
"Just choosing by price per watt, one can also be setteling for less efficiency"
True:


But:
Price per watt is usually best bang per buck.

Doug

I will have to respectfully disagree. Lower efficiency, cheaper construction, little or no warranty, lack of blocking diods, do not equal best bang per buck in my book.
Quality panels can last 40+ years.

Hi mena,

No, I did not "put it on the table". I asked which was more likely to do well in low light mono, or poly. harold is just muddying the waters.

I am considering mono or poly. Amorphous, nice as they are, just take too much space. There are thousands of references to amorphous and low light. But that is NOT my question.

I apologize if my question was unclear.

mena661 wrote:

smkettner wrote:
Harold, there are two choices. Why strongly debate a choice that is not even on the table?

You may as well recommend a generator :R

Don mentioned amorphous in his first post. He put it on the table but I agree we can move on.

"Just choosing by price per watt, one can also be setteling for less efficiency"
True:


But:
Price per watt is usually best bang per buck.

Doug

Just for reference; The highest effieiency rating achieved so far for Amorphous "thin film" solar cells was accomplished by engineers at First Solar, being rated at 10.7% efficient.
Conventional cells have in some cases a rating of as low as 10% to as high as 20%.
Using those figures alone comparing the top rated amorphous to any other top rated type, the amorphous starts out with a 9.3 % deficiency.
Another one of those things many overlook when considering the purchase of solar panels.
Just choosing by price per watt, one can also be setteling for less efficiency.