best low light performance

Hi,

Let's get back on topic--which is Poly or Mono in low light.

We have a statement rule of thumb from a seller, that suggest mono gets the edge.

We have a real life test where the poly whipped the mono by a fairly substantial amount.

So folks poly or mono?

Just so as you know I will ask a mod to remove any post that does not address the above.

With your definition of good being different than the one most often used here. From a consumer point of view, if I buy a 100w panel, my question is what percentage of 100w am I getting in low light. You are using the definition used in industry which is valid for different uses, but does NOT answer the above question at all. Yours answers the question for a given square inch of roof area, which panel puts out the most watts under lab conditions. A very different question.

You keep quoting the latter statistics to answer the former question, when it does not apply.

Jim

HiTech wrote:

harold1946 wrote:

HiTech wrote:

harold1946 wrote:

HiTech wrote:

harold1946 wrote:

HiTech wrote:
Mine do the same.

Harold what do you have to back up your claim about efficiency beyond the standard test conditions of strong light? If we are talking efficiency, the relative efficiency from full sun to 50% or less light strength is what is interesting when discussing low light situations. Efficiency in full sunlight is interesting, but moot in low light discussions.

Jim

I have nothing other than the industry standard Tier rating, of which thin film is rated the lowest.
Do you have information to the contraty?

I saw nothing in there other than under standard lab test conditions, not low light.

Do you believe that efficiency would increase under low light or remain the same?

I believe it is not linear. There are junction thresholds to overcome. But what I believe is not relevant. What does the data show?

All data shows thin film (amorphous) is the least efficient of the four types of panels, and has the lowest power output per square foot of all, in all light conditions.

Output per square foot is not what we have discussed. Output in low light vs. nominal wattage is the topic of posts about amorphous panels being good in low light.

Jim

You are playing the semantics game. No one has said they were not good in low light, just not the "best" as was claimed.

All data showes the hybrids to be the best in low light, with mono
being second, poly third, and amorphous fourth.
Thin film technology was another step in the developmemt of PV's but has fallen by the wayside because of production cost, less power produced per square foot, and vulnerability to the elements, ie. UV and hail.
Its claim to fame was the ease of installation, even on surfaces with compound curves. Direct adhesion to a substrate without the need of framework. Power output is also less affected by heat than conventional panels,

pianotuna wrote:
Hi harold,

why-amorphous-panels-perform-well-in-low-light

and from:

Amorphous

" Having said that, for a given power rating, they do perform better at low light levels than crystalline panels - which is worth having on a dismal winter's day. "

and from:

post #1

"Amorphous panels are clearly the best for low light performance--but are relatively speaking huge."

I think---you should have googled better?

harold1946 wrote:
All data shows thin film (amorphous) is the least efficient of the four types of panels, and has the lowest power output per square foot of all, in all light conditions.

I found all of those and many others. Its quite easy to find an article to support ones view.

"Of the three basic solar panel types--monocrystalline, polycrystalline and amorphous--molycrystalline is the most efficient in collecting solar energy and therefore somewhat more effective in regions of low sunlight. Monocrystalline panel, while more efficient, are only slightly so."

From an SS MPPT-15, MS view showed .2 A output at 14.1 V, at sunset, MX-Solar 235W poly module. The batteries were at 98-100% SOC.

harold1946 wrote:

HiTech wrote:

harold1946 wrote:

HiTech wrote:

harold1946 wrote:

HiTech wrote:
Mine do the same.

Harold what do you have to back up your claim about efficiency beyond the standard test conditions of strong light? If we are talking efficiency, the relative efficiency from full sun to 50% or less light strength is what is interesting when discussing low light situations. Efficiency in full sunlight is interesting, but moot in low light discussions.

Jim

I have nothing other than the industry standard Tier rating, of which thin film is rated the lowest.
Do you have information to the contraty?

I saw nothing in there other than under standard lab test conditions, not low light.

Do you believe that efficiency would increase under low light or remain the same?

I believe it is not linear. There are junction thresholds to overcome. But what I believe is not relevant. What does the data show?

All data shows thin film (amorphous) is the least efficient of the four types of panels, and has the lowest power output per square foot of all, in all light conditions.

Output per square foot is not what we have discussed. Output in low light vs. nominal wattage is the topic of posts about amorphous panels being good in low light.

Jim

Hi harold,

why-amorphous-panels-perform-well-in-low-light

and from:

Amorphous

" Having said that, for a given power rating, they do perform better at low light levels than crystalline panels - which is worth having on a dismal winter's day. "

and from:

post #1

"Amorphous panels are clearly the best for low light performance--but are relatively speaking huge."

I think---you should have googled better?

harold1946 wrote:
All data shows thin film (amorphous) is the least efficient of the four types of panels, and has the lowest power output per square foot of all, in all light conditions.

HiTech wrote:

harold1946 wrote:

HiTech wrote:

harold1946 wrote:

HiTech wrote:
Mine do the same.

Harold what do you have to back up your claim about efficiency beyond the standard test conditions of strong light? If we are talking efficiency, the relative efficiency from full sun to 50% or less light strength is what is interesting when discussing low light situations. Efficiency in full sunlight is interesting, but moot in low light discussions.

Jim

I have nothing other than the industry standard Tier rating, of which thin film is rated the lowest.
Do you have information to the contraty?

I saw nothing in there other than under standard lab test conditions, not low light.

Do you believe that efficiency would increase under low light or remain the same?

I believe it is not linear. There are junction thresholds to overcome. But what I believe is not relevant. What does the data show?

All data shows thin film (amorphous) is the least efficient of the four types of panels, and has the lowest power output per square foot of all, in all light conditions.

harold1946 wrote:

HiTech wrote:

harold1946 wrote:

HiTech wrote:
Mine do the same.

Harold what do you have to back up your claim about efficiency beyond the standard test conditions of strong light? If we are talking efficiency, the relative efficiency from full sun to 50% or less light strength is what is interesting when discussing low light situations. Efficiency in full sunlight is interesting, but moot in low light discussions.

Jim

I have nothing other than the industry standard Tier rating, of which thin film is rated the lowest.
Do you have information to the contraty?

I saw nothing in there other than under standard lab test conditions, not low light.

Do you believe that efficiency would increase under low light or remain the same?

I believe it is not linear. There are junction thresholds to overcome. But what I believe is not relevant. What does the data show?

Hi harold,

I also get amps after sunset. Check to see the time of Civil Twilight in your area. I mostly get a tiny bit of charging sometime past that number. Sounds like I should do another "back yard" experiment.

Here is the data for today:

Actual Time sun rise 5:42 AM CST sun set 8:11 PM CST

I'll run out to the RV now as it is 7:50 and see what is what. Rv is in the shade of two houses and some large trees. Solar still charging but only barely. I'll be able to test better on May 1 as I'll be in a parking lot for the night--and should be able to get out of the shade.